DTC Troubleshooting
DTC P1157:A/F Sensor (Sensor 1) AFS Circuit High VoltageNOTE: Before you troubleshoot, record all freeze data and any on-board snapshot, and review the general troubleshooting information.
1. Turn the ignition switch ON (II).
2. Clear the DTC with the HDS.
3. Start the engine, and wait 1 minute.
4. Check for Temporary DTCs or DTCs with the HDS.
Is DTC P1157 indicated?
YES - Go to step 5.
NO - Intermittent failure, the system is OK at this time. Check for poor connections or loose terminals at the A/F sensor (Sensor 1) and the ECM/PCM.
5. Turn the ignition switch OFF.
6. Jump the SCS line with the HDS.
7. Disconnect the A/F sensor (Sensor 1) 4P connector.
8. Disconnect ECM/PCM connector A (31P).
9. Connect A/F sensor (Sensor 1) 4P connector terminals No. 1 and No. 2 with a jumper wire.
10. Check for continuity between ECM/PCM connector terminals A28 and A31.
Is there continuity?
YES - Go to step 14.
NO - Go to step 11.
11. Remove the jumper wire from the A/F sensor (Sensor 1) 4P connector.
12. Connect A/F sensor (Sensor 1) 4P connector terminal No. 2 to body ground with a jumper wire.
13. Check for continuity between ECM/PCM connector terminal A31 and body ground.
Is there continuity?
YES - Repair open in the wire between the ECM/PCM (A28) and the A/F sensor (Sensor 1), then Go to step 15.
NO - Repair open in the wire between the ECM/PCM (A31) and the A/F sensor (Sensor 1), then Go to step 15.
14. Replace the A/F sensor (Sensor 1).
15. Reconnect all connectors.
16. Turn the ignition switch ON (II).
17. Reset the ECM/PCM with the HDS.
18. Do the ECM/PCM idle learn procedure.
19. Check for Temporary DTCs or DTCs with the HDS.
Is DTC P1157 indicated?
YES - Check for poor connections or loose terminals at the A/F sensor (Sensor 1) and the ECM/PCM, then Go to step 1. If the connector and terminal fits are OK, Go to step 21.
NO - Go to step 20.
20. Monitor the OBD STATUS for DTC P1157 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 19, Go to the indicated DTC's troubleshooting.
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 step 1. If the screen indicates NOT COMPLETED, keep idling until a result comes on.
21. Update the ECM/PCM if it does not have the latest software, or substitute a known good ECM/PCM.
22. Start the engine, and let it idle.
23. Check for Temporary DTCs or DTCs with the HDS.
Is DTC P1157 indicated?
YES - If the ECM/PCM was updated, substitute a known good ECM/PCM, then Go to step 22. If the ECM/PCM was substituted, Go to step 1.
NO - Go to step 24.
24. Monitor the OBD STATUS for DTC P1157 in the DTCs MENU with the HDS.
Does the screen indicate PASSED?
YES - If the ECM/PCM was updated, troubleshooting is complete. If the ECM/PCM was substituted, replace the original ECM/PCM. If any other Temporary DTCs or DTCs were indicated in step 23, Go to the indicated DTC's troubleshooting.
NO - If the screen indicates FAILED, Go to step 1. If the ECM/PCM was updated, substitute a known good ECM/PCM, then Go to step 22. If the ECM/PCM was substituted, Go to step 1. If the screen indicates NOT COMPLETED, keep idling until a result comes on.