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 for 20 seconds.
4. Check for Temporary DTCs or DTCs with the HDS.
Is DTC P1157 indicated?
YES - Go to step 5.
NO - Intermittent failure, 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. 1 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 - If Temporary DTC or DTC P1157 is not indicated, or if any other Temporary DTCs or DTCs are indicated, 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 - If there was no Temporary DTCs or DTCs indicated on step 19, troubleshooting is complete. If any other Temporary DTCs or DTCs was indicated on 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, go to step 18 and recheck.
21. Update the ECM/PCM if it does not have the latest software, or substitute a known-good ECM/PCM.
22. Start the engine.
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 - If Temporary DTC or DTC P1157 is not indicated, or if any other Temporary DTCs or DTCs are indicated, 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 was indicated on 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, let the engine idle until a result comes on.