DTC Troubleshooting: P0135 (L4) - Honda Accord CR/CT 2012-2017

1.

Problem verification:

Problem verification

?1.	Turn the ignition switch to ON (II), or press the engine start/stop button to select 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 PGM-FI subrelay, and the PCM.?

2.

Fuse check:

Fuse check

?1.	Turn the ignition switch to LOCK (0), or press the engine start/stop button to select the OFF mode.

?2.

Check the following fuse.

Fuse	No. A7 (15 A)
Location	Under-hood fuse/relay box

Is the fuse OK?


	YES

Go to step 3.


	NO

Go to step 10.

3.

Relay check:

Relay check

?1.	Remove the PGM-FI subrelay (A) from the under-hood fuse/relay box.

?2.	Test the PGM-FI subrelay.

Is the PGM-FI subrelay OK?


	YES

Go to step 4.


	NO

Replace the PGM-FI subrelay, then do the repair verification.

4.

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

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	IG LOCK (0) or OFF mode
	PGM-FI subrelay: disconnected
	A/F sensor (Sensor 1) 4P connector: disconnected
Test circuit	LAF+, AFHT
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)

Is there 2.0?2.7 ? at room temperature?


	YES

Go to step 5.


	NO

Replace the A/F sensor (Sensor 1), then do the repair verification.

5.

A/F sensor internal circuit check:

A/F sensor internal circuit check

?1.

At the sensor side, check for continuity between the following test points and body ground individually.

Test condition	IG LOCK (0) or OFF mode
	PGM-FI subrelay: disconnected
	A/F sensor (Sensor 1) 4P connector: disconnected

Connector	Test circuit	Terminal
A/F sensor (Sensor 1) (A/F sensor (Sensor 1) side)	AFS-	No. 1
	AFHT	No. 3
	LAF+	No. 4

Is there continuity?


	YES

Replace the A/F sensor (Sensor 1), then do the repair verification.


	NO

Go to step 6.

6.

Shorted wire check (AFHT line):

Shorted wire check (AFHT line)

?1.	Jump the SCS line with the HDS.

?2.

Disconnect the following connector.

PCM connector C (51P)

?3.

Check for continuity between test points 1 and 2.

Test condition	IG LOCK (0) or OFF mode
	PGM-FI subrelay: disconnected
	A/F sensor (Sensor 1) 4P connector: disconnected
	PCM connector C (51P): disconnected
Test circuit	AFHT
Test point 1	PCM connector C (51P) No. 7 (GRN)
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), then do the repair verification.


	NO

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

7.

Open wire check (AFHT line):

Open wire check (AFHT line)

?1.

Check for continuity between test points 1 and 2.

Test condition	IG LOCK (0) or OFF mode
	PGM-FI subrelay: disconnected
	A/F sensor (Sensor 1) 4P connector: disconnected
	PCM connector C (51P): disconnected
Test circuit	AFHT
Test point 1	A/F sensor (Sensor 1) 4P connector No. 3 (GRN)
Test point 2	PCM connector C (51P) No. 7 (GRN)

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), then do the repair verification.

8.

Open wire check (LAF+/FI SUB RLY OUT line):

Open wire check (LAF+/FI SUB RLY OUT line)

?1.

Check for continuity between test points 1 and 2.

Test condition	IG LOCK (0) or OFF mode
	PGM-FI subrelay: disconnected
	A/F sensor (Sensor 1) 4P connector: disconnected
	PCM connector C (51P): disconnected
Test circuit	LAF+/FI SUB RLY OUT
Test point 1	PGM-FI subrelay 4P socket No. 2
Test point 2	A/F sensor (Sensor 1) 4P connector No. 4 (WHT/BLK)

Is there continuity?


	YES

The LAF+/FI SUB RLY OUT wire is OK. Go to step 9.


	NO

Repair an open in the LAF+/FI SUB RLY OUT wire between the A/F sensor (Sensor 1) and the PGM-FI subrelay, then do the repair verification.

9.

Open wire check (FI SUB RLY CL- line):

Open wire check (FI SUB RLY CL- line)

?1.

Disconnect the following connector.

PCM connector A (51P)

?2.

Check for continuity between test points 1 and 2.

Test condition	IG LOCK (0) or OFF mode
	PGM-FI subrelay: disconnected
	A/F sensor (Sensor 1) 4P connector: disconnected
	PCM connector A (51P): disconnected
Test circuit	FI SUB RLY CL-
Test point 1	PGM-FI subrelay 4P socket No. 4
Test point 2	PCM connector A (51P) No. 16 (PNK)

Is there continuity?


	YES

The FI SUB RLY CL- wire is OK. Update the PCM if it does not have the latest software, or substitute a known-good PCM, then do the repair verification.


	NO

Repair an open in the FI SUB RLY CL- wire between the PCM (A16) and the PGM-FI subrelay, then do the repair verification.

10.

Shorted wire check (LAF+/FI SUB RLY OUT line):

Shorted wire check (LAF+/FI SUB RLY OUT line)

?1.	Remove the PGM-FI subrelay (A) and the No. A23 (7.5 A) fuse from the under-hood fuse/relay box.

?2.	Jump the SCS line with the HDS.

?3.

Disconnect the following connectors.

PCM connector A (51P)

A/F sensor (Sensor 1) 4P connector

?4.

Check for continuity between test points 1 and 2.

Test condition	IG LOCK (0) or OFF mode
	PGM-FI subrelay: disconnected
	No. A23 (7.5 A) fuse: disconnected
	PCM connector A (51P): disconnected
	A/F sensor (Sensor 1) 4P connector: disconnected
Test circuit	LAF+
Test point 1	A/F sensor (Sensor 1) 4P connector No. 4 (WHT/BLK)
Test point 2	Body ground

Is there continuity?


	YES

Repair a short in the LAF+/FI SUB RLY OUT wire between the PGM-FI subrelay, the A/F sensor (Sensor 1), the No. A23 (7.5 A) fuse, and the PCM. Also replace the No. A7 (15 A) fuse in the under-hood fuse/relay box, then do the repair verification.


	NO

The LAF+/FI SUB RLY OUT wire is OK. Replace the under-hood fuse/relay box, then do the repair verification.

Repair verification (OBD STATUS check):

?1.	Reconnect all connectors.

?2.	Exit the SCS mode with the HDS.

?3.	Turn the ignition switch to ON (II), or press the engine start/stop button to select the ON mode.

?4.	Reset the PCM with the HDS.

?5.	Do the PCM idle learn procedure.

?6.

Monitor the OBD STATUS for DTC P0135 in the DTCs MENU with the HDS.

DTC Description	OBD STATUS
P0135 A/F Sensor (Sensor 1) Heater Circuit Malfunction

Does the HDS indicate PASSED, FAILED, or NOT COMPLETED?


	PASSED

Troubleshooting is complete. If the PCM was substituted, replace the original PCM. If any other Pending or Confirmed DTCs are indicated, go to the indicated DTC's troubleshooting.?


	FAILED

Go to step 1 and recheck. If the PCM was updated, substitute a known-good PCM, then check the OBD STATUS again.


	NOT COMPLETED

Keep the test condition until a result comes on.