DTC Troubleshooting: P1157 (48)
DTC P1157:
 A/F Sensor (Sensor 1) AFS Line 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 ON (II).
  1. Clear the DTC with the HDS.
  1. Start the engine, and wait for 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.■
  1. Turn the ignition switch OFF.
  1. Jump the SCS line with the HDS.
  1. Disconnect the A/F sensor (Sensor 1) 4P connector.
  1. Disconnect ECM connector C (44P).
  1. Connect A/F sensor (Sensor 1) 4P connector terminals No. 1 and No. 2 with a jumper wire.
  1. Check for continuity between ECM connector terminal C29 and C30.
Is there continuity?
YES -
Go to Step 14 .
NO -
Go to Step 11 .
  1. Remove the jumper wire from the A/F sensor (Sensor 1) 4P connector.
  1. Connect A/F sensor (Sensor 1) 4P connector terminal No. 2 to body ground with a jumper wire.
  1. Check for continuity between ECM connector terminal C29 and body ground.
Is there continuity?
YES -
Repair open in the wire between the ECM (C30) and the A/F sensor (Sensor 1), then go to Step 15 .
NO -
Repair open in the wire between the ECM (C30) and the A/F sensor (Sensor 1), then go to Step 15 .
  1. Reconnect all connectors and the battery.
  1. Turn the ignition switch ON (II).
  1. Reset the ECM 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, then go to Step 1 . If the connector and terminal fits are OK, go to Step 21 .
NO -
Go to Step 20 .
  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 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, then go to Step 1 . If the screen indicates NOT COMPLETED, go to Step 18 .
  1. Start the engine.
  1. Check for Temporary DTCs or DTCs with the HDS.
Is DTC P1157 indicated?
YES -
If the ECM was updated, substitute a known-good ECM, then go to Step 22 . If the ECM was substituted, go to Step 1 .
NO -
Go to Step 24 .
  1. Monitor the OBD STATUS for DTC P1157 in the DTCs MENU with the HDS.
Does the screen indicate PASSED?
YES -
If the ECM was updated, troubleshooting is complete. If the ECM was substituted, replace the original ECM. 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 was updated, substitute a known-good ECM, then go to Step 22 . If the ECM was substituted, go to Step 1 . If the screen indicates NOT COMPLETED, keep idling until a result comes on.