( TL19E3AK72100091157FAAT00 )

DTC Troubleshooting: P1157 (48)

DTC P1157:
A/F Sensor (Sensor 1) AFS Circuit Malfunction
NOTE: Before you troubleshoot, record all freeze data and any on-board snapshot, and review the general troubleshooting information.

1. Turn the ignition switch to ON (II).

1. Clear the DTC with the HDS.

1. Start the engine, and wait 1 minute.

1. 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.■

1. Turn the ignition switch to LOCK (0).

1. Jump the SCS line with the HDS.

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

1. Disconnect ECM/PCM connector C (49P).

1. Check for continuity between A/F sensor (Sensor 1) 4P connector terminal No. 1 and ECM/PCM connector terminal C29.

Is there continuity?

YES | - | Go to Step 10 .
NO | - | Repair open in the wire between the ECM/PCM (C29) and the A/F sensor (Sensor 1), then go to Step 12 .

1. Check for continuity between A/F sensor (Sensor 1) 4P connector terminal No. 2 and ECM/PCM connector terminal C30.

Is there continuity?

YES | - | Go to Step 11 .
NO | - | Repair open in the wire between the ECM/PCM (C30) and the A/F sensor (Sensor 1), then go to Step 12 .

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

1. Reconnect all connectors.

1. Turn the ignition switch to ON (II).

1. Reset the ECM/PCM with the HDS.

1. Do the ECM/PCM idle learn procedure.

1. 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 18 .
NO | - | Go to Step 17 .

1. 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 16 , 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.

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

1. Start the engine, and let it idle.

1. 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 19 . If the ECM/PCM was substituted, go to Step 1 .
NO | - | Go to Step 21 .

1. 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 20 , 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 19 . If the ECM/PCM was substituted, go to Step 1 . If the screen indicates NOT COMPLETED, keep idling until a result comes on.