DTC P0036, P0056: Rear Secondary HO2S (Bank 1, Sensor 2) Heater Circuit Malfunction; Front Secondary HO2S (Bank 2, Sensor 2) Heater Circuit Malfunction

NOTE:

Before you troubleshoot, record all freeze data and any on-board snapshot, and review the general troubleshooting information (see GENERAL TROUBLESHOOTING INFORMATION ).
Information marked with an asterisk (*) applies to the front bank (Bank 2).

Turn the ignition switch ON (II).
Clear the DTC with the HDS.
Start the engine.
Check for Temporary DTCs or DTCs with the HDS.
Is DTC P0036 and/or P0056* indicated?
1. YES - Go to step 5.
2. NO - Intermittent failure, system is OK at this time. Check for poor connections or loose terminals at the secondary HO2S (Sensor 2) and the PCM.
Turn the ignition switch OFF.
Disconnect the secondary HO2S (Sensor 2) 4P connector.
At the secondary HO2S (Sensor 2) side, measure resistance between secondary HO2S (Sensor 2) 4P connector terminals No. 3 and No. 4.

Fig 1: Measuring Resistance Between Secondary HO2S (Sensor 2) 4P Connector Terminals 3 And 4
Courtesy of AMERICAN HONDA MOTOR CO., INC.

Is there 5.4 - 6.6 Ω at room temperature?
1. YES - Go to step 8.
2. NO - Go to step 14.
Check for continuity between body ground and secondary HO2S (Sensor 2) 4P connector terminals No. 3 and No. 4 individually.

Fig 2: Checking Continuity Between Body Ground And Secondary HO2S (Sensor 2) 4P Connector Terminals 3 And 4
Courtesy of AMERICAN HONDA MOTOR CO., INC.

Is there continuity?
1. YES - Go to step 14.
2. NO - Go to step 9.
Jump the SCS line with the HDS.
Disconnect PCM connector A (73P).
Check for continuity between PCM connector terminal A59 (A60)* and body ground.

Fig 3: Checking Continuity Between PCM Connector Terminal A59 (A60)* And Body Ground
Courtesy of AMERICAN HONDA MOTOR CO., INC.

Is there continuity?
1. YES - Repair short in the wire between the PCM (A59 (A60)*) and the secondary HO2S (Sensor 2), then go to step 15.
2. NO - Go to step 12.
Connect secondary HO2S (Sensor 2) 4P connector terminal No. 3 to body ground with a jumper wire.

Fig 4: Connecting Secondary HO2S (Sensor 2) 4P Connector Terminal 3 To Body Ground With Jumper Wire
Courtesy of AMERICAN HONDA MOTOR CO., INC.
Check for continuity between PCM connector terminal A59 (A60)* and body ground.

Fig 5: Checking Continuity Between PCM Connector Terminal A59 (A60)* And Body Ground
Courtesy of AMERICAN HONDA MOTOR CO., INC.

Is there continuity?
1. YES - Go to step 20.
2. NO - Repair open in the wire between the PCM (A59 (A60)*) and the secondary HO2S (Sensor 2), then go to step 15.
Replace the secondary HO2S (Sensor 2) (see SECONDARY HO2S REPLACEMENT ).
Reconnect all connectors.
Turn the ignition switch ON (II).
Reset the PCM with the HDS.
Do the PCM idle learn procedure (see PCM IDLE LEARN PROCEDURE ).
Check for Temporary DTCs or DTCs with the HDS.
Are any Temporary DTCs or DTCs indicated?
1. YES - If DTC P0036 and/or P0056* is indicated, check for poor connections or loose terminals at the secondary HO2S (Sensor 2) and the PCM, then go to step 1. If any other Temporary DTCs or DTCs are indicated, go to the indicated DTC's troubleshooting.
2. NO - Go to step 20.
Update the PCM if it does not have the latest software, or substitute a known-good PCM (see PCM UPDATING AND SUBSTITUTION FOR TESTING ).
Check for Temporary DTCs or DTCs with the HDS.
Are any Temporary DTCs or DTCs indicated?
1. YES - If DTC P0036 and/or P0056* is indicated, check for poor connections or loose terminals at the secondary HO2S (Sensor 2) and the PCM, then go to step 1. If any other Temporary DTCs or DTCs are indicated, go to the indicated DTC's troubleshooting.
2. NO - If the PCM was updated, troubleshooting is complete. If the PCM was substituted, replace the original PCM (see PCM REPLACEMENT ).