P0137

DTC P0137: Rear Secondary HO2S (Bank 1, Sensor 2) Circuit Low Voltage

DTC P0157: Front Secondary HO2S (Bank 2, Sensor 2) Circuit Low Voltage

NOTE:
- Before you troubleshoot, record all freeze data and any on-board snapshot, and review the general troubleshooting information.
- Information marked with an asterisk (*) applies to the front bank (Bank 2).

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 without load (in Park or neutral) until the radiator fan comes on, then let it idle.
4. Check the HO2S S2 in the DATA LIST with the HDS.

Does the voltage stay at 0.29 V or less?

YES - Go to step 5.

NO - Intermittent failure, system is OK at this time. Check for poor connections or loose terminals at the secondary HO2S (Sensor 2) and the PCM.

5. Turn the ignition switch OFF.
6. Disconnect the secondary HO2S (Sensor 2) 4P connector.
7. Turn the ignition switch ON (II).
8. Check the HO2S S2 in the DATA LIST with the HDS.

Does the voltage stay at 0.29 V or less?

YES - Go to step 9.

NO - Go to step 13.

9. Turn the ignition switch OFF.
10. Jump the SCS line with the HDS.
11. Disconnect PCM connector B (24P).




12. Check for continuity between secondary HO2S (Sensor 2) 4P connector terminal No.1 and body ground.

Is there continuity?

YES - Repair short in the wire between the PCM (B9 (B18)*) and the secondary HO2S (Sensor 2), then go to step 15.

NO - Go to step 23.

13. Turn the ignition switch OFF.
14. Replace the secondary HO2S (Sensor 2).
15. Reconnect all connectors.
16. Turn the ignition switch ON (II).
17. Reset the PCM with the HDS.
18. Do the PCM idle learn procedure.
19. Start the engine. Hold the engine speed at 3,000 rpm without load (in Park or neutral) until the radiator fan comes on, then let it idle.
20. Test-drive under these conditions:
- ECT SENSOR 1 above 176 degrees F (80 degrees C)
- Transmission in D position
- Engine speed at 1,500 - 3,000 rpm
- Drive 1 minute or more

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

Are any Temporary DTCs or DTCs Indicated?

YES - If DTC P0137 and/or P0157* is indicated, check for poor connections or loose terminals at the secondary HO2S (Sensor 2) and the PCM, then go to step 1. If any other Temporary DTCs or DTCs are indicated, go to the indicated DTC's troubleshooting.

NO - Go to step 22.

22. Monitor the OBD STATUS for DTC P0137 and/or P0157* in the DTCs MENU with the HDS.

Does the screen indicate PASSED?

YES - Troubleshooting is complete.

NO - If the screen indicates FAILED, check for poor connections or loose terminals at the secondary HO2S (Sensor 2) and the PCM, then go to step 1. If the screen indicates EXECUTING, keep driving until a result comes on. If the screen indicates OUT OF CONDITION, go to step 19 and recheck.

23. Update the PCM if it does not have the latest software, or substitute a known-good PCM.
24. Start the engine. Hold the engine speed at 3,000 rpm without load (in Park or neutral) until the radiator fan comes on, then let it idle.
25. Test-drive under these conditions:
- ECT SENSOR 1 above 176 degrees F (80 degrees C)
- Transmission in D position
- Engine speed at 1,500 - 3,000 rpm
- Drive 1 minute or more

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

Are any Temporary DTCs or DTCs indicated?

YES - If DTC P0137 and/or P0157* is indicated, check for poor connections or loose terminals at the secondary HO2S (Sensor 2) and the PCM, then go step 1. If any other Temporary DTCs or DTCs are indicated, go to the indicated DTC's troubleshooting.

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