DTC P0141, P0161 (6-Speed A/T, '16-'18 9-Speed A/T)
DTC P0141 : Rear Secondary HO2S (Bank 1, Sensor 2) Heater Circuit Malfunction
DTC P0161 : Front Secondary HO2S (Bank 2, Sensor 2) Heater Circuit Malfunction
NOTE:
- Before you troubleshoot, review the general troubleshooting information - Refer to: How to Troubleshoot the Fuel and Emissions Systems
- Information marked with an asterisk (*) applies to the front bank (Bank 2).
| DTC Description | Confirmed DTC | Pending DTC | Freeze Frame |
|---|---|---|---|
| P0141 Rear Secondary HO2S (Bank 1, Sensor 2) Heater Circuit Malfunction | |||
| P0161 Front Secondary HO2S (Bank 2, Sensor 2) Heater Circuit Malfunction |
DTC (PGM-FI)
- Problem verification
-1. Turn the vehicle to the ON mode.
- 2. Clear the DTC with the HDS.
DTC (PGM-FI)
- 3. Start the engine, and let it idle.
- 4. Check for Pending or Confirmed DTCs with the HDS.
DTC Description Confirmed DTC Pending DTC Freeze Frame P0141 Rear Secondary HO2S (Bank 1, Sensor 2) Heater Circuit Malfunction P0161 Front Secondary HO2S (Bank 2, Sensor 2) Heater Circuit Malfunction Is DTC P0141 and/or P0161 * 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 secondary HO2S (Sensor 2) 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 - Refer to: How to Troubleshoot the Fuel and Emissions Systems
- Determine possible failure area (IG (LAF O2)/FI SUB line, others)
-1. Turn the vehicle to the OFF (LOCK) mode.
- 2. Check the following fuse.
Fuse No. A22 (15 A) Location Under-hood fuse/relay box Is the fuse OK?
YES
The IG (LAF O2)/FI SUB wire is not shorted. Go to step 3.
NO
Go to step 10.
- Relay circuit board check
-1. Remove and test the relay circuit board.
Is the relay circuit board OK?
YES
The relay circuit board is OK. Go to step 4.
NO
- Secondary HO2S (Sensor 2) internal heater resistance check
-1. Disconnect the following connectors.
Front secondary HO2S (Sensor 2) 4P connector Rear secondary HO2S (Sensor 2) 4P connector - 2. At the sensor side, measure the resistance between test points 1 and 2.
Test condition Vehicle OFF (LOCK) mode
Relay circuit board: disconnected Front and rear secondary HO2S (Sensor 2) 4P connectors: disconnected Test point 1 Secondary HO2S (Sensor 2) 4P connector No. 3 (secondary HO2S (Sensor 2) side) Test point 2 Secondary HO2S (Sensor 2) 4P connector No. 4 (secondary HO2S (Sensor 2) side) Rear bank (Bank 1):
Front bank (Bank 2):
Is there 5.4-7.3 Ω at room temperature?
YES
Go to step 5.
NO
- Secondary HO2S (Sensor 2) internal circuit check
-1. At the sensor side, check for continuity under the following conditions.
Test condition Vehicle OFF (LOCK) mode
Relay circuit board: disconnected Front and rear secondary HO2S (Sensor 2) 4P connectors: disconnected Test point 1 Rear secondary HO2S (Bank 1, Sensor 2) 4P connector No. 3 and No. 4 (secondary HO2S (Sensor 2) side) Front secondary HO2S (Bank 2, Sensor 2) 4P connector No. 3 and No. 4 (secondary HO2S (Sensor 2) side) * Test point 2 Body ground Rear bank (Bank 1):
Front bank (Bank 2):
Is there continuity?
YES
Replace secondary HO2S (Sensor 2) .
NO
Go to step 6.
- Shorted wire check (SO2HT B1 (SO2HT B2) * line):
- 1.Jump the SCS line with the HDS, and wait more than 1 minute.
- 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
Relay circuit board: disconnected Front and rear secondary HO2S (Sensor 2) 4P connectors: disconnected PCM connector C (51P): disconnected Test point 1
PCM connector C (51P) No. 5 - Refer to:
PCM Connector for Inputs and Outputs (9-Speed A/T) (2016 2017 2018), or
PCM Connector for Inputs and Outputs (6-Speed A/T) (2016 2017 2018 2019 2020)PCM connector C (51P) No. 7 * - Refer to:
PCM Connector for Inputs and Outputs (6-Speed A/T) (2016 2017 2018 2019 2020), or
PCM Connector for Inputs and Outputs (9-Speed A/T) (2016 2017 2018)Test point 2 Body ground Is there continuity?
YES
Repair a short in the SO2HT B1 (SO2HT B2) * wire between the PCM (C5 (C7) *) and secondary HO2S (Sensor 2).
NO
The SO2HT B1 (SO2HT B2) * wire is not shorted. Go to step 7.
- Open wire check (SO2HT B1 (SO2HT B2) * line):
- 1.Check for continuity between test points 1 and 2.
Test condition Vehicle OFF (LOCK) mode Relay circuit board: disconnected Front and rear secondary HO2S (Sensor 2) 4P connectors: disconnected PCM connector C (51P): disconnected Test point 1 Rear secondary HO2S (Bank 1, Sensor 2) 4P connector No. 4 Front secondary HO2S (Bank 2, Sensor 2) 4P connector No. 3 * Test point 2 PCM connector C (51P) No. 5 - Refer to:
PCM Connector for Inputs and Outputs (9-Speed A/T) (2016 2017 2018), or
PCM Connector for Inputs and Outputs (6-Speed A/T) (2016 2017 2018 2019 2020)PCM connector C (51P) No. 7 * - Refer to:
PCM Connector for Inputs and Outputs (6-Speed A/T) (2016 2017 2018 2019 2020), or
PCM Connector for Inputs and Outputs (9-Speed A/T) (2016 2017 2018)Rear bank (Bank 1):
Front bank (Bank 2):
Is there continuity?
YES
The SO2HT B1 (SO2HT B2) * wire is OK. Go to step 8.
NO
Repair an open in the SO2HT B1 (SO2HT B2) * wire between the PCM (C5 (C7) *) and secondary HO2S (Sensor 2).
- Open wire check (IG (LAF O2)/FI SUB line)
-1. Check for continuity between test points 1 and 2.
Test condition Vehicle OFF (LOCK) mode
Relay circuit board: disconnected Front and rear secondary HO2S (Sensor 2) 4P connectors: disconnected PCM connector C (51P): disconnected Test point 1 Relay circuit board connector A (10P) No. 4 Test point 2 Rear secondary HO2S (Bank 1, Sensor 2) 4P connector No. 3 Front secondary HO2S (Bank 2, Sensor 2) 4P connector No. 4 * Rear bank (Bank 1):
Front bank (Bank 2):
Is there continuity?
YES
The IG (LAF O2)/FI SUB is not open. Go to step 9.
NO
Repair an open in the IG (LAF O2)/FI SUB wire between secondary HO2S (Sensor 2) and the relay circuit board.
- Open wire check (LAF RLY line)
-1. Disconnect the following connector.
PCM connector A (51P) - 2. Check for continuity between test points 1 and 2.
Test condition Vehicle OFF (LOCK) mode
Relay circuit board: disconnected Front and rear secondary HO2S (Sensor 2) 4P connectors: disconnected PCM connector C (51P): disconnected PCM connector A (51P): disconnected Test point 1 Relay circuit board connector A (10P) No. 6 Test point 2 PCM connector A (51P) No. 14 - Refer to:
PCM Connector for Inputs and Outputs (9-Speed A/T) (2016 2017 2018), or
PCM Connector for Inputs and Outputs (6-Speed A/T) (2016 2017 2018 2019 2020)Is there continuity?
YES
The LAF RLY wire is OK. Check for any authorized service information related to the DTCs or symptoms you are troubleshooting or substitute a known-good PCM - Refer to: PCM Removal and Installation (6-Speed A/T), (9-Speed A/T 2016 2017 2018) .
NO
Repair an open in the LAF RLY wire between the PCM (A14) and the relay circuit board.
- Shorted wire check (IG (LAF O2)/FI SUB line)
-1. Disconnect the following connectors.
Relay circuit board connector A (10P) Front and rear secondary HO2S (Sensor 2) 4P connectors Front and rear A/F sensor (Sensor 1) 6P connectors EVAP canister vent shut valve 2P connector (USA and Canada models) - 2. Check for continuity between test points 1 and 2.
Test condition Vehicle OFF (LOCK) mode Relay circuit board: disconnected Front and rear secondary HO2S (Sensor 2) 4P connectors: disconnected Front and rear A/F sensor (Sensor 1) 6P connectors: disconnected EVAP canister vent shut valve 2P connector (USA and Canada models): disconnected Test point 1 Rear secondary HO2S (Bank 1, Sensor 2) 4P connector No. 3 Front secondary HO2S (Bank 2, Sensor 2) 4P connector No. 4 * Test point 2 Body ground Rear bank (Bank 1):
Front bank (Bank 2):
Is there continuity?
YES
Repair a short in the IG (LAF O2)/FI SUB wire between the relay circuit board, secondary HO2S (Sensor 2), and the EVAP canister vent shut valve (USA and Canada models). Also replace the No. A22 (15 A) fuse in the under-hood fuse/relay box.
NO
The IG (LAF O2)/FI SUB wire is OK. Check the under-hood fuse/relay box, and replace it if needed. Also replace the No. A22 (15 A) fuse.