02 Sensor 2/2 Above Threshold
(P0137) 02 SENSOR 2/2 ABOVE THRESHOLD
When Monitored and Set Condition
^ When Monitored: Start and drive vehicle greater than 32 km/h (20 MPH) and less than 89 km/h (55 MPH). Throttle open for a minimum 120 seconds. Coolant Temp greater than 70°C (158°F) and Catalytic Converter Temperature greater than 600°C (1112°F).
^ Set Condition: The 02 sensor voltage switches only 11 times or less from lean to rich within 20 seconds during monitoring. Two Trip Fault.
POSSIBLE CAUSES
- EXHAUST LEAK
- 02 SENSOR SIGNAL CIRCUIT SHORT TO VOLTAGE
- 02 SENSOR SIGNAL CIRCUIT SHORT TO GROUND
- 02 SENSOR SIGNAL CIRCUIT OPEN
- 02 SENSOR GROUND CIRCUIT SHORT TO VOLTAGE
- 02 SENSOR GROUND CIRCUIT SHORT TO GROUND
- 02 SENSOR GROUND CIRCUIT OPEN
- 02 SENSOR
Diagnostic Test
1. PRE-DIAGNOSTIC CHECK OUT
Note: Always perform diagnostics with a fully charged battery.
Note: Check connectors - Clean/repair as necessary. Poor pin to terminal connections can set DTCs.
Note: Check for applicable TSBs related to the problem. Turn the ignition on. With the DRBIII, read PCM DTCs. Using the wiring diagram/schematic as a guide, inspect the wiring and connectors. Repair as necessary. Perform this procedure prior to symptom diagnosis.
Continue
Go To 2
2. CHECK FOR CURRENT DTC
Note: It is important to perform the diagnostics on the 02 Sensor that set the DTC.
Note: Check for contaminates that may have damaged the 02 Sensor: contaminated fuel, unapproved silicone, oil and coolant.
Note: If the PCM detects and stores a DTC, the PCM also stores the engine/vehicle operating conditions under which the DTC was set. Some of these conditions are displayed on the DRBIII at the same time the DTC is displayed.
Note: Before erasing stored DTCs, record these conditions. Attempting to duplicate these conditions may assist when checking for an active DTC.
Turn the ignition on.
With the DRBIII, erase PCM DTCs.
Note: It maybe necessary to road test the vehicle for this DTC to set.
With the DRBIII, read PCM DTCs.
Did this DTC set again?
Yes >> Go To 3
No >> Go To 6
3. EXHAUST LEAK
Start the engine. Inspect the exhaust system for leaks between the engine and the 02 Sensors.
Are there any exhaust leaks?
Yes >> Repair or replace the leaking exhaust parts as necessary. Perform POWERTRAIN VERIFICATION TEST - VER 2 Powertrain Verification Test - Ver 2.
No >> Go To 4
4. 02 SIGNAL CIRCUIT
Turn the ignition off
Disconnect the 02 Sensor harness connector.
Note: Check connectors - Clean/repair as necessary. Turn the ignition on.
Measure the voltage of the 02 Signal circuit at the 02 Sensor harness connector.
Is the voltage approximately 0.47 volt?
Yes >> Go To 5
No >> Check the 02 Signal circuit for damage, short to ground, open, or short to voltage. If OK, replace and program the Powertrain Control Module. Perform POWERTRAIN VERIFICATION TEST - VER 2 Powertrain Verification Test - Ver 2.
5. SENSOR GROUND CIRCUIT
Turn the ignition off. Disconnect the PCM harness connectors.
Note: Check connectors - Clean/repair as necessary.
Measure the resistance of the Sensor Ground circuit from the 02 Sensor harness connector to the PCM harness connector.
Is the resistance below 5.0 ohms?
Yes >> Replace the Oxygen Sensor. Perform POWERTRAIN VERIFICATION TEST - VER 2 Powertrain Verification Test - Ver 2.
No >> Check the Sensor Ground circuit for damage, short to ground, open, or short to voltage. If OK, replace and pro gram the Powertrain Control Module. Perform POWERTRAIN VERIFICATION TEST - VER 2 Powertrain Verification Test - Ver 2.
6. 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.