DTC Troubleshooting
DTC P0138: Rear Secondary HO2S (Bank 1, Sensor 2) Circuit High VoltageDTC P0158: Front Secondary HO2S (Bank 2, Sensor 2) Circuit High 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 1.25 V or more?
YES - Go to step 5.
NO - Intermittent failure, the 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. Connect secondary HO2S (Sensor 2) 4P connector terminals No. 1 and No. 2 with a jumper wire.
8. Turn the ignition switch ON (II).
9. Check the HO2S S2 in the DATA LIST with the HDS.
Does the voltage stay at 1.25 V or more?
YES - Go to step 10.
NO - Go to step 19.
10. Turn the ignition switch OFF.
11. Remove the jumper wire from the secondary HO2S (Sensor 2) 4P connector.
12. Connect secondary HO2S (Sensor 2) 4P connector terminal No. 1 to body ground with a jumper wire.
13. Turn the ignition switch ON (II).
14. Check the HO2S S2 in the DATA LIST with the HDS.
Does the voltage stay at 1.25 V or more?
YES - Go to step 15.
NO - Repair open in the wire between the PCM (C12) and the secondary HO2S (Sensor 2), then Go to step 21.
15. Turn the ignition switch OFF.
16. Jump the SCS line with the HDS.
17. Disconnect PCM connector B (24P).
18. Check for continuity between PCM connector terminal 89 (B18)* and body ground.
Is there continuity?
YES - Go to step 29.
NO - Repair open in the wire between the PCM (B9 (B18)*) and the secondary HO2S (Sensor 2), then Go to step 21.
19. Turn the ignition switch OFF.
20. Replace the secondary HO2S (Sensor 2).
21. Reconnect all connectors.
22. Turn the ignition switch ON (II).
23. Reset the PCM with the HDS.
24. Do the PCM idle learn procedure.
25. 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.
26. Test-drive under these conditions:
- Engine coolant temperature (ECT SENSOR 1) above 176 °F(80 °C)
- Transmission in D position
- Engine speed at 1,500 - 3,000 rpm
- Drive 1 minute or more.
27. Check for Temporary DTCs or DTCs with the HDS.
Is DTC P0138 and/or P0158* indicated?
YES - Check for poor connections or loose terminals at the secondary HO2S (Sensor 2) and the PCM, then Go to step 1.
NO - Go to step 28.
28. Monitor the 08D STATUS for DTC P0138 and/or P0158* in the DTCs MENU with the HDS.
Does the screen indicate PASSED?
YES - Troubleshooting is complete. If any other Temporary DTCs or DTCs were indicated in step 27, Go to the indicated DTC's troubleshooting.
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 25.
29. Update the PCM if it does not have the latest software, or substitute a known good PCM.
30. 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.
31. Test-drive under these conditions:
- Engine coolant temperature (ECT SENSOR 1) above 176 °F(80 °C)
- Transmission in D position
- Engine speed at 1,500 - 3,000 rpm
- Drive 1 minute or more
32. Check for Temporary DTCs or DTCs with the HDS.
Is DTC P0138 and/or P0158* indicated?
YES - Check for poor connections or loose terminals at the secondary HO2S (Sensor 2) and the PCM. If the PCM was updated, substitute a known good PCM, then Go to step 30. If the PCM was substituted, Go to step 1.
NO - Go to step 33.
33. Monitor the OBD STATUS for DTC P0138 and/or P0158* in the DTCs MENU with the HDS.
Does the screen indicate PASSED?
YES - If the PCM was updated, troubleshooting is complete. If the PCM was substituted, replace the original PCM. If any other Temporary DTCs or DTCs were indicated in step 32, Go to the indicated DTC's troubleshooting.
NO - If the screen indicates FAILED, check for poor connections or loose terminals at the secondary HO2S (Sensor 2) and the PCM. If the PCM was updated, substitute a known good PCM, then Go to step 30. If the PCM was substituted, Go to step 1. If the screen indicates NOT COMPLETED, Go to step 30.