DTC P0137, P0157 (19-21 9-Speed A/T)
DTC P0137 : Rear Secondary Heated Oxygen Sensor (Secondary HO2S (Bank 1, Sensor 2)) Circuit Low Voltage
DTC P0157 : Front Secondary Heated Oxygen Sensor (Secondary HO2S (Bank 2, Sensor 2)) Circuit Low Voltage
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 |
|---|---|---|
| P0137 Rear Secondary Heated Oxygen Sensor (Secondary HO2S (Bank 1, Sensor 2)) Circuit Low Voltage | ||
| P0157 Front Secondary Heated Oxygen Sensor (Secondary HO2S (Bank 2, Sensor 2)) Circuit Low Voltage |
DTC (PGM-FI)
- Problem verification
-1. Turn the vehicle to the ON mode.
- 2. Clear the DTC with the HDS.
- 3. Turn the vehicle to the OFF (LOCK) mode.
- 4. Start the engine.
- 5. Hold the engine speed at 3, 000 rpm without load (in P or N) until the radiator fan comes on.
- 6. Monitor the OBD STATUS for DTC P0137 and/or P0157 * in the DTCs MENU with the HDS.
DTC Description OBD STATUS P0137 Rear Secondary Heated Oxygen Sensor (Secondary HO2S (Bank 1, Sensor 2)) Circuit Low Voltage P0157 Front Secondary Heated Oxygen Sensor (Secondary HO2S (Bank 2, Sensor 2)) Circuit Low Voltage Does the HDS indicate FAILED?
YES
The failure is duplicated. Go to step 2.
NO
If the HDS indicates PASSED, 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 on-board snapshot of this DTC is recorded, try to reproduce the failure under the same conditions with the on-board snapshot - Refer to: How to Troubleshoot the Fuel and Emissions Systems If the HDS indicates EXECUTING, keep idling until a result comes on. If the HDS indicates OUT OF CONDITION, go to step 1-5 and recheck.
- Determine possible failure area (secondary HO2S (Sensor 2), others)
-1. Turn the vehicle to the OFF (LOCK) mode.
- 2. Disconnect the following connector.
Secondary HO2S (Sensor 2) 4P connector - 3. Turn the vehicle to the ON mode.
- 4. Check the parameter (s) below with the HDS.
Signal Threshold Current conditions Values Unit Values Unit HO2S B1 S2 Less than 0.18 V HO2S B2 S2 Less than 0.18 V Do the current condition (s) match the threshold?
YES
Go to step 3.
NO
- Determine possible failure area (short in SO2B1 (SO2B2) * line, short in SO2SGB1 (SO2SGB2) * line):
- 1.Turn the vehicle to the OFF (LOCK) mode.
- 2. Check for continuity between test points 1 and 2.
Test condition Vehicle OFF (LOCK) mode Secondary HO2S (Sensor 2) 4P connector: disconnected Test point 1
Rear secondary HO2S (Bank 1, Sensor 2) 4P connector (female terminals) No. 2: Front secondary HO2S (Bank 2, Sensor 2) 4P connector (male terminals) No. 1*: Test point 2 Body ground Is there continuity?
YES
Go to step 4.
NO
Go to step 5.
- Shorted wire check (SO2B1 (SO2B2) * line):
- 1.Jump the SCS line with the HDS, and wait more than 1 minute.
- 2. Disconnect the following connector.
PCM connector E (80P) - 3. Check for continuity between test points 1 and 2.
Test condition Vehicle OFF (LOCK) mode
Secondary HO2S (Sensor 2) 4P connector: disconnected PCM connector E (80P): disconnected Test point 1
Rear secondary HO2S (Bank 1, Sensor 2) 4P connector (female terminals) No. 2: Front secondary HO2S (Bank 2, Sensor 2) 4P connector (male terminals) No. 1*: Test point 2 Body ground Is there continuity?
YES
Repair a short in the SO2B1 (SO2B2) * wire between the PCM (E56 (E74) *) and secondary HO2S (Sensor 2).
NO
The SO2B1 (SO2B2) * 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 (9-Speed A/T 2019 2020 2021) , then recheck. If DTC P0137 and/or P0157* goes away and the PCM was substituted, replace the original PCM - Refer to: PCM Removal and Installation (9-Speed A/T 2019 2020 2021) .
- Shorted wire check (SO2SGB1 (SO2SGB2) * line):
- 1.Jump the SCS line with the HDS, and wait more than 1 minute.
- 2. Disconnect the following connector.
PCM connector E (80P) - 3. Check for continuity between test points 1 and 2.
Test condition Vehicle OFF (LOCK) mode
Secondary HO2S (Sensor 2) 4P connector: disconnected PCM connector E (80P): disconnected Test point 1
Rear secondary HO2S (Bank 1, Sensor 2) 4P connector (female terminals) No. 1: Front secondary HO2S (Bank 2, Sensor 2) 4P connector (male terminals) No. 2*: Test point 2 Body ground Is there continuity?
YES
Repair a short in the SO2SGB1 (SO2SGB2) * wire between the PCM (E57 (E75) *) and secondary HO2S (Sensor 2).
NO
The SO2SGB1 (SO2SGB2) * 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 (9-Speed A/T 2019 2020 2021) , then recheck. If DTC P0137 and/or P0157* goes away and the PCM was substituted, replace the original PCM - Refer to: PCM Removal and Installation (9-Speed A/T 2019 2020 2021) .