( TF09EACK72100091157FAAT00 )
DTC Troubleshooting: P1157 (48)
DTC P1157:
 A/F Sensor (Sensor 1) Circuit High Voltage
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. Reconnect all connectors.
  1. Turn the ignition switch to ON (II).
  1. Reset the ECM/PCM with the HDS.
  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, go to Step 15 .
  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, let the until a result comes on.