DTC P0141, P0161
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, or How to Troubleshoot the Brake Booster Pressure Monitoring System (2016 2017 2018 2019 2020), or How to Troubleshoot the Fuel and Emissions Systems(With Auto Idle Stop System) (2016), or How to Troubleshoot the A/T System (2014 2015) .
- 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.
- 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. C8 (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 check
-1. Remove the PGM-FI subrelay (A) from the under-hood fuse/relay box.
- 2. Test the PGM-FI subrelay.
Is the relay OK?
YES
The PGM-FI subrelay is OK. Go to step 4.
NO
Replace the PGM-FI subrelay.
- 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 PGM-FI subrelay: disconnected Front and rear secondary HO2S (Sensor 2) 4P connectors: disconnected Test circuit SO2HT B1 (SO2HT B2) *, IG(LAF O2) 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 5.4-6.6 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 PGM-FI subrelay: disconnected Front and rear secondary HO2S (Sensor 2) 4P connectors: disconnected Test circuit SO2HT B1 (SO2HT B2) * Test point 1 Rear secondary HO2S (Bank 1, Sensor 2) 4P connector No. 4 (secondary HO2S (Sensor 2) side) Front secondary HO2S (Bank 2, Sensor 2) 4P connector No. 3 (secondary HO2S (Sensor 2) side)* Test point 2 Body ground Test circuit IG(LAF O2) Test point 1 Rear secondary HO2S (Bank 1, Sensor 2) 4P connector No. 3 (secondary HO2S (Sensor 2) side) Front secondary HO2S (Bank 2, Sensor 2) 4P connector 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.
- 2. Disconnect the following connector.
- 3. Check for continuity between test points 1 and 2.
Test condition Vehicle OFF (LOCK) mode PGM-FI subrelay: disconnected Front and rear secondary HO2S (Sensor 2) 4P connectors: disconnected PCM connector C (51P): disconnected Test circuit SO2HT B1 (SO2HT B2) * Test point 1 PCM connector C (51P) No. 5 (PUR) PCM connector C (51P) No. 7 (RED) * 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 PGM-FI subrelay: disconnected Front and rear secondary HO2S (Sensor 2) 4P connectors: disconnected PCM connector C (51P): disconnected Test circuit SO2HT B1 (SO2HT B2) * Test point 1 Rear secondary HO2S (Bank 1, Sensor 2) 4P connector No. 4 (PUR) Front secondary HO2S (Bank 2, Sensor 2) 4P connector No. 3 (RED) * Test point 2 PCM connector C (51P) No. 5 (PUR) PCM connector C (51P) No. 7 (RED) * 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 PGM-FI subrelay: disconnected Front and rear secondary HO2S (Sensor 2) 4P connectors: disconnected PCM connector C (51P): disconnected Test circuit IG(LAF O2)/FI SUB Test point 1 PGM-FI subrelay 4P socket No. 2 Test point 2 Rear secondary HO2S (Bank 1, Sensor 2) 4P connector No. 3 (PNK) Front secondary HO2S (Bank 2, Sensor 2) 4P connector No. 4 (PNK) * Rear bank (Bank 1):
Front bank (Bank 2):
Are 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 PGM-FI subrelay.
- Open wire check (LAF RLY line)
-1. Disconnect the following connector.
- 2. Check for continuity between test points 1 and 2.
Test condition Vehicle OFF (LOCK) mode PGM-FI subrelay: disconnected Front and rear secondary HO2S (Sensor 2) 4P connectors: disconnected PCM connector C (51P): disconnected PCM connector A (51P): disconnected Test circuit LAF RLY Test point 1 PGM-FI subrelay 4P socket No. 4 Test point 2 PCM connector A (51P) No. 14 (PNK) Is there continuity?
YES
The LAF RLY wire is OK. Update the PCM if it does not have the latest software, or substitute a known-good PCM - Refer to: PCM Removal and Installation (2014 2015), or PCM Removal and Installation (2016) .
NO
Repair an open in the LAF RLY wire between the PGM-FI subrelay and the PCM (A14).
- Shorted wire check (IG(LAF O2)/FI SUB line)
-1. Remove the PGM-FI subrelay (A) and the No. C28 (7.5 A) fuse from the under-hood fuse/relay box.
- 2. Disconnect the following connectors.
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 - 3. Check for continuity between test points 1 and 2.
Test condition Vehicle OFF (LOCK) mode PGM-FI subrelay: disconnected No. C8 (15 A) fuse: 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: disconnected Test circuit IG(LAF O2)/FI SUB Test point 1 Rear secondary HO2S (Bank 1, Sensor 2) 4P connector No. 3 (PNK) Front secondary HO2S (Bank 2, Sensor 2) 4P connector No. 4 (PNK)* 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 PGM-FI subrelay, secondary HO2S (Sensor 2), the A/F sensor (Sensor 1), and the PCM. Also replace the No. C8 (15 A) fuse.
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. C8 (15 A) fuse.