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 to 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 (A/T in P or N, M/T 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 PGM-FI subrelay, and the ECM/PCM.■
  1. Turn the ignition switch to LOCK (0).
  1. Check the No. 14 FI SUB (15 A) fuse in the under-hood fuse/relay box.
Is the fuse OK?
YES -
Go to Step 7 .
NO -
Go to Step 19 .
  1. Remove the PGM-FI subrelay (A) from the under-hood fuse/relay box.
  1. Test the PGM-FI subrelay.
Is the relay OK?
YES -
Go to Step 9 .
NO -
Replace the PGM-FI subrelay, then go to Step 24 .
  1. Disconnect the A/F sensor (Sensor 1) 4P connector.