8 fuel lean codes

[stumped]

Hi guys,

I have a 96 Bronco with a 302. I got 8 lean codes including:

P0133,135,141,155,171,174, P1130,31. My mechanic said to replace the MAF sensor and both oxygen sensors. I do so but still have a check engine light. I am not sure if they are the same codes reappearing as I do not have a scan tool. I just disconnected the battery for a while to hopefully reset the codes. Any ideas?

Terry

 

[BroncoJoe19]

Did you check fuse E in the engine compartment?

Also give her a good check for vacuum leaks. The vacuum leaks could give you lean codes.

 

[miesk5]

yo

Most replace the O2 Sensor; but ck for wiring/connector/harness damage and other likely and no $ parts replacement check; incl testing the sensor ckt; fuses, heater ckt, etc. Fords naming convention is that bank one is the same bank as where the number one cylinder is sensor one is before the cat sensor two is after the cat.

Here is da skinny from Ford on the DTCs

DRIVEABILITY - HO2S (HEATED OXYGEN SENSOR), CATALYST, AND FUEL SYSTEM MONITORS - SERVICE TIPS - OBD II VEHICLES ONLY - 96 Bronco, TSB 01-9-7 Source: by Ford via v8sho.com

And here is what my buddy Joe refers to for Fuse E (In 96, it is fuse 5 in Engine compartment's Power Distribution Box, next to air filter assy), Altho this is for earlier years, it may apply and is a no $ check/repair:

Fuse E Blown, Short Circuits, Common Locations TSB 95-02-11 for 94-95 Bronco & Trucks; HO2S Failure in TSB 95-2-11 for 92-95 Bronco & F Series; "the HO2S wires in the 12A690 (subassembly of the 14B060 battery cable) harness may be cut on the lower right engine mount causing improper signals to be sent to the PCM. Damage may be under the electrical tape..." SEE MORE ON REPAIR Source: by Ford via Chilton

Miesk5 Note; also see TSB 95-5-21 which is more detailed;

Fuse "E" Inoperative, ABS Light On, Back-Up Lamps Inoperative, DRLs Inoperative, MIL On, Inadvertent Self-Test, Speedometer Inoperative & Trailer Battery Charge Relay Inoperative in TSB 95-5-21 for 92-95 Bronco & F Series; "...the HO2S wires in the 12A690 (subassembly of the 14B060 battery cable) harness may become chafed and the vehicle could exhibit any one of the following conditions....Lack of proper HEGO operation may cause, or be the result of a rich or lean fuel condition, which could cause additional heat in the catalyst. Perform self test KOEO and KOER, service any codes. CHECK FOR PROPER HEGO GROUND. If the HEGO ground is good, the following areas may be at fault: ..." READ MORE

Source: by Ford via Steve83 (Steve, That dirty old truck) at SuperMotors.net



TSB 95-5-21 Fuse "E" Inoperative - ABS Light On - Back-Up Lamps Inoperative - DRLs Inoperative - MIL On - Speedometer Inoperative Publication Date: MARCH 13, 1995 LIGHT TRUCK: 1992-1995 BRONCO, F-150-350 SERIESISSUE: On some vehicles the HO2S wires in the 12A690 (subassembly of the 14B060 battery cable) harness may become chafed and the vehicle could exhibit any one of the following conditions:

ABS light on

Speedometer inoperative

Back-up lamps inoperative

Daytime running lamps inoperative

Trailer battery charge relay inoperative

MIL on, displaying Codes: 172, 173 or 41 for HO2S failure

Inadvertent PCM Self-Test

ACTION: Replace the damaged wire harness and HO2S sensor. Refer to the following procedure for service details.

SERVICE PROCEDURE:

1. Disconnect negative battery cable.

2. Disconnect the solenoid terminal and positive battery cable from the starter.

3. Pull the cable downward to inspect the 12A690 harness for chafing, pinholes, etc. If necessary, remove the convolute and tape from the 12A690 harness located next to the lower RH side engine mount.

4. If the 12A690 harness is damaged, replace the 14B060 assembly (F5TZ-14300-EA) and the HO2S sensor (F4UZ-9F472-A).

5. Inspect Fuse "E" and replace if necessary (D9ZZ-14526-D).

6. Clear all codes stored in memory.

7. Retest and verify the concern has been resolved.

PART NUMBER - PART NAME

D9ZZ-14526-D Fuse - 15 Amp

F5TZ-14300-EA Harness Assembly

F4UZ-9F472-A HO2S Sensor

OTHER APPLICABLE ARTICLES: NONE

WARRANTY STATUS: Eligible Under The Provisions Of Bumper To Bumper Warranty Coverage

OPERATION - DESCRIPTION - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - TIME

950521A - - - - - Replace Harness Assembly, HO2S Sensor And Fuse "E" (If Overloaded) - 0.7 Hr.

=

GL!

 

[stumped]

Did you check fuse E in the engine compartment?

Also give her a good check for vacuum leaks. The vacuum leaks could give you lean codes.

Thanks, I will try that 1st ....

 

[stumped]

yo

Most replace the O2 Sensor; but ck for wiring/connector/harness damage and other likely and no $ parts replacement check; incl testing the sensor ckt; fuses, heater ckt, etc. Fords naming convention is that bank one is the same bank as where the number one cylinder is sensor one is before the cat sensor two is after the cat.

Here is da skinny from Ford on the DTCs

DRIVEABILITY - HO2S (HEATED OXYGEN SENSOR), CATALYST, AND FUEL SYSTEM MONITORS - SERVICE TIPS - OBD II VEHICLES ONLY - 96 Bronco, TSB 01-9-7 Source: by Ford via v8sho.com

And here is what my buddy Joe refers to for Fuse E (In 96, it is fuse 5 in Engine compartment's Power Distribution Box, next to air filter assy), Altho this is for earlier years, it may apply and is a no $ check/repair:

Fuse E Blown, Short Circuits, Common Locations TSB 95-02-11 for 94-95 Bronco & Trucks; HO2S Failure in TSB 95-2-11 for 92-95 Bronco & F Series; "the HO2S wires in the 12A690 (subassembly of the 14B060 battery cable) harness may be cut on the lower right engine mount causing improper signals to be sent to the PCM. Damage may be under the electrical tape..." SEE MORE ON REPAIR Source: by Ford via Chilton

Miesk5 Note; also see TSB 95-5-21 which is more detailed;

Fuse "E" Inoperative, ABS Light On, Back-Up Lamps Inoperative, DRLs Inoperative, MIL On, Inadvertent Self-Test, Speedometer Inoperative & Trailer Battery Charge Relay Inoperative in TSB 95-5-21 for 92-95 Bronco & F Series; "...the HO2S wires in the 12A690 (subassembly of the 14B060 battery cable) harness may become chafed and the vehicle could exhibit any one of the following conditions....Lack of proper HEGO operation may cause, or be the result of a rich or lean fuel condition, which could cause additional heat in the catalyst. Perform self test KOEO and KOER, service any codes. CHECK FOR PROPER HEGO GROUND. If the HEGO ground is good, the following areas may be at fault: ..." READ MORE

Source: by Ford via Steve83 (Steve, That dirty old truck) at SuperMotors.net



TSB 95-5-21 Fuse "E" Inoperative - ABS Light On - Back-Up Lamps Inoperative - DRLs Inoperative - MIL On - Speedometer Inoperative Publication Date: MARCH 13, 1995 LIGHT TRUCK: 1992-1995 BRONCO, F-150-350 SERIESISSUE: On some vehicles the HO2S wires in the 12A690 (subassembly of the 14B060 battery cable) harness may become chafed and the vehicle could exhibit any one of the following conditions:

ABS light on

Speedometer inoperative

Back-up lamps inoperative

Daytime running lamps inoperative

Trailer battery charge relay inoperative

MIL on, displaying Codes: 172, 173 or 41 for HO2S failure

Inadvertent PCM Self-Test

ACTION: Replace the damaged wire harness and HO2S sensor. Refer to the following procedure for service details.

SERVICE PROCEDURE:

1. Disconnect negative battery cable.

2. Disconnect the solenoid terminal and positive battery cable from the starter.

3. Pull the cable downward to inspect the 12A690 harness for chafing, pinholes, etc. If necessary, remove the convolute and tape from the 12A690 harness located next to the lower RH side engine mount.

4. If the 12A690 harness is damaged, replace the 14B060 assembly (F5TZ-14300-EA) and the HO2S sensor (F4UZ-9F472-A).

5. Inspect Fuse "E" and replace if necessary (D9ZZ-14526-D).

6. Clear all codes stored in memory.

7. Retest and verify the concern has been resolved.

PART NUMBER - PART NAME

D9ZZ-14526-D Fuse - 15 Amp

F5TZ-14300-EA Harness Assembly

F4UZ-9F472-A HO2S Sensor

OTHER APPLICABLE ARTICLES: NONE

WARRANTY STATUS: Eligible Under The Provisions Of Bumper To Bumper Warranty Coverage

OPERATION - DESCRIPTION - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - TIME

950521A - - - - - Replace Harness Assembly, HO2S Sensor And Fuse "E" (If Overloaded) - 0.7 Hr.

=

GL!

Thanks, I will give it a go ...

 

[billyo1]

Hi guys,

I have a 96 Bronco with a 302. I got 8 lean codes including:

P0133,135,141,155,171,174, P1130,31. My mechanic said to replace the MAF sensor and both oxygen sensors. I do so but still have a check engine light. I am not sure if they are the same codes reappearing as I do not have a scan tool. I just disconnected the battery for a while to hopefully reset the codes. Any ideas?

Terry

fuel pressure regulator is another possibility

 

[miesk5]

yo BVill,

Best thing to do was to post this in a new thread here; but since I'm awake now.

DTC P0133 - HO2S Sensor Circuit Slow Response (HO2S-11) The HO2S monitor checks the HO2S sensor frequency and amplitude. If during testing, the frequency and amplitude were to fall below a calibrated limit, the code will set;

Possible Causes: Electrical:

· Shorted/open wiring

· PCM Induction System:

· MAF sensor (On 4-cylinder engines, if P0133 is present, this could be caused by a MAF issue - on 6- and 8-cylinder engines, this could only be a MAF issue if P0133 and P0153 are both present)

· Inlet air leaks (unmetered air)

Fuel Concerns: · Poor fuel quality Base Engine:

· Exhaust leaks (upstream or near HO2S) HO2S Concerns:

· Contaminated HO2S sensor (contamination from the use of silicone-based cleaners and sealants, leaded fuel, excessive oil consumption - Deteriorating HO2S sensor; OBD II Response Rate Monitor: The OBD II Response Rate Monitor (P0133/P0153) is only run at vehicle speeds between approximately 50-95 km/h (30-60 mph), during steady-state conditions. The test lasts approximately 6 seconds. Therefore, P0133/P0153 cannot be diagnosed at idle in the repair bay...

Most replace the O2 Sensor; but ck for wiring/connector/harness damage and other likely and no $ parts replacement checks 1st; incl testing the sensor ckt; fuses, heater ckt, etc.

Fords naming convention is that bank one is the same bank as where the number one cylinder is; sensor one is before the cat sensor two is after the cat.

DTC P0135 - HO2S Sensor Circuit Malfunction (HO2S-11)';"... During testing the HO2S Heaters are checked for opens/shorts and excessive current draw. The test fails when current draw exceeds a calibrated limit and/or an open or short is detected. Short to VPWR in harness or HO2S. Water in harness connector. Open VPWR circuit. Open GND circuit. Low battery voltage. Corrosion or poor mating terminals and wiring Damaged HO2S heater. Damaged PCM. wiring. Damaged HO2S heater. Damaged PCM..."

Source: by slingblade

DTC P0135, P0141, P0155 AND P0161: HO2S HEATER SIGNAL CIRCUIT IS OPEN, SHORTED TO GROUND, SHORTED TO B+ OR EXCESSIVE CURRENT DRAW; POssible Causes & Troubleshooting

Source: by Fishallot & 96broncoman

Possible causes:

-- Shorts to B+ in harness or HO2S.

-- Water in connectors.

-- Cut or pulled wires.

-- Disconnected wiring.

-- Open VPWR circuit.

-- Open GND circuit.

-- Low battery voltage.

-- Corrosion or poor mating terminals.

-- Damaged PCM.

l Visually inspect the HO2S circuit for exposed wiring, contamination, corrosion and proper assembly.

Im going to type the mitchell stuff word for word in bold. I will start where i started my process.

32) Check for voltage at HO2S Heater wiring harness connector. Turn ignition off. Disconnect suspect HO2S. Inspect wiring harness for damage and repair as necessary. Turn ignition on. Measure voltage between SIG RTN and VPWR terminal at HO2S wiring harness connector. If voltage is 10.5 volts or less, go to next step. If voltage is more than 10.5 volts, go to step 34) I went to step 34.

34)Turn ignition off. With Suspect sensor disconnected, measure resistance between HO2S HEATER GND terminal adn VPWR terminal at HO2S wiring harness connector. If resistance is 3-30 ohms, go to next step, If resistance is not 3-30 ohms, replace HO2S sensor and repeat. I continued to the next step.

35)Leave ignition off and suspect sensor disconnected. Measure resistance between HO2S HEATER GND terminal at HO2S wiring harness connector and HO2S case. Measure resistance between HO2S HEATER GND terminal and SIG RTN terminall at HO2S wiring harness connector. Measure resistance between VPWR terminal at HO2S wiring harness connector and HO2S case. If each resistance measurement is more than 10,000 ohms, go to next step. If any resistance is 10,000 or less, replace HO2S and repeat. Thats the step where I metered all open lines, but i may have metered the wrong side of the HO2S wiring harness. The next step is the tricky one i was referring to:

36)Check for short circuit. Leave igniton off and sensor disconnected. Disconnect scan tester from DLC (if applicable). Disconnect PCM 104-pin connector. Inspect connector for damage and replace is necessary. Install EEC-V breakout box (014-009050), leaving pcm disconnected. Measure resistance between suspect sensor and test pins indicated as follows:

i will only type out the procedure for the code i am throwing

DTC P0155 (LR), Test pin No. 94 and test pins No. 24, 76, 91, 97, and 103. If resistance is more than 10,000 ohms, go to next step. If resistance is 10,000 ohms or less, repair short in circuit and repeat.

Bank 1, Sensor 2 (passenger side between cats (or behind the second one in a California vehicle)

DTC P0171 - System to Lean (Bank 1); "... The Adaptive Fuel Strategy continuously monitors fuel delivery hardware. The test fails when the adaptive fuel tables reach a rich calibrated limit. For lean and rich DTCs: Fuel system Excessive fuel pressure. Leaking/contaminated fuel injectors. Leaking fuel pressure regulator. Low fuel pressure or running out of fuel. Vapor recovery system. Induction system: Air leaks after the MAF. Vacuum Leaks. PCV system. Improperly seated engine oil dipstick. EGR system: Leaking gasket. Stuck EGR valve. Leaking diaphragm or EVR. Base Engine: Oil overfill. Cam timing. Cylinder compression. Exhaust leaks before or near the HO2Ss ..."

Source: by slingblade

DTC P0174 - System to Lean (Bank 2); "... The Adaptive Fuel Strategy continuously monitors the fuel delivery hardware. The test fails when the adaptive fuel tables reach a rich calibrated limit. See Possible Causes for DTC P0171 ..."

Source: by slingblade

DTC P0174; "...Basically this means that an oxygen sensor in bank 2 detected a lean condition (too much oxygen in the exhaust). On V6/V8/V10 engines, Bank 2 is generally the side of the engine that doesn't have cylinder #1 (driver's side); The MAF (Mass Air Flow) Sensor is dirty or faulty. Note: The use of "oiled" air filters can cause the MAF to become dirty if the filter is over-oiled. There could be a vacuum leak downstream of the MAF sensor..." READ MORE

Source: by obd-codes.com

P1130 - Lack of HO2S-11 Switch, Fuel Trim at Limit The HEGO Sensor is monitored for switching. The test fails when the HO2S fails to switch due to circuit or fuel at or exceeding a calibrated limit. Electrical:

Short to VPWR in harness or HO2S

Water in harness connector

Open/Shorted HO2S circuit

Corrosion or poor mating terminals and wiring

Damaged HO2S

Damaged PCM

Fuel System:

Excessive fuel pressure

Leaking/contaminated fuel injectors

Leaking fuel pressure regulator

Low fuel pressure or running out of fuel

Vapor recovery system

Induction System:

Air leaks after the MAF

Vacuum Leaks

PCV system

Improperly seated engine oil dipstick

EGR System:

Leaking gasket

Stuck EGR valve

Leaking diaphragm or EVR

Base Engine:

Oil overfill

Cam timing

Cylinder compression

Exhaust leaks before or near the HO2S(s)

A fuel control HO2S PID switching across 0.45 volt from 0.2 to 0.9 volt indicates a normal switching HO2S.

P1131 - Lack of HO2S-11 Switch, Sensor Indicates Lean A HEGO sensor indicating lean at the end of a test is trying to correct for an over-rich condition. The test fails when the fuel control system no longer detects switching for a calibrated amount of time. See Possible Causes for DTC P1130

Source(s); DRIVEABILITY - HO2S (HEATED OXYGEN SENSOR), CATALYST, AND FUEL SYSTEM MONITORS - SERVICE TIPS - OBD II VEHICLES ONLY - 96 Bronco, TSB 01-9-7 Source: by Ford via Chilton