02 Sensor 1/2 Circuit High

(P0138) 02 SENSOR 1/2 CIRCUIT HIGH





When Monitored and Set Condition
^ When Monitored: With the engine running between 1000 and 2000 RPM, engine load between 15% to 50%, closed loop mode, the three way catalytic converter temperature is greater than 380°C (716°F), and the 02 sensor heater must be ON for at least 220 seconds to enable the signal inactive portion of the test.
^ Set Condition: 02 Sensor voltage is greater than 1.5 volts for approximately 5 seconds.

POSSIBLE CAUSES
- 02 SENSOR SIGNAL CIRCUIT SHORT TO VOLTAGE
- ENGINE EXHAUST LEAK
- 02 SENSOR
- POWERTRAIN CONTROL MODULE



Diagnostic Test
1. CHECK FOR CURRENT DTC





Turn the ignition on. With the DRBIII, read PCM DTCs.
Is this DTC present?
Yes >> For complete diagnosis of this DTC, refer to (P0131) 02 SENSOR 1/1 CIRCUIT LOW. P0131
No >> Go To 2

2. INTERMITTENT WIRING AND CONNECTORS
The conditions necessary to set this DTC are not present at this time.

Note: Check connectors - Clean/repair as necessary. Poor pin to terminal connections can set DTCs. Using the wiring diagram/schematic as a guide, inspect the wiring and connectors specific to this DTC. Wiggle the wires while checking for shorts and open circuits.

Note: Check for any Technical Service Bulletins that may apply.

Were there any problems found?
Yes >> Repair as necessary. Perform POWERTRAIN VERIFICATION TEST - VER 2 Powertrain Verification Test - Ver 2.
No >> The condition that caused this DTC to set is currently not present. Inspect the related wiring harness for a possible intermittent condition.