DTC P0136 [YF (2.0L Zetec)]

DTC P0136	HO2S (Rear) circuit slow response
DETECTION CONDITION	• The PCM monitors input voltage form HO2S-12 continuously. If the maximum or minimum input voltage exceeds calibrated range, the PCM determines HO2S-12 sensor circuit is malfunction.
POSSIBLE CAUSE	• Pinched, shorted, and corroded wiring and pins • Crossed sensor wires • Exhaust leaks • Contaminated or damaged sensor

DTC P0136

HO2S (Rear) circuit slow response

DETECTION CONDITION

• The PCM monitors input voltage form HO2S-12 continuously. If the maximum or minimum input voltage exceeds calibrated range, the PCM determines HO2S-12 sensor circuit is malfunction.

POSSIBLE CAUSE

• Pinched, shorted, and corroded wiring and pins

• Crossed sensor wires

• Exhaust leaks

• Contaminated or damaged sensor

STEP	INSPECTION	ACTION
1	VERIFY FREEZE FRAME DATA HAS BEEN RECORDED • Has FREEZE FRAME DATA been recorded?	Yes	Go to the next step.
No	Record the FREEZE FRAME DATA on the repair order, then go to the next step.
2	VERIFY REPAIR INFORMATION AVAILABILITY • Verify related service repair information availability. • Is any related repair information available?	Yes	Perform repair or diagnosis according to the available repair information. If the vehicle is not repaired, go to the next step.
No	Go to the next step.
3	INDETIFY TRIGGER DTC FOR FREEZE FRAME DATA • Is DTC P0136 on FREEZE FRAME DATA?	Yes	Go to the next step.
No	Go to FREEZE FRAME DATA DTC inspection. (See DTC TABLE [YF (2.0L Zetec)].)
4	VISUALLY INSPECT FOR HO2S-12 Note • Refer to the PCM connector pin number in the beginning of this pinpoint test. • If necessary to address all Continuous Memory Ignition and Misfire DTCs, if received during Continuous Memory testing, before addressing any KOER HO2S-12 • Visually inspect for HO2S-12 followings: ― Pinched, shorted and corroded wiring and pins ― Crossed sensor wires ― Exhaust leakage ― Contaminated or damaged sensor • Were any concerns found during inspection?	Yes	Repair or replace for malfunctioning part, then go to Step 13.
No	Go to the next step.
5	CHECK FOR KOER DTCS P1137 AND P1138 • Connect the WDS or equivalent to DLC-2. • Start the engine. • Engine at 2,000 rpm for 3 minutes. • Activate KOER self test. • Check for DTCs. • Is DTC P1137 or P1138 present?	Yes	Go to the next step.
No	Intermittent malfunction exist, go to the Step 13.
6	CHECK EXHAUST SYSTEM FOR LEAKS Note • Any exhaust leaks between the engine and the end of the catalyst can cause DTC P0136. • Place vehicle on a host, transaxle in P position, parking brake applied, raise vehicle. • Inspect the following: ― Exhaust flanges for leaks ― HO2S-12 tightening torque ― Check for punctures and cracks in catalyst and pipes leading to them. • Is an exhaust leak present?	Yes	Repair or replace malfunctioning part, then go to Step 13.
No	Go to the next step.
7	CHECK HO2S-12 HARNESS CIRCUIT FOR SHORT TO VPWR AND GROND • Disconnect PCM and HO2S-12. • Measure the resistance between following terminals at PCM harness side connector. ― Between terminal 35 and 91 ― Between terminal 35 and 90 ― Between terminal 35 and 71, 97 ― Between terminal 35 and 24, 51, 76, 103 • Is the resistance greater than 10,000 ohms?	Yes	Go to the next step.
No	Repair for short circuit, then go to Step 13.
8	CHECK HO2S-12 SIGNAL CIRCUIT AND HO2S-12 SIGNAL RETURN CIRCUITS FOR OPEN IN HARNESS • Measure resistance following at harness side connector. ― Between HO2S-12 terminal 1 and PCM terminal 71, 97 ― Between HO2S-12 terminal 4 and PCM terminal 35 ― Between HO2S-12 terminal 3 and PCM terminal 91 • Is the resistance less than 5.0 ohms?	Yes	Go to the next step.
No	Repair for open circuit, then go to Step 13.
9	CHECK HO2S-12 CIRCUIT VOLTAGE • Connect PCM and HO2S-12. • Connect the WDS or equivalent to DLC-2. • Turn the ignition switch to ON. • Access O2S12 PID. • Is the voltage greater than 1.5 V?	Yes	Go to Step 12
No	Go to the next step.
10	CHECK HO2S-12 GND CIRCUIT IN PCM • Disconnect PCM. • Measure the resistance between terminal 91 and 24, 51, 76, 103 at PCM connector. • Is the resistance less than 5.0 ohms?	Yes	Go to the next step.
No	Replace PCM, then go to Step 13.
11	HO2S-12 CIRCUIT CHECK • Connect PCM. • HO2S-12 disconnected. • Jumper terminal 1 and 4 at HO2S-12 harness side connector. • Turn the ignition switch to ON. • Access O2S12 PID. • Is the O2S12 PID value greater than 1.5 V?	Yes	Replace HO2S-12, then go to Step 13.
No	Replace PCM, then go to Step 13.
12	CHECK FOR OVER VOLTAGE ON HO2S-12 CIRCUIT IN PCM • Turn the ignition switch to ON. • HO2S-12 disconnected. • Measure voltage for following: ― Between terminal 3 at HO2S-12 harness side connector and battery negative post. ― Between terminal 4 at HO2S-12 harness side connector and battery negative post. • Is the voltage greater than 1.5 V?	Yes	Replace PCM, then go to the next step.
No	Replace HO2S-12, then go to the next step.
13	VERIFY TROUBLESHOOTING OF DTC P0136 COMPLETED • Make sure to reconnect all disconnected connectors. • Clear the DTC from the PCM memory using the WDS or equivalent. • Cruise the vehicle at 64 km/h {40 MPH} for at least 5 minutes. • Is the PENDING CODE same DTC present?	Yes	Replace PCM, then go to the next step. (See PCM REMOVAL/INSTALLATION [YF (2.0L Zetec)].)
No	Go to the next step.
14	VERIFY AFTER REPAIR PROCEDURE • Perform “After Repair Procedure”. (See AFTER REPAIR PROCEDURE [YF (2.0L Zetec)].) • Is there any DTC present?	Yes	Go to the applicable DTC inspection. (See DTC TABLE [YF (2.0L Zetec)].)
No	Troubleshooting completed.

STEP

INSPECTION

ACTION

VERIFY FREEZE FRAME DATA HAS BEEN RECORDED

• Has FREEZE FRAME DATA been recorded?

Yes

Go to the next step.

Record the FREEZE FRAME DATA on the repair order, then go to the next step.

VERIFY REPAIR INFORMATION AVAILABILITY

• Verify related service repair information availability.

• Is any related repair information available?

Yes

Perform repair or diagnosis according to the available repair information.

If the vehicle is not repaired, go to the next step.

Go to the next step.

INDETIFY TRIGGER DTC FOR FREEZE FRAME DATA

• Is DTC P0136 on FREEZE FRAME DATA?

Yes

Go to the next step.

Go to FREEZE FRAME DATA DTC inspection.

(See DTC TABLE [YF (2.0L Zetec)].)

VISUALLY INSPECT FOR HO2S-12

Note

• Refer to the PCM connector pin number in the beginning of this pinpoint test.

• If necessary to address all Continuous Memory Ignition and Misfire DTCs, if received during Continuous Memory testing, before addressing any KOER HO2S-12

• Visually inspect for HO2S-12 followings:

― Pinched, shorted and corroded wiring and pins

― Crossed sensor wires

― Exhaust leakage

― Contaminated or damaged sensor

• Were any concerns found during inspection?

Yes

Repair or replace for malfunctioning part, then go to Step 13.

Go to the next step.

CHECK FOR KOER DTCS P1137 AND P1138

• Connect the WDS or equivalent to DLC-2.

• Start the engine.

• Engine at 2,000 rpm for 3 minutes.

• Activate KOER self test.

• Check for DTCs.

• Is DTC P1137 or P1138 present?

Yes

Go to the next step.

Intermittent malfunction exist, go to the Step 13.

CHECK EXHAUST SYSTEM FOR LEAKS

Note

• Any exhaust leaks between the engine and the end of the catalyst can cause DTC P0136.

• Place vehicle on a host, transaxle in P position, parking brake applied, raise vehicle.

• Inspect the following:

― Exhaust flanges for leaks

― HO2S-12 tightening torque

― Check for punctures and cracks in catalyst and pipes leading to them.

• Is an exhaust leak present?

Yes

Repair or replace malfunctioning part, then go to Step 13.

Go to the next step.

CHECK HO2S-12 HARNESS CIRCUIT FOR SHORT TO VPWR AND GROND

• Disconnect PCM and HO2S-12.

• Measure the resistance between following terminals at PCM harness side connector.

― Between terminal 35 and 91

― Between terminal 35 and 90

― Between terminal 35 and 71, 97

― Between terminal 35 and 24, 51, 76, 103

• Is the resistance greater than 10,000 ohms?

Yes

Go to the next step.

Repair for short circuit, then go to Step 13.

CHECK HO2S-12 SIGNAL CIRCUIT AND HO2S-12 SIGNAL RETURN CIRCUITS FOR OPEN IN HARNESS

• Measure resistance following at harness side connector.

― Between HO2S-12 terminal 1 and PCM terminal 71, 97

― Between HO2S-12 terminal 4 and PCM terminal 35

― Between HO2S-12 terminal 3 and PCM terminal 91

• Is the resistance less than 5.0 ohms?

Yes

Go to the next step.

Repair for open circuit, then go to Step 13.

CHECK HO2S-12 CIRCUIT VOLTAGE

• Connect PCM and HO2S-12.

• Connect the WDS or equivalent to DLC-2.

• Turn the ignition switch to ON.

• Access O2S12 PID.

• Is the voltage greater than 1.5 V?

Yes

Go to Step 12

Go to the next step.

CHECK HO2S-12 GND CIRCUIT IN PCM

• Disconnect PCM.

• Measure the resistance between terminal 91 and 24, 51, 76, 103 at PCM connector.

• Is the resistance less than 5.0 ohms?

Yes

Go to the next step.

Replace PCM, then go to Step 13.

HO2S-12 CIRCUIT CHECK

• Connect PCM.

• HO2S-12 disconnected.

• Jumper terminal 1 and 4 at HO2S-12 harness side connector.

• Turn the ignition switch to ON.

• Access O2S12 PID.

• Is the O2S12 PID value greater than 1.5 V?

Yes

Replace HO2S-12, then go to Step 13.

Replace PCM, then go to Step 13.

CHECK FOR OVER VOLTAGE ON HO2S-12 CIRCUIT IN PCM

• Turn the ignition switch to ON.

• HO2S-12 disconnected.

• Measure voltage for following:

― Between terminal 3 at HO2S-12 harness side connector and battery negative post.

― Between terminal 4 at HO2S-12 harness side connector and battery negative post.

• Is the voltage greater than 1.5 V?

Yes

Replace PCM, then go to the next step.

Replace HO2S-12, then go to the next step.

VERIFY TROUBLESHOOTING OF DTC P0136 COMPLETED

• Make sure to reconnect all disconnected connectors.

• Clear the DTC from the PCM memory using the WDS or equivalent.

• Cruise the vehicle at 64 km/h {40 MPH} for at least 5 minutes.

• Is the PENDING CODE same DTC present?

Yes

Replace PCM, then go to the next step.

(See PCM REMOVAL/INSTALLATION [YF (2.0L Zetec)].)

Go to the next step.

VERIFY AFTER REPAIR PROCEDURE

• Perform “After Repair Procedure”.

(See AFTER REPAIR PROCEDURE [YF (2.0L Zetec)].)

• Is there any DTC present?

Yes

Go to the applicable DTC inspection.

(See DTC TABLE [YF (2.0L Zetec)].)

Troubleshooting completed.