OBD II CODE TEST

[miesk5]

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.