ο‘
4. Check for Pending or Confirmed DTCs with the HDS.
Confirmed
DTC
Pending
DTC
Freeze
Frame
DTC Description
P0134 A/F SENSOR (SENSOR 1) HEATER SYSTEM
MALFUNCTION
Is DTC P0134 indicated?
YES : The failure is duplicated. REPLACE THE A/F SENSOR (SENSOR 1) , then do the repair
verification .
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.
REPAIR VERIFICATION (OBD STATUS CHECK)
ο‘
ο‘
1. Turn the ignition switch to ON (II).
2. Reset the PCM with the HDS See HOW TO TROUBLESHOOT THE A/T SYSTEM or HOW
TO TROUBLESHOOT THE FUEL AND EMISSIONS SYSTEMS .
ο‘
ο‘
3. DO THE PCM IDLE LEARN PROCEDURE .
4. Monitor the OBD STATUS for DTC P0134 in the DTCs MENU with the HDS.
DTC Description
OBD STATUS
P0134 A/F SENSOR (SENSOR 1) HEATER SYSTEM MALFUNCTION
Does the HDS indicate PASSED, FAILED, or NOT COMPLETED?
PASSED : Troubleshooting is complete. If any other Pending or Confirmed DTCs are indicated, go to the
indicated DTC's troubleshooting.
FAILED : Go to step 1 and recheck.
NOT COMPLETED : Keep the test condition until a result comes on.
DTC P0135: A/F SENSOR (SENSOR 1) HEATER CIRCUIT MALFUNCTION
Fig. 54: DTC Troubleshooting Flow Chart (P0135)
Courtesy of AMERICAN HONDA MOTOR CO., INC.
NOTE:
Before you troubleshoot, record all freeze data and any on-board snapshot, and
review the general troubleshooting information See HOW TO TROUBLESHOOT
THE FUEL AND EMISSIONS SYSTEMS or HOW TO TROUBLESHOOT THE A/T
SYSTEM .
Confirmed
DTC
Pending
DTC
Freeze
Frame
DTC Description
P0135 A/F SENSOR (SENSOR 1) HEATER CIRCUIT
MALFUNCTION
1. Problem verification:
ο‘
1. Turn the ignition switch to ON (II).
ο‘
2. Clear the DTC with the HDS See HOW TO TROUBLESHOOT THE FUEL AND
EMISSIONS SYSTEMS or HOW TO TROUBLESHOOT THE A/T SYSTEM .
ο‘
ο‘
3. Start the engine. Hold the engine speed at 3, 000 rpm without load (in P or N) until the radiator
fan comes on, then let it idle.
4. Check for Pending or Confirmed DTCs with the HDS.
Confirmed
DTC
Pending
DTC
Freeze
Frame
DTC Description
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:
ο‘
1. Turn the ignition switch to LOCK (0).
2. Check the following fuse.
ο‘
Fuse No. A18 (15 A)
Location Under-hood fuse/relay box
Is the fuse OK?
YES : Go to step 3.
NO : Go to step 9.
3. Relay check:
ο‘
1. Remove the PGM-FI subrelay (A) from the under-hood fuse/relay box.
Fig. 55: Identifying PGM-FI Relay Box Subrelay
Courtesy of AMERICAN HONDA MOTOR CO., INC.
ο‘
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:
ο‘
1. Disconnect the following connector.
A/F sensor (Sensor 1) 4P connector
ο‘
2. At the sensor side, measure the resistance between test points 1 and 2.
Test condition IG LOCK (0)
PGM-FI subrelay: disconnected
A/F sensor (Sensor 1) 4P connector: disconnected
Test circuit AFHT, LAF+,
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)
Fig. 56: Measuring Resistance Between A/F Sensor (Sensor 1) 4P Connector No. 3 And No. 4
Courtesy of AMERICAN HONDA MOTOR CO., INC.
Is there 2.2-2.7 ohms 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 (Sensor 1) internal circuit check:
ο‘
1. At the sensor side, check for continuity between test points 1 and 2.
Test condition IG LOCK (0)
PGM-FI subrelay: disconnected
A/F sensor (Sensor 1) 4P connector: disconnected
Test circuit AFS-, LAF+
Test point 1 A/F sensor (Sensor 1) 4P connector No. 1 (A/F sensor (Sensor 1) side)
Test point 2 A/F sensor (Sensor 1) 4P connector No. 4 (A/F sensor (Sensor 1) side)
Test circuit AFS-, AFHT
Test point 1 A/F sensor (Sensor 1) 4P connector No. 1 (A/F sensor (Sensor 1) side)
Test point 2 A/F sensor (Sensor 1) 4P connector No. 3 (A/F sensor (Sensor 1) side)
Fig. 57: Checking Continuity Between A/F Sensor (Sensor 1) 4P Connector No. 1 And No. 3
Courtesy of AMERICAN HONDA MOTOR CO., INC.
Is there continuity?
YES : REPLACE THE A/F SENSOR (SENSOR 1) , then do the repair verification .
NO : Go to step 6.
6. Open wire check (AFHT line):
ο‘
1. Jump the SCS line with the HDS.
2. Disconnect the following connector.
ο‘
PCM connector C (49P)
ο‘
3. Check for continuity between test points 1 and 2.
Test condition IG LOCK (0)
PGM-FI subrelay: disconnected
A/F sensor (Sensor 1) 4P connector: disconnected
PCM connector C (49P): disconnected
Test circuit AFHT
Test point 1 PCM connector C (49P) No. 9 (GRN)
Test point 2 A/F sensor (Sensor 1) 4P connector No. 3 (GRN)
Fig. 58: Checking Continuity Between PCM Connector C (49P) No. 9 (GRN) And A/F Sensor
(Sensor 1) 4P Connector No. 3 (GRN)
Courtesy of AMERICAN HONDA MOTOR CO., INC.
Is there continuity?
YES : The AFHT wire is OK. Go to step 7.
NO : Repair an open in the AFHT wire between the PCM (C9) and the A/F sensor (Sensor 1), then do the
repair verification .
7. Open wire check (LAF+/FI SUB RLY OUT line):
ο‘
1. Check for continuity between test points 1 and 2.
Test condition IG LOCK (0)
PGM-FI subrelay: disconnected
A/F sensor (Sensor 1) 4P connector: disconnected
PCM connector C (49P): disconnected
Test circuit LAF+/FI SUB RLY OUT
Test point 1 PGM-FI subrelay 4P socket No. 2 (Under-hood fuse/relay box)
Test point 2 A/F sensor (Sensor 1) 4P connector No. 4 (LT BLU)
Fig. 59: Checking Continuity Between PGM-FI Subrelay 4P Socket No. 2 (Under-Hood
Fuse/Relay Box) And A/F Sensor (Sensor 1) 4P Connector No. 4 (Lt Blu)
Courtesy of AMERICAN HONDA MOTOR CO., INC.
Is there continuity?
YES : The LAF+/FI SUB RLY OUT wire is OK. Go to step 8.
NO : Repair an open in the AFHT+/FI SUB RLY OUT wire between the A/F sensor (Sensor 1) and the
PGM-FI subrelay, then do the repair verification .
8. Open wire check (FI SUB RLY CL- line):
ο‘
1. Disconnect the following connector.
PCM connector A (49P)
ο‘
2. Check for continuity between test points 1 and 2.
Test condition IG LOCK (0)
PGM-FI subrelay: disconnected
A/F sensor (Sensor 1) 4P connector: disconnected
PCM connector C (49P): disconnected
PCM connector A (49P): disconnected
Test circuit FI SUB RLY CL-
Test point 1 PCM connector A (49P) No. 20 (WHT)
Test point 2 PGM-FI subrelay 4P socket No. 4 (Under-hood fuse/relay box)
Fig. 60: Checking Continuity Between PCM Connector A (49P) No. 20 (WHT) And PGM-FI
Subrelay 4P Socket No. 4 (Under-Hood Fuse/Relay Box)
Courtesy of AMERICAN HONDA MOTOR CO., INC.
Is there continuity?
YES : The FI SUB RLY CL- wire is OK. Update the PCM See PCM REMOVAL AND
INSTALLATION or PCM UPDATE if it does not have the latest software, or substitute a known-
good PCM See PCM REMOVAL AND INSTALLATION or PCM UPDATE , then do the repair
verification .
NO : Repair an open in the FI SUB RLY CL- wire between the PCM (A20) and the PGM-FI subrelay,
then do the repair verification .
9. Shorted wire check (LAF+/FI SUB RLY OUT line):
ο‘
1. Remove the PGM-FI subrelay (A) and the A/C condenser fan relay (B) from the under-hood
fuse/relay box.
Fig. 61: Identifying PGM-FI Subrelay And A/C Condenser Fan Relay
Courtesy of AMERICAN HONDA MOTOR CO., INC.
ο‘
ο‘
2. Jump the SCS line with the HDS.
3. Disconnect the following connector.
PCM connector A (49P)
A/F sensor (Sensor 1) 4P connector
EVAP canister vent shut valve 2P connector
4. Check for continuity between test points 1 and 2.
Test condition IG LOCK (0)
ο‘
PGM-FI subrelay: disconnected
A/C condenser fan relay: disconnected
PCM connector A (49P): disconnected
A/F sensor (Sensor 1) 4P connector: disconnected
EVAP canister vent shut valve 2P connector: disconnected
Test circuit LAF+
Test point 1 A/F sensor (Sensor 1) 4P connector No. 4 (LT BLU)
Test point 2 Body ground
Fig. 62: Checking Continuity Between A/F Sensor (Sensor 1) 4P Connector No. 4 (LT BLU)
And Body Ground
Courtesy of AMERICAN HONDA MOTOR CO., INC.
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 A/C condenser fan relay, EVAP canister vent shut valve, and the EVAP canister vent shut
valve. Also replace the No. A18 (15 A) fuse, 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)
ο‘
ο‘
ο‘
ο‘
1. Turn the ignition switch to LOCK (0).
2. Reconnect all connectors.
3. Turn the ignition switch to ON (II).
4. Reset the PCM with the HDS See HOW TO TROUBLESHOOT THE FUEL AND EMISSIONS
SYSTEMS or HOW TO TROUBLESHOOT THE A/T SYSTEM .
ο‘
ο‘
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 See PCM
REMOVAL AND INSTALLATION or PCM UPDATE . 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 See PCM
REMOVAL AND INSTALLATION or PCM UPDATE , then check the OBD STATUS again.
NOT COMPLETED : Keep the test condition until a result comes on.
DTC P0137: SECONDARY HO2S (SENSOR 2) CIRCUIT LOW VOLTAGE
Fig. 63: DTC Troubleshooting Flow Chart (P0137)
Courtesy of AMERICAN HONDA MOTOR CO., INC.
2024 Honda CR-V Owner's Manual
2023 Honda CR-V Owner's Manual
2021 Honda CR-V Owner's Manual
2018 Honda CR-V Owner's Manual
2015 Honda CR-V Owner's Manual
