DTC P0135: A / F Sensor (Sensor 1) Heater Circuit Malfunction

NOTE:  Before you troubleshoot, review the general troubleshooting information - Refer to: HOW TO TROUBLESHOOT THE FUEL AND EMISSIONS SYSTEMS or How to Troubleshoot the CVT System (CVT) .

DTC (PGM-FI)

1. Problem verification:

   - 1. Turn the vehicle to the ON mode.

   - 2. Clear the DTC with the HDS.

   - 3. Start the engine.

   - 4. Check for Pending or Confirmed DTCs with the HDS.

   DTC Description	Confirmed DTC	Pending DTC	Freeze Frame
   P0135 A/F Sensor (Sensor 1) Heater Circuit Malfunction

   Is DTC P0135 indicated?

   YES 

   The failure is duplicated. Go to step 2.

   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 ETCS control relay, and the PCM. If the freeze data/on-board snapshot of this DTC is recorded, try to reproduce the failure under the same conditions with the freeze data/on-board snapshot.

2. DTC check:

   - 1. Check for Pending or Confirmed DTCs with the HDS.

   DTC Description	Confirmed DTC	Pending DTC	Freeze Frame
   P1658 ETCS Control Relay ON Malfunction
   P1659 ETCS Control Relay OFF Malfunction

   Is DTC P1658 and/or P1659 indicated?

   YES 

   Go to the indicated DTC's troubleshooting.

   NO 

   Go to step 3.

3. Fuse check:

   - 1. Turn the vehicle to the OFF (LOCK) mode.

   - 2. Check the following fuse.

   Fuse	No. B30 (10 A)
   Location	Under-hood fuse/relay box

   Is the fuse OK?

   YES 

   Go to step 4.

   NO 

   Go to step 9.  9

4. A/F sensor (Sensor 1) internal heater resistance check:

   - 1. Disconnect the following connector.

   A/F sensor (Sensor 1) 4P connector

   - 2. At the sensor side, measure the resistance between test points 1 and 2.

   Test condition	Vehicle OFF (LOCK) mode
   	A/F sensor (Sensor 1) 4P connector: disconnected
   Test point 1	A/F sensor (Sensor 1) 4P connector No. 3 (A/F sensor (Sensor 1) side)
   Test point 2	A/F sensor (Sensor 1) 4P connector No. 4 (A/F sensor (Sensor 1) side)

   Courtesy of HONDA, U.S.A., INC.

   Is there 2.0-2.7 - at room temperature-

   YES 

   Go to step 5.

   NO 

   Replace the A/F sensor (Sensor 1) .

5. A/F sensor (Sensor 1) internal circuit check:

   - 1. Check for continuity between the following test points and the A/F sensor (Sensor 1) 4P connector No. 1 individually.

   Test condition	Vehicle OFF (LOCK) mode
   	A/F sensor (Sensor 1) 4P connector: disconnected

   Connector	Terminal
   A/F sensor (Sensor 1) (A/F sensor (Sensor 1) side)	No. 3
   	No. 4

   Courtesy of HONDA, U.S.A., INC.

   Is there continuity?

   YES 

   Replace the A/F sensor (Sensor 1) .

   NO 

   Go to step 6.

6. Shorted wire check (AFHT line):

   - 1. Jump the SCS line with the HDS.

   SCS Short

   - 2. Disconnect the following connector.

   PCM connector C (51P)

   - 3. Check for continuity between test points 1 and 2.

   Test condition	Vehicle OFF (LOCK) mode
   	A/F sensor (Sensor 1) 4P connector: disconnected
   	PCM connector C (51P): disconnected
   Test point 1	PCM connector C (51P) No. 7
   Test point 2	Body ground

   Is there continuity?

   YES 

   Repair a short in the AFHT wire between the PCM (C7) and the A/F sensor (Sensor 1).

   NO 

   The AFHT wire is not shorted. Go to step 7.

7. Open wire check (AFHT line):

   - 1. Check for continuity between test points 1 and 2.

   Test condition	Vehicle OFF (LOCK) mode
   	A/F sensor (Sensor 1) 4P connector: disconnected
   	PCM connector C (51P): disconnected
   Test point 1	A/F sensor (Sensor 1) 4P connector No. 4
   Test point 2	PCM connector C (51P) No. 7

   Courtesy of HONDA, U.S.A., INC.

   Is there continuity?

   YES 

   The AFHT wire is OK. Go to step 8.

   NO 

   Repair an open in the AFHT wire between the PCM (C7) and the A/F sensor (Sensor 1).

8. Open wire check (IGPS (LAF) line):

   - 1. Turn the vehicle to the ON mode.

   - 2. Measure the voltage between test points 1 and 2.

   Test condition	Vehicle ON mode
   	A/F sensor (Sensor 1) 4P connector: disconnected
   	PCM connector C (51P): disconnected
   Test point 1	A/F sensor (Sensor 1) 4P connector No. 3
   Test point 2	Body ground

   Courtesy of HONDA, U.S.A., INC.

   Is there battery voltage?

   YES 

   The IGPS (LAF) wire is OK. Update the PCM if it does not have the latest software, or substitute a known-good PCM , then recheck. If DTC P0135 goes away and the PCM was updated, troubleshooting is complete. If DTC P0135 goes away and the PCM was substituted, replace the original PCM .

   NO 

   Repair an open in the IGPS (LAF) wire between the A/F sensor (Sensor 1) and the No. B30 (10 A) fuse in the under-hood fuse/relay box.

9. Shorted wire check (IGPS (LAF) line):

   - 1. Remove the No. B30 (10 A) fuse from the under-hood fuse/relay box.

   - 2. Check for continuity between test points 1 and 2.

   Test condition	Vehicle OFF (LOCK) mode
   	No. B30 (10 A) fuse: removed
   	A/F sensor (Sensor 1) 4P connectors: disconnected
   Test point 1	A/F sensor (Sensor 1) 4P connector No. 3
   Test point 2	Body ground

   Courtesy of HONDA, U.S.A., INC.

   Is there continuity?

   YES 

   Repair a short in the IGPS (LAF) wire between the A/F sensor (Sensor 1) and the No. B30 (10 A) fuse in the under-hood fuse/relay box. Also replace the No. B30 (10 A) fuse.

   NO 

   The IGPS (LAF) wire is OK. Replace the No. B30 (10 A) fuse in the under-hood fuse/relay box and recheck. If the fuse is blown again, replace the under-hood fuse/relay box .