DTC Troubleshooting: P0138 (63)
DTC P0138:
 Secondary HO2S (Sensor 2) Circuit High Voltage
NOTE: Before you troubleshoot, record all freeze data and any on-board snapshot, and review the general troubleshooting information.
  1. Turn the ignition switch to ON (II).
  1. Clear the DTC with the HDS.
  1. Start the engine. Hold the engine speed at 3,000 rpm (min −1 ) without load (A/T in P or N, M/T in neutral) until the radiator fan comes on, then let it idle.
  1. Check the HO2S S2 in the DATA LIST with the HDS.
Does the voltage stay at 1.27 V or more?
YES -
Go to Step 5 .
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 ECM/PCM.■
  1. Turn the ignition switch to LOCK (0).
  1. Disconnect the secondary HO2S (Sensor 2) 4P connector.
  1. Connect secondary HO2S (Sensor 2) 4P connector terminals No. 1 and No. 2 with a jumper wire.
  1. Turn the ignition switch to ON (II).
  1. Check the HO2S S2 in the DATA LIST with the HDS.
Does the voltage stay at 1.27 V or more?
YES -
Go to Step 10 .
NO -
Go to Step 19 .
  1. Turn the ignition switch to LOCK (0).
  1. Remove the jumper wire from the secondary HO2S (Sensor 2) 4P connector.