DTC Troubleshooting: P0135 (41)
DTC P0135:
 A/F Sensor (Sensor 1) Heater 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 ON (II).
  1. Clear the DTC with the HDS.
  1. Start the engine. Hold the engine speed at 3,000 rpm (min −1 ) without load (in neutral) until the radiator fan comes on, then let it idle.
  1. Check for Temporary DTCs or DTCs with the HDS.
Is DTC P0135 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), the under-hood fuse/relay box, and the ECM.■
  1. Turn the ignition switch OFF.
  1. Check the No. 13 LAF (A/F SENSOR) (15 A) fuse in the under-hood fuse/relay box.
Is the fuse OK?
YES -
Go to Step 7 .
NO -
Go to Step 18 .
Is the PGM-FI subrelay OK?
YES -
Go to Step 8 .
NO -
Replace the under-hood fuse/relay box, then go to Step 22 .
  1. Disconnect the A/F sensor (Sensor 1) 4P connector.
  1. At the sensor side, measure resistance between A/F sensor (Sensor 1) 4P connector terminals No. 3 and No. 4.
Is there 1.9−2.5 Ω at room temperature?
YES -
Go to Step 10 .
NO -
Go to Step 21 .
  1. At the sensor side, check for continuity between A/F sensor (Sensor 1) 4P connector terminals No. 1 and No. 3, and between terminals No. 1 and No. 4 individually.
Is there continuity?
YES -
Go to Step 21 .
NO -
Go to Step 11 .
  1. Jump the SCS line with the HDS.
  1. Disconnect ECM connector C (44P).
  1. Check for continuity between A/F sensor (Sensor 1) 4P connector terminal No. 3 and ECM connector terminal C9.
Is there continuity?
YES -
Go to Step 14 .
NO -
Repair open in the wire between the ECM (C9) and the A/F sensor (Sensor 1), then go to Step 22 .
  1. Check for continuity between A/F sensor (Sensor 1) 4P connector terminal No. 4 and under-hood fuse/relay box connector D (20P) terminal No. 9.
Is there continuity?
YES -
Go to Step 16 .
NO -
Repair open in the wire between the A/F sensor (Sensor 1) and the under-hood fuse/relay box, then go to Step 22 .
  1. Disconnect ECM connector A (44P).
  1. Check for continuity between under-hood fuse/relay box connector D (20P) terminal No. 20 and ECM connector terminal A21.
Is there continuity?
YES -
Go to Step 28 .
NO -
Repair open in the wire between the ECM (A21) and the under-hood fuse/relay box, then go to Step 22 .
  1. Disconnect the A/F sensor (Sensor 1) 4P connector.
  1. Check for continuity between A/F sensor (Sensor 1) 4P connector terminal No. 4 and body ground.
Is there continuity?
YES -
Repair short in the wire between the under-hood fuse/relay box and the A/F sensor (Sensor 1). Also replace the No. 13 LAF (A/F SENSOR) (15 A) fuse, then go to Step 22 .
NO -
Replace the under-hood fuse/relay box, then go to Step 22 .
  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 P0135 indicated?
YES -
Check for poor connections or loose terminals at the A/F sensor (Sensor 1), the under-hood fuse/relay box, and the ECM, then go to Step 1 .
NO -
Go to Step 27 .
  1. Monitor the OBD STATUS for DTC P0135 in the DTCs MENU with the HDS.
Does the screen indicate PASSED?
YES -
Troubleshooting is complete. If any other Temporary DTCs or DTCs ware indicated in Step 26 , 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), the under-hood fuse/relay box, and the ECM, then go to Step 1 . If the screen indicates NOT COMPLETED, go to Step 25 .
  1. Reconnect all connectors.
  1. Start the engine.
  1. Check for Temporary DTCs or DTCs with the HDS.
Is DTC P0135 indicated?
YES -
Check for poor connections or loose terminals at the A/F sensor (Sensor 1), the under-hood fuse/relay box, and the ECM, If the ECM was updated, substitute a known-good ECM, then go to Step 30 . If the ECM was substituted, go to Step 1 .
NO -
Go to Step 32 .
  1. Monitor the OBD STATUS for DTC P0135 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 ware indicated in Step 31 , 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), the under-hood fuse/relay box, and the ECM. If the ECM was updated, substitute a known-good ECM, then go to Step 30 . If the ECM was substituted, go to Step 1 . If the screen indicates NOT COMPLETED, keep idling until a result comes on.