DTC P0138
DTC P0138 : Secondary HO2S (Sensor 2) Circuit High Voltage
Before you troubleshoot, review the general troubleshooting information .
| DTC Description | Confirmed DTC | Pending DTC |
|---|---|---|
| P0138 Secondary HO2S (Sensor 2) Circuit High Voltage |
DTC (PGM-FI)
- Problem verification
-1. Turn the vehicle to the ON mode.
-2. Clear the DTC with the HDS.
-3. Enter the maintenance mode, then start the engine .
-4. Hold the engine speed at 3, 000 rpm without load (in P or N) until the radiator fan comes on, then let it idle.
-5. Check for Pending or Confirmed DTCs with the HDS.
DTC Description Confirmed DTC Pending DTC P0138 Secondary HO2S (Sensor 2) Circuit High Voltage Is DTC P0138 is 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 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 .
- Determine possible failure area (short to power in SO2SG/SO2_SG line, others)
-1. Turn the vehicle to the OFF (LOCK) mode.
-2. Disconnect the following connector.
Secondary HO2S (Sensor 2) 4P connector -3. Connect terminals A and B with a jumper wire.
Terminal A Secondary HO2S (Sensor 2) 4P connector (male terminals) No. 1: Terminal B Secondary HO2S (Sensor 2) 4P connector (male terminals) No. 2: -4. Turn the vehicle to the ON mode.
-5. Check the parameter (s) below with the HDS.
Signal Threshold Current conditions Values Unit Values Unit HO2S S2 More than 3.22 V Do the current condition (s) match the threshold?
YES
Go to step 3.
NO
Go to step 5.
- Open wire check (SO2SG/SO2_SG line)
-1. Turn the vehicle to the OFF (LOCK) mode.
-2. Remove the jumper wire from the secondary HO2S (Sensor 2) 4P connector.
-3. Connect terminals A and B with a jumper wire.
Terminal A Secondary HO2S (Sensor 2) 4P connector (male terminals) No. 1: Terminal B Body ground -4. Turn the vehicle to the ON mode.
-5. Check the parameter (s) below with the HDS.
Signal Threshold Current conditions Values Unit Values Unit HO2S S2 More than 3.22 V Do the current condition (s) match the threshold?
YES
The SO2SG/SO2_SG wire is OK. Go to step 4.
NO
Repair an open in the SO2SG/SO2_SG wire between the PCM (A48) and the secondary HO2S (Sensor 2).
- Open wire check (SO2 line)
-1. Turn the vehicle to the OFF (LOCK) mode.
-2. Jump the SCS line with the HDS, and wait more than 1 minute.
-3. Disconnect the following connector.
PCM connector A (50P) -4. Measure the resistance between test points 1 and 2.
Test condition Vehicle OFF (LOCK) mode Secondary HO2S (Sensor 2) 4P connector: disconnected PCM connector A (50P) : disconnected Secondary HO2S (Sensor 2) 4P connector No. 1: jumped to body ground Test point 1 PCM connector A (50P) No. 47 Test point 2 Body ground Is there 1.0 Ω or less?
YES
The SO2 wire is OK. Check for any authorized service information related to the DTCs or symptoms you are troubleshooting, or substitute a known-good PCM .
NO
Repair an open in the SO2 wire between the PCM (A47) and the secondary HO2S (Sensor 2).
- Shorted wire check (SO2SG/SO2_SG line to power)
-1. Turn the vehicle to the OFF (LOCK) mode.
-2. Remove the jumper wire from the secondary HO2S (Sensor 2) 4P connector.
-3. Jump the SCS line with the HDS, and wait more than 1 minute.
-4. Disconnect the following connector.
PCM connector A (50P) -5. Turn the vehicle to the ON mode.
-6. Measure the voltage between test points 1 and 2.
Test condition Vehicle ON mode Secondary HO2S (Sensor 2) 4P connector: disconnected PCM connector A (50P) : disconnected Test point 1 PCM connector A (50P) No. 48 Test point 2 Body ground Is there about 5 V or more?
YES
Repair a short to power in the SO2SG/SO2_SG wire between the PCM (A48) and the secondary HO2S (Sensor 2).
NO
The SO2SG/SO2_SG wire is OK. Replace the secondary HO2S (Sensor 2) .