Diagnostic Trouble Code (DTC) P0320

[miesk5]

Yo,

But this set of tests includes use of Ford's old Break-Out Box; so, as I mentioned in another thread here; In place of the break-out box, go to the EEC  V connector pin instead; Substitute EEC V connector pin Number for breakout box number


PCM Connector Pin-Out Diagram with Circuit Functions in a 96 5.0 and 5.8
Pin Number Circuit Circuit Function 
Iggie the  ? Marks.
1 315 (P/O) PCM to Transmission Shift Solenoid No. 2 
2 658 (P/LG) PCM to Check Engine Indicator Lamp 
3 � Not Used 
4 � Not Used 
5 � Not Used 
6 651 (BK/Y) Dedicated Ground 
7 � Not Used 
8 � Not Used 
9 � Not Used 
10 � Not Used 
11 � Not Used 
12 � Not Used 
13 107 (P) PCM Flash EEPROM Power Supply 
14 784 (LB/BK) 4x4 Low Range Switch to PCM Indicator Lamp 
15 915 (PK/LB) J1850 Bus Negative/Data Negative (Return) to PCM 
16 914 (T/O) J1850 Bus Positive/Data Positive 
17 � Not Used 
18 � Not Used 
19 � Not Used 
20 � Not Used 
21 � Not Used 
22 � Not Used 
23 259 (O/R) Dedicated Ground to TFI Module 
24 570 (BK/W) Dedicated Ground � PCM 
25 875 (BK/LB) Ground Logic Module 
26 � Not Used 
27 237 (O/Y) PCM to Transmission Shift Solenoid No. 1 
28 � Not Used 
29 224 (T/W) Transmission Overdrive Cancel Switch to PCM 
30 � Not Used 
31 � Not Used 
32 � Not Used 
33 676 (PK/O) Vehicle Speed Sensor � Negative (Return) to PCM 
34 � Not Used 
35 392 (P/LG) Heated Exhaust Gas Oxygen Sensor No. 3 to PCM 
36 968 (T/LB) Mass Airflow Return 
37 923 (O/BK) Transmission Oil Temperature to PCM 
38 354 (LG/R) Engine Coolant Temperature Sensor to PCM 
39 743 (GY) Air Charge Temperature Sensor to PCM 
40 238 (DG/Y) Fuel Pump Monitor to PCM/Fuel Pump Relay to Safety Switch 
41 198 (DG/O) A/C Pressure Switch to Control Relay 
42 � Not Used 
43 � Not Used 
44 200 (BR) PCM to Air Management No. 2 (Was TAD) 
45 � Not Used 
46 � Not Used 
47 360 (BR/PK) PCM to Electronic Vacuum Regulator � Constant Current 
48 382 (Y/BK) PCM to Test Connector No. 2 
49 395 (GY/O) Profile Ignition Pickup to PCM 
50 929 (PK) PCM to Spark Angle Pulse Width/Spark Output 
51 570 (BK/W) Dedicated Ground � PCM 
52 � Not Used 
53 924 (BR/O) PCM to Transmission Coast Clutch Solenoid 
54 480 (P/Y) PCM to Transmission Converter Clutch Control 
55 37 (Y) Battery to Load 
56 191 (LG/BK) PCM Top Vapor Management Valve � Constant Current 
57 310 (Y/R) Knock Sensor No. 1 to PCM 
58 679 (GY/BK) Vehicle Speed Sensor � Positive to PCM 
59 917 (DG/LG) Misfire Detection Sensor � Feed 
60 74 (GY/LB) Heated Exhaust Gas Oxygen Sensor No. 1 to PCM 
61 � Not Used 
62 � Not Used 
63 � Not Used 
64 199 (LB/Y) Manual Lever Position Sensor to PCM 
65 352 (BR/LG) Delta Exhaust Pressure Transducer to PCM 
66 � Not Used 
67 � Not Used 
68 � Not Used 
69 � Not Used 
70 190 (W/O) PCM to Air Management No. 1 (Was TAB) 
71 361 (R) Power Output from PCM Relay 
72 561 (T/R) PCM to Fuel Injector No. 7 Cylinder 
73 559 (T/BK) PCM to Fuel Injector No. 5 Cylinder 
74 557 (W) PCM to Fuel Injector No. 3 Cylinder 
75 555 (T) PCM to Fuel Injector No. 1 Cylinder or Bank No. 1 
76 570 (BK/W) Dedicated Ground � PCM 
77 570 (BK/W) Dedicated Ground � PCM 
78 � Not Used 
79 911 (W/LG) PCM to Output Circuit Indicator Lamp/Overdrive Cancel Indicator 
80 926 (LG/O) PCM to Fuel Pump Relay Control 
81 925 (W/Y) PCM to Electronic Pressure Control No. 1 
82 � Not Used 
83 264 (W/LB) PCM to Idle Speed Control Motor No. 1 
84 136 (DB/Y) Output Shaft Speed to PCM 
85 � Not Used 
86 � Not Used 
87 94 (R/BK) Heated Exhaust Gas Oxygen Sensor No. 2 to PCM 
88 967 (LB/R) Mass Air Flow Sensor to PCM 
89 355 (GY/W) Throttle Position Sensor to PCM/Diesel Fuel Injector Pump Lever Sensor 
90 351 (BR/W) Power to Engine Sensors 
91 359 (GY/R) Sensor Signal Return 
92 511 (LG) Stoplamp (Brake On/Off) Switch to Stoplamps 
93 387 (R/W) HEGO Sensor Heater Voltage Monitor No. 1 to PCM 
94 388 (Y/LB) HEGO Sensor Heater Voltage Monitor No. 2 to PCM 
95 389 (W/BK) HEGO Sensor Heater Voltage Monitor No. 3 to PCM 
96 � Not Used 
97 361 (R) Power Output from PCM Relay 
98 562 (LB) PCM to Fuel Injector No. 8 Cylinder 
99 560 (LG/O) PCM to Fuel Injector No. 6 Cylinder 
100 558 (BR/LB) PCM to Fuel Injector No. 4 Cylinder 
101 556 (W) PCM to Fuel Injector No. 2 Cylinder or Bank No. 2 
102 � Not Used 
103 570 (BK/W) Dedicated Ground � PCM 
104 � Not Used


A1 ATTEMPT TO CRANK ENGINE





NOTE


Note: Verify Inertia Fuel Shutoff (IFS) switch is set (button pushed in). Refer to Owner Guide for location.




Does engine crank?


Yes


No


GO to A2.


REFER to Group 03 in Service Manual.


A2 IDENTIFY TYPE OF NO START





NOTE


Note: The purpose of this Test Step is to identify intermittent No Starts in order to guide the technician to the proper repair procedure.




Does the vehicle start now?


Yes


No


Vehicle is an intermittent No Start. GO to Pinpoint Test Step Z50and prepare to use the Ignition Intermittent Analyzer, DIST tool.


Natural Gas Crown Victoria:

GO to A15.

3.0L Windstar:

GO to A3.

All Others:

GO to A4.


A3 CHECK MIL DURING CRANK

• Key off.
  
• Key on, observe Malfunction Indicator Lamp (MIL). MIL should be on, if not, go to Pinpoint Test Step NB1
  
• Turn the key to start position and observe MIL while cranking the engine.
  

Did the MIL turn off during crank?


Yes


No


MIL turning off during crank indicates PIP circuit is OK. GO to A4.


GO to A6.


A4 CHECK FOR VREF AT THROTTLE POSITION (TP) SENSOR

• Key off.
  
• Disconnect TP sensor.
  
• Key on, engine off.
  
• Measure voltage between VREF circuit and SIG RTN circuit at the TP sensor vehicle harness connector.
  

Is voltage between 4.0 and 6.0 volts?


Yes


No


RECONNECT TP sensor. GO to A5.


GO to Pinpoint Test Step C1.


C1 IS VREF GREATER THAN 6.0 VOLTS?



C2 CHECK BATTERY VOLTAGE


Is VREF greater than 6.0 volts?


Yes


No


GO to C35(to check VREF for short to power).


GO to C2.


C2 CHECK BATTERY VOLTAGE

• Key on, engine off.
  
• Measure voltage across battery terminals.
  

Is voltage greater than 10.5 volts?


Yes


No


GO to C3.


Key off. REFER to the Charging/Electrical Group in the Service Manual to service discharged battery.


C3 CHECK SIG RTN CIRCUIT TO SENSOR WHERE VREF CHECK FAILED

• Key on, engine off.
  
• Sensor where VREF check failed disconnected.
  
• Measure voltage between battery positive post and SIG RTN circuit at the appropriate sensor vehicle harness connector.
  

Is voltage greater than 10.5 volts and within 1.0 volt of battery voltage?


Yes


No


GO to C4.


SIG RTN/PWR GND fault present. GO to C25.


C4 CAN THE ECT PID BE ACCESSED?

• Key on, engine off.
  
• Attempt to access the ECT PID.
  

Can the ECT PID be accessed?


Yes


No


GO to C20(to check VREF for opens).


GO to C5(to check for VPWR, and VREF for shorts).


C5 CHECK FOR VPWR TO IAC SOLENOID

• Key off.
  
• TP sensor disconnected.
  
• Disconnect Idle Air Control (IAC) solenoid.
  
• Key on, engine off.
  
• Measure voltage between the VPWR circuit at the IAC vehicle harness connector and the battery negative post.
  
• Key off.
  

Was voltage greater than 10.5 volts?


 







Yes


No


RECONNECT IAC solenoid.

For Probe:

GO to C13.

All Others:

GO to C6.


VPWR is not present. RECONNECT TP sensor.

For applications with EEC-V Power Relay inside CCRM (Mustang, Taurus/Sable and Thunderbird/Cougar):

GO to Pinpoint Test Step X1.

All others:

GO to Pinpoint Test Step B1.


C6 CHECK FOR SHORTED DPFE OR EGR VALVE POSITION SENSOR

• Key off.
  
• TP sensor disconnected.
  
• Disconnect DPFE sensor (EGR valve position sensor for 5.0L Explorer).
  
• Key on, engine off.
  
• Again measure voltage between VREF and SIG RTN circuits at the TP sensor vehicle harness connector.
  
• Key off.
  

Was voltage between 4.0 and 6.0 volts?


Yes


No


REPLACE DPFE sensor (EGR valve position sensor for 5.0L Explorer). RECONNECT all components. RERUN Quick Test.


For applications with a Fuel Tank Pressure (FTP) sensor (Taurus/Sable, Crown Victoria (ex. NG)/Grand Marquis, Town Car, Explorer, 4.2L F-Series and 4.6L F-Series):

GO to C7.

For applications with an A/C Pressure (ACP) sensor (******/Tracer, Continental and Mark VIII):

GO to C8.

For applications with Power Steering Pressure (PSP) sensor (2.0L Contour/Mystique):

GO to C10.

For applications with Injection Pressure (IP) sensor (NG Crown Victoria):

GO to C11.

All others:

GO to C15.


C7 CHECK FOR SHORTED FTP SENSOR

• Key off.
  
• TP and DPFE sensors disconnected.
  
• Disconnect FTP sensor.
  
• Again, measure voltage between the VREF and SIG RTN circuits at the TP sensor vehicle harness connector.
  
• Key off.
  

Was voltage between 4.0 and 6.0 volts?


Yes


No


REPLACE the FTP sensor. RECONNECT all components. RERUN Quick Test.


GO to C15.


C8 CHECK FOR SHORTED ACP SENSOR

• Key off.
  
• TP and DPFE sensors disconnected.
  
• Disconnect ACP sensor.
  
• Key on, engine off.
  
• Again measure voltage between the VREF and SIG RTN circuits at the TP sensor vehicle harness connector.
  
• Key off.
  

Was voltage between 4.0 and 6.0 volts?


Yes


No


REPLACE ACP sensor. RECONNECT all components. RERUN Quick Test.


For Continental equipped with optional Traction Control (with TP-B sensor):

GO to C9.

All others:

GO to C15.


C9 CHECK FOR SHORTED TP-B SENSOR

• Key off.
  
• TP, DPFE and ACP sensors disconnected.
  
• Disconnect Throttle Position sensor B (TP-B).
  
• Key on, engine off.
  
• Again measure voltage between VREF and SIG RTN circuits at the TP sensor vehicle harness connector.
  
• Key off.
  

Was voltage between 4.0 and 6.0 volts?


Yes


No


REPLACE TP-B sensor. RECONNECT all components. RERUN Quick Test.


GO to C15.


C10 CHECK FOR SHORTED PSP SENSOR

• Key off.
  
• TP and DPFE sensors disconnected.
  
• Disconnect PSP sensor.
  
• Again, measure voltage between the VREF and SIG RTN circuits at the TP sensor vehicle harness connector.
  
• Key off.
  

Was voltage between 4.0 and 6.0 volts?


Yes


No


REPLACE the PSP sensor. RECONNECT all components. RERUN Quick Test.


GO to C15.


C11 CHECK FOR SHORTED IP SENSOR

• Key off.
  
• TP and DPFE sensors disconnected.
  
• Disconnect IP sensor.
  
• Again, measure voltage between the VREF and SIG RTN circuits at the TP sensor vehicle harness connector.
  
• Key off.
  

Was voltage between 4.0 and 6.0 volts?


Yes


No


REPLACE the IP sensor. RECONNECT all components. RERUN Quick Test.


GO to C15.


C13 CHECK FOR SHORTED EGRP SENSOR

• Key off.
  
• TP sensor disconnected.
  
• Disconnect EGR Position (EGRP) sensor.
  
• Key on, engine off.
  
• Again, measure voltage between the VREF and SIG RTN circuits at the TP sensor vehicle harness connector.
  
• Key off.
  

Was voltage between 4.0 and 6.0 volts?


Yes


No


REPLACE EGRP sensor. RECONNECT all components. RERUN Quick Test.


GO to C14.


C14 CHECK FOR SHORTED EGRB SENSOR

• Key off.
  
• TP and EGRP sensors disconnected.
  
• Disconnect EGR Boost (EGRB) sensor.
  
• Key on, engine off.
  
• Again, measure voltage between the VREF and SIG RTN circuits at the TP sensor vehicle harness connector.
  
• Key off.
  

Was voltage between 4.0 and 6.0 volts?


Yes


No


REPLACE EGRB sensor. RECONNECT all components. RERUN Quick Test.


GO to C15.


C15 CHECK VPWR TO PCM

• Key off.
  
• TP sensor disconnected.
  
• All other sensors wired to VREF disconnected from previous test steps (if necessary, refer to Sensors Connected ToVREF chart at the beginning of this pinpoint test).
  
• Disconnect PCM. Inspect for damaged or pushed out pins, corrosion, loose wires, etc. Service as necessary.
  
• Install breakout box, leave PCM disconnected.
  
• Key on, engine off.
  
• Measure voltage between Test Pin 71 (VPWR) and Test Pin 77 (PWR GND) at the breakout box.
  

Is voltage greater than 10.5 volts?


Yes


No


GO to C16.


SERVICE open VPWR circuit between PCM and splice to IAC solenoid. REMOVE breakout box. RECONNECT all components. RERUN Quick Test.


C16 CHECK VREF CIRCUIT FOR SHORT TO GROUND OR SIG RTN

• Key off.
  
• TP sensor disconnected.
  
• All other sensors wired to VREF disconnected.
  
• Breakout box installed, PCM disconnected.
  
• Disconnect Scan Tool from DLC.
  
• Measure resistance between Test Pin 90 (VREF) and Test Pins 51 or 103 (PWR GND) and 91 (SIG RTN) at the breakout box.
  

Is each resistance greater than 10,000 ohms?


Yes


No


REPLACE PCM. REMOVE breakout box. RECONNECT all components. RERUN Quick Test.


SERVICE VREF short to ground. REMOVE breakout box. RECONNECT all components. RERUN Quick Test.


C20 CHECK VREF CONTINUITY TO PCM

• Key off.
  
• Sensor where VREF check failed disconnected.
  
• Disconnect PCM. Inspect for damaged or pushed out pins, corrosion, loose wires, etc. Service as necessary.
  
• Install breakout box, leave PCM disconnected.
  
• Measure resistance between Test Pin 90 (VREF) at the breakout box and the VREF circuit at the appropriate sensor vehicle harness connector.
  

Is resistance less than 5.0 ohms?


Yes


No


REPLACE PCM. REMOVE breakout box. RECONNECT all components. RERUN Quick Test.


SERVICE open VREF circuit. REFER to the EVTM schematic (if available), etc. and DTCs received to help pinpoint the location of the open. REMOVE breakout box. RECONNECT all components. RERUN Quick Test.


C25 CAN THE ECT PID BE ACCESSED?

• Key on, engine off.
  
• Attempt to access the ECT PID.
  

Can the ECT PID be accessed?


Yes


No


GO to C26.


GO to C28.


C26 ARE KOEO DTCs PRESENT FOR TWO OR MORE SENSORS/SWITCHES CONNECTED TO THE SIG RTN CIRCUIT?


Are KOEO DTCs present for two or more sensors/switches connected to the SIG RTN circuit (refer to the EEC-V schematic in Description and Operation)?


Yes


No


GO to C27.


SERVICE open SIG RTN circuit to the sensor where the VREF check failed. RECONNECT all components. RERUN Quick Test.


C27 CHECK SIG RTN CIRCUIT CONTINUITY TO PCM

• Key off.
  
• Scan Tool disconnected.
  
• Sensor where VREF check failed disconnected.
  
• Disconnect PCM. Inspect for damaged or pushed out pins, corrosion, loose wires, etc. Service as necessary.
  
• Install breakout box, leave PCM disconnected.
  
• Measure resistance between the SIG RTN circuit at the appropriate sensor vehicle harness connector and Test Pin 91 (SIG RTN) at the breakout box.
  

Is resistance less than 5.0 ohms?


Yes


No


RECONNECT sensor. GO to C28.


SERVICE open SIG RTN circuit. REFER to the EVTM schematic (if available), etc. and DTCs received to help pinpoint the location of the open. REMOVE breakout box. RECONNECT all components. RERUN Quick Test.


C28 CHECK PCM PWR GND CIRCUITS

• Key off.
  
• Disconnect Scan Tool from DLC.
  
• Breakout box installed, processor disconnected.
  
• Measure resistance between the battery negative post and Test Pins 51, 77 and 103 (PWR GND) at the breakout box.
  

Is each resistance less than 5.0 ohms?


Yes


No


GO to C29.


SERVICE open circuit. REMOVE breakout box. RECONNECT all components. RERUN Quick Test.


C29 CHECK GROUND CIRCUITS IN PCM

• Key off.
  
• Scan Tool disconnected.
  
• Breakout box installed.
  
• Connect PCM to breakout box.
  
• Measure resistance between Test Pin 91 (SIG RTN) and Test Pins 51, 77 and 103 (PWR GND) at the breakout box.
  

Is each resistance less than 5.0 ohms?


Yes


No


SIG RTN/PWR GND circuits are OK in the harness and PCM. VERIFY results of previous test steps. RERUN Quick Test to verify DTC/symptom.


REPLACE PCM. REMOVE breakout box. RECONNECT all components. RERUN Quick Test.


C35 CHECK VREF FOR SHORT TO POWER

• Key off.
  
• Sensor where VREF check failed disconnected.
  
• Disconnect all other sensors connected to VREF (refer to Sensors Connected to VREF chart at beginning of this pinpoint test).
  
• Disconnect PCM. Inspect for damaged or pushed out pins, corrosion, loose wires, etc. Service as necessary.
  
• Leave PCM disconnected.
  
• Key on, engine off.
  
• Measure voltage between the VREF circuit at the TP sensor vehicle harness connector and the battery negative post.
  

Is voltage less than 0.5 volts?


Yes


No


REPLACE PCM. RECONNECT all components. RERUN Quick Test.


SERVICE VREF short to power in harness. RECONNECT all components. RERUN Quick Test.


 



 



A5 CHECK FEPS CIRCUIT FOR SHORT TO POWER

• Key off.
  
• Key on, engine off.
  
• Measure voltage between Pin 13 at the data link connector and battery negative post.
  

Is voltage greater than 9.0 volts?


Yes


No


SERVICE short to power. REMOVE breakout box. RECONNECT all components. RERUN Quick Test.


For 3.4L Taurus SHO:

GO to A17.

All Others:

GO to A6.


A6 CHECK FOR SPARK AT THE PLUGS

• Disconnect the spark plug wire to any accessible cylinder.
  
• Connect spark tester between spark plug wire and engine ground.
  
• Connect Spark Plug Firing Indicator D81P-6666-A or D89P-6666-A or equivalent.
  
• Crank engine and check for spark.
  
• Reconnect the spark plug wire to the spark plug.
  

Was spark present and consistent?


Yes


No


GO to A7.


For 3.0L Windstar:

GO to Pinpoint Test Step JA1.

For 2.0L Probe:

GO to Pinpoint Test Step JK1.

All Others:

GO to Pinpoint Test Step JD1.


A7 CHECK FUEL PRESSURE

• WARNING: BEFORE SERVICING OR REPLACING ANY COMPONENTS IN THE FUEL SYSTEM, REDUCE THE POSSIBILITY OF INJURY OR FIRE BY FOLLOWING DIRECTIONS IN PINPOINT TEST HC WARNING, CAUTION, ANDHANDLING.
  
• Key off.
  
• Release the fuel pressure.
  
• Install fuel pressure tester.
  
• Scan Tool connected.
  
• Key on, engine off.
  
• Enter Output Test Mode (refer to Diagnostic Methods) and run the fuel pump to obtain maximum fuel pressure.
  

Is fuel pressure between 35 and 40 psi (240-280 kPa)?


Yes


No


GO to A8.


For Continental:

GO to Pinpoint Test Step KB45.

All Others:

GO to Pinpoint Test Step HC1.


A8 CHECK FUEL PRESSURE LEAKDOWN

• Observe WARNING, CAUTION ANDHANDLING in Pinpoint Test HC.
  
• Fuel pressure tester installed.
  
• Scan Tool connected.
  
• Key on, engine off.
  
• Enter Output Test Mode and run fuel pump to obtain maximum fuel pressure.
  
• Exit Output Test Mode, key off.
  
• Verify fuel pressure remains within 5 psi of the maximum pressure for 1 minute after turning pump off.
  

Does fuel pressure remain within 5 psi?


Yes


No


GO to A9.


For Continental:

GO to Pinpoint Test Step KB45.

All Others:

GO to Pinpoint Test Step HC1.


A9 CHECK CONTINUITY OF IGNITION GROUND CIRCUIT

• Key off.
  
• Disconnect PCM. Inspect for damaged or pushed out pins, corrosion, loose wires, etc. Service as necessary.
  
• Install breakout box, leave PCM disconnected.
  
• Install EI diagnostic harness (Rotunda 007-00059 or equivalent) to ignition breakout box.
  
• Connect ICM tee to vehicle harness.
  
• Install ICM overlay.
  
• Measure resistance between Test Pin 23 at breakout box and IGN GND circuit pin at the EI diagnostic harness.
  

Is resistance less than 5.0 ohms?


Yes


No


GO to A10.


SERVICE open circuit. REMOVE breakout box. RECONNECT all components. RERUN Quick Test.


A10 CHECK PIP CIRCUIT CONTINUITY

• Key off.
  
• Breakout box installed, PCM disconnected.
  
• EI harness installed, ICM disconnected.
  
• Measure resistance between Test Pin 49 at breakout box and PIP circuit at the EI diagnostic harness.
  

Is resistance less than 5.0 ohms?


Yes


No


GO to A11.


SERVICE open circuit. REMOVE breakout box. RECONNECT all components. RERUN Quick Test.


A11 CHECK PIP CIRCUIT FOR SHORT TO POWER

• Key off.
  
• Breakout box installed, PCM disconnected.
  
• ICM disconnected.
  
• EI harness installed.
  
• Key on, engine off.
  
• Measure voltage between Test Pin 49 at breakout box and battery negative post.
  

Is voltage greater than 1.0 volts?


Yes


No


SERVICE short to power. REMOVE breakout box. RECONNECT all components. RERUN Quick Test.


GO to A12.


A12 CHECK PIP SIGNAL CIRCUIT FOR SHORTS TO GROUND

• Key off.
  
• Breakout box installed, PCM disconnected.
  
• ICM disconnected.
  
• Measure resistance between Test Pin 49 (PIP) and Test Pins 23, 51, 91 and 103 (short to ground).
  

Is each resistance greater than 10,000 ohms?


Yes


No


GO to A13.


SERVICE short circuit. REMOVE breakout box. RECONNECT all components. RERUN Quick Test. If vehicle does not start. GO to A13.


A13 CHECK PIP SIGNAL

• Key off.
  
• Breakout box installed, PCM disconnected.
  
• Reconnect ICM.
  
• Measure voltage between Test Pin 49 and Test Pin 23 at breakout box.
  
• Crank engine, record reading.
  

Is voltage between 3.0 and 7.0 volts?


Yes


No


REPLACE PCM. REMOVE breakout box. RERUN Quick Test.


REPLACE ICM. REMOVE breakout box. RERUN Quick Test.


A15 CHECK FUEL PRESSURE

• Connect Scan Tool to DLC.
  
• Access IPS PID (fuel pressure).
  
• Record fuel pressure.
  
• Connect fuel pressure gauge to schrader valve.
  
• Key on, engine off.
  
• Record fuel pressure.
  

Is fuel pressure between 105 and 130 psi on the Scan Tool and fuel pressure gauge?


Yes


No


GO to A16.


GO to Fuel Systems Pinpoint Test Step HB1.


A16 CHECK INJECTOR SIGNAL FROM NGV MODULE

• Key off.
  
• Install 60 pin breakout box to NGV module, keep NGV module connected.
  
• Connect test lamp between Test Pin 75 and ground.
  
• Crank engine.
  

Does test lamp have a dim glow while cranking?


Yes


No


GO to A6. RECONNECT all components.


No light or continuously bright light. GO to Fuel System Pinpoint Test Step HA47.


A17 CHECK PCM DRIVER TO COILS

• Key off.
  
• Connect PCM breakout box.
  
• Connect incandescent test lamp between B+ and to each coil driver circuit.
  
• Crank engine.
  

Does lamp blink consistently and brightly (one blink per engine revolution)?


Yes


No


REPLACE PCM. REMOVE breakout box. RECONNECT all components. RERUN Quick Test.


GO to Pinpoint Test Step JD4.


A20 IDENTIFY TYPE OF NO START





NOTE


Note: The purpose of this Test Step is to identify intermittent No Starts in order to guide the technician to the proper repairprocedure.




Does the vehicle start now?


Yes


No


Vehicle is an intermittent No Start. GO to Pinpoint Test Step Z50.


GO to A21.


A21 ATTEMPT TO CRANK ENGINE





NOTE


Note: Verify Inertia Fuel Shutoff (IFS) switch is set (button pushed in). Refer to Owner Guide for location.




Does engine crank?


Yes


No


GO to A22.


REFER to Starting/Engine Service Manual Group.


A22 CHECK FOR VREF AT THROTTLE POSITION (TP) SENSOR

• Key off.
  
• Disconnect TP sensor.
  
• Key on, engine off.
  
• Measure voltage between VREF circuit and SIG RTN circuit at the TP sensor vehicle harness connector.
  

Is voltage between 4.0 and 6.0 volts?


Yes


No


RECONNECT TP sensor. GO to A23.


GO to Pinpoint Test Step C1.


A23 CHECK FOR SPARK AT PLUGS

• Disconnect the spark plug wire to any accessible cylinder.
  
• Connect spark tester between spark plug wire and engine ground.
  
• Crank engine and check for spark.
  
• Reconnect the spark plug wire to the spark plug.
  

Was spark present and consistent?


Yes


No


GO to A33.


GO to A24.


A24 CHECK FOR SPARK AT COIL

• Remove high tension coil wire from distributor and install spark tester.
  
• Check for spark while cranking.
  
• Reconnect high tension coil wire to distributor.
  

Was spark present during crank?


Yes


No


GO to Pinpoint Test Step JB12 for ICM, cap, rotor and wire diagnosis.


GO to A25.


A25 CHECK CONTINUITY OF IGN GND CIRCUIT

• Key off.
  
• Disconnect Camshaft Position (CMP) sensor.
  
• Disconnect Powertrain Control Module (PCM) 104 pin connector. Inspect for damaged or pushed out pins, corrosion, loose wires, etc. Service as necessary.
  
• Install breakout box, leave PCM disconnected.
  
• Connect DI diagnostic harness to EEC breakout box, connect B- lead to negative post of battery, connect ICM tee to ICM and vehicle harness, and connect CMP tee to CMP vehicle harness.
  
• Do not connect B+ lead of DI diagnostic harness to battery.
  
• CAUTION: Do not connect PCM to EEC breakout box when it is used with DI diagnostic harness.
  
• Make sure PIP OPEN/NORMAL/SPOUT OPEN switch on DI diagnostic harness is in the NORMAL position.
  
• Use DI overlay on breakout box.
  
• Measure resistance between Test Pin 23 at breakout box and Pin 35 at the DI diagnostic harness (IGN GND circuit).
  

Is resistance less than 5.0 ohms?


Yes


No


GO to A26.


SERVICE open circuit. REMOVE breakout box. RECONNECT all components. RERUN Quick Test.


A26 ISOLATION OF PROBLEM TO SPOUT CIRCUIT

• Reconnect CMP sensor to vehicle harness.
  
• Breakout box installed.
  
• Connect PCM to breakout box.
  
• Timing switch to "DIST" position on breakout box.
  
• Attempt to start vehicle.
  

Does the vehicle start?


Yes


No


Timing switch to "Computed" position on breakout box. GO to A31.


GO to A27.


A27 CHECK SPOUT SIGNAL

• Key on, engine off.
  
• Breakout box installed, PCM connected.
  
• Timing switch to "DIST" position on breakout box.
  
• Crank engine.
  
• Measure AC voltage between Test Pin 50 (SPOUT) at breakout box and battery negative post during crank.
  

Is voltage between 3.0 and 6.0 volts?


Yes


No


EEC system OK. REMOVE breakout box. RECONNECT all components.

GO to Pinpoint Test Step JG1 for DI system diagnosis.


PLACE timing switch to "Computed" position and GO to A28.


A28 CHECK SPOUT AND PIP CIRCUITS FOR SHORT TO POWER

• Key off.
  
• Breakout box installed.
  
• Disconnect PCM.
  
• Disconnect ICM and CMP sensor.
  
• Key on.
  
• Measure voltage between Test Pin 50 (SPOUT) at breakout box and battery negative post.
  
• Measure voltage between Test Pin 49 (PIP) at breakout box and battery negative post.
  

Is voltage greater than 10.5 volts?


Yes


No


SERVICE short circuit to the START circuit or to the VPWR circuit in the harness. REMOVE breakout box. RECONNECT all components. RERUN Quick Test.


GO to A29.


A29 CHECK SPOUT AND PIP CIRCUITS FOR SHORTS TO GROUND

• Key off.
  
• Breakout box installed.
  
• PCM, ICM and CMP sensor disconnected.
  
• Measure resistance between Test Pin 50 (SPOUT) and Test Pins 23, 51, 103 and 91 (short to GROUND) and 49 (short to PIP) at breakout box.
  
• Measure resistance between Test Pin 49 (PIP) and Test Pins 23, 51, 103 and 91 (short to GROUND) at breakout box.
  

Is each resistance greater than 10,000 ohms?


Yes


No


GO to A30.


SERVICE short circuit. REMOVE breakout box. RECONNECT all components. RERUN Quick Test. If vehicle does not start, GO to A30


A30 ISOLATE SHORT(S) IN PCM TO POWER AND GROUND

• Key off.
  
• Breakout box installed.
  
• Reconnect PCM to breakout box.
  
• ICM and CMP sensor disconnected.
  
• Measure resistance between Test Pin 50 (SPOUT) and Test Pins 71 and 97 (short to POWER) and Test Pins 51 and 103 (short to GROUND) at breakout box.
  
• Measure resistance between Test Pin 49 (PIP) and Test Pins 71 and 97 (short to POWER) and Test Pins 51 and 103 (short to GROUND) at breakout box.
  

Is each resistance greater than 500 ohms?


Yes


No


RECONNECT all components. GO to A31.


REPLACE PCM. REMOVE breakout box. RECONNECT all components. RERUN Quick Test.


A31 CHECK PIP SIGNAL

• Key off.
  
• Breakout box installed, PCM connected.
  
• Measure voltage between Test Pin 49 and Test Pin 51 or 103 at breakout box.
  
• Crank engine, record reading.
  

Is voltage between 3.0 and 7.0 volts?


Yes


No


REPLACE PCM. REMOVE breakout box. RECONNECT all components. RERUN Quick Test.


GO to A32.


A32 CHECK CONTINUITY OF PIP CIRCUIT

• Key off.
  
• Breakout box installed.
  
• Disconnect PCM.
  
• ICM and CMP sensor disconnected.
  
• Measure resistance between Test Pin 49 at breakout box and PIP circuit at Pin 15 and Pin 34 at the DI diagnostic harness.
  

Is each resistance less than 5.0 ohms?


Yes


No


REMOVE PCM breakout box. RECONNECT all components.

GO to Pinpoint Test Step JG1for DI system diagnosis.


SERVICE open circuit. REMOVE breakout box. RECONNECT all components. RERUN Quick Test.


A33 SPOUT SIGNAL VERIFICATION

• Key off.
  
• Disconnect PCM. Inspect for damaged or pushed out pins, corrosion, loose wires, etc. Service as necessary.
  
• Install breakout box and connect PCM to breakout box.
  
• Ensure timing switch is in "Computed" position on breakout box.
  
• Measure voltage between Test Pin 50 (SPOUT) and Test Pins 51 and 103 at the breakout box during crank.
  

Is voltage between 3.0 and 6.0 volts?


Yes


No


GO to A34.


GO to A28.


A34 CHECK FUEL PRESSURE

• WARNING: BEFORE SERVICING OR REPLACING ANY COMPONENTS IN THE FUEL SYSTEM, REDUCE THE POSSIBILITY OF INJURY OR FIRE BY FOLLOWING DIRECTIONS IN PINPOINT TEST HC WARNING, CAUTION ANDHANDLING.
  
• Key off.
  
• Release the fuel pressure.
  
• Install fuel pressure tester.
  
• Scan Tool connected.
  
• Key on, engine off.
  
• Enter Output Test Mode (refer to Diagnostic Methods) and run the fuel pump to obtain maximum fuel pressure.
  

Is fuel pressure between 35 and 40 psi (240-280 kPa)?


Yes


No


GO to A35.


GO to Pinpoint Test Step HC1.


A35 CHECK FUEL PRESSURE LEAKDOWN

• Observe WARNING, CAUTION andHANDLING in Pinpoint Test HC.
  
• Fuel pressure tester installed.
  
• Scan Tool connected.
  
• Key on, engine off.
  
• Enter Output Test Mode and run fuel pump to obtain maximum fuel pressure.
  
• Exit Output Test Mode, key off.
  
• Verify fuel pressure remains within 5 psi of the maximum pressure for 1 minute after turning pump off.
  

Does fuel pressure remain within 5 psi?


Yes


No


RETURN to Symptom Flowcharts, Symptom Index.


GO to Pinpoint Test Step HC1.

• Intro