DTC Troubleshooting: P0135 (41)

DTC P0135:  A/F Sensor (Sensor 1) Heater Circuit Malfunction

1.Turn the ignition switch ON (II).

2.Clear the DTC with the HDS.

3.Start the engine. Hold the engine speed at 3,000 rpm (min-1) without load (in Park or neutral) until the radiator fan comes on, then let it idle.

4.Check for Temporary DTCs or DTCs with the HDS.

Is DTC P0135 indicated?


YES - Go to 5.


NO - Intermittent failure, system is OK at this time. Check for poor connections or loose terminals at the A/F sensor (Sensor 1), the A/F sensor relay and the ECM/PCM.n


5.Turn the ignition switch OFF.

6.Check the following fuses:
  • LAF (A/F SENSOR) (20 A) fuse in under-hood subfuse/relay box A.
  • No. 6 IG1 P/W RELAY (7.5 A) fuse in under-dash fuse/relay box.

Are any of the fuses blown?


YES - Repair short in the wire between the A/F sensor relay and the fuses, then go to 25.


NO - Go to 7.

7.Disconnect the A/F sensor (Sensor 1) 4P connector.

8.At A/F sensor side, measure resistance between A/F sensor (Sensor 1) 4P connector terminals No. 3 and No. 4.

 

Is there 2.1-2.9 W at room temperature?


YES - Go to 9.


NO - Go to 24.


9.At A/F sensor side, check for continuity between A/F sensor (Sensor 1) 4P connector terminal No. 2 and A/F sensor (Sensor 1) 4P connector terminals No. 3 and No. 4 individually.

 

Is there continuity?


YES - Go to 24.


NO - Go to 10.

10.Jump the SCS line with the HDS.

11.Disconnect ECM/PCM connector A (31P).

12.Check for continuity between ECM/PCM connector terminal A10 and body ground.

 

Is there continuity?


YES - Repair short in the wire between the ECM/PCM (A10) and the A/F sensor (Sensor 1), then go to 25.


NO - Go to 13.


13.Connect the A/F sensor (Sensor 1) 4P connector terminal No. 4 to body ground with a jumper wire.

 

14.Check for continuity between ECM/PCM connector terminal A10 and body ground.

 

Is there continuity?


YES - Go to 15.


NO - Repair open in the wire between the ECM/PCM (A10) and the A/F sensor (Sensor 1), then go to 25.


15.Remove the A/F sensor relay (A).

 

16.Check the A/F sensor relay.

Is the A/F sensor relay OK?


YES - Go to 17.


NO - Replace the A/F sensor relay, then go to 25.

17.Connect A/F sensor (Sensor 1) 4P connector terminal No. 3 to body ground with a jumper wire.

 

18.Check for continuity between A/F sensor relay terminal No. 2 and body ground.

 

Is there continuity?


YES - Go to 19.


NO - Repair open in the wire between the A/F sensor (Sensor 1) and the A/F sensor relay, then go to 25.


19.Disconnect ECM/PCM connector E (31P).

20.Check for continuity between ECM/PCM connector terminal E8 and the A/F sensor relay terminal No. 3.

 

Is there continuity?


YES - Go to 21.


NO - Repair open in the wire between the ECM/PCM (E8) and the A/F sensor relay, then go to 25.


21.Measure voltage between A/F sensor relay terminal No. 1 and body ground.

 

Is there battery voltage?


YES - Go to 22.


NO - Repair open in the wire between the A/F sensor relay and LAF (A/F SENSOR) (20 A) fuse, or the LAF (A/F SENSOR) (20 A) fuse and No. 2 ENG (30 A) fuse, then go to 25.


22.Turn the iguition switch ON (II).

23.Measuer voltage between A/F sensor relay terminal No. 4 and body ground.

 

Is there battery voltage?


YES - Go to 31.


NO - Repair open in the wire between the A/F sensor relay and No. 6 P/W RELAY (7.5 A) fuse, then go to 25.


24.Replace the A/F sensor (Sensor 1).

25.Reconnect all connectors.

26.Turn the ignition switch ON (II).

27.Reset the ECM/PCM with the HDS.

28.Do the ECM/PCM idle learn procedure.

29.Check for Temporary DTCs or DTCs with the HDS.

Are any Temporary DTCs or DTCs indicated?


YES - If DTC P0135 is indicated, check for poor connections or loose terminals at the A/F sensor (Sensor 1) and the ECM/PCM, then go to 1. If any other Temporary DTCs or DTCs are indicated, go to the indicated DTC's troubleshooting.


NO - Go to 30.

30.Monitor the OBD STATUS for DTC P0135 in the DTCs MENU with the HDS.

Does the screen indicate PASSED?


YES - Troubleshooting is complete.n


NO - If the screen indicates FAILED, check for poor connections or loose terminals at the A/F sensor (Sensor 1) and the ECM/PCM, then go to 1. If the screen indicates NOT COMPLETED, go to 27 and recheck.


31.Update the ECM/PCM if it does not have the latest software, or substitute a known-good ECM/PCM.

32.Check for Temporary DTCs or DTCs with the HDS.

Are any Temporary DTCs or DTCs indicated?


YES - If DTC P0135 is indicated, check for poor connections or loose terminals at the A/F sensor (Sensor 1), and the A/F sensor relay and the ECM/PCM, then go to 1. If any other Temporary DTCs or DTCs are indicated, go to the indicated DTC's troubleshooting.


NO - If the ECM/PCM was updated, troubleshooting is complete. If the ECM/PCM was substituted, replace the original ECM/PCM.n