DTC P0137: 1/2 O2 Sensor Shorted To Ground: Testing
- Turn ignition on. Using scan tool, read DTCs. If GOOD TRIP is displayed and equal to zero, go to next step. If GOOD TRIP is not displayed and equal to zero, go to step 6 .
- Disconnect 1/2 HO2S harness connector. Using scan tool, read 1/2 HO2S voltage. If voltage is .16 volt or less, go to next step. If voltage is more than .16 volt, check for miswiring in 1/2 HO2S harness connector. See Fig 1 . Repair connector as necessary. If connector is okay, replace HO2S.
- Turn ignition off. Disconnect PCM harness connectors. See Figure . Measure resistance between signal circuit (Tan/White wire) and sensor ground circuit (Black/Orange wire) at 1/2 HO2S harness connector. If resistance is 5 ohms or more, go to next step. If resistance is less than 5 ohms, repair short between signal circuit and sensor ground circuit.
- Measure resistance between engine ground and signal circuit (Tan/White wire) at 1/2 HO2S harness connector. If resistance is 5 ohms or more, go to next step. If resistance is less than 5 ohms, repair short to ground in signal circuit.
- If no other possible causes are remaining, replace PCM.
- Conditions that set DTC are not present at this time. Perform the following to help identify intermittent condition:
- With engine running at normal operating temperature, wiggle related wiring harness while monitoring related parameters on scan tool. If voltage changes or DTC sets while wiggling wiring harness, repair connectors or wiring harness where wiggling caused voltage to change or DTC to set.
- Review freeze frame information on scan tool. Duplicate conditions present when DTC was set.
- Refer to any Technical Service Bulletins (TSBs) that may apply.
- Visually inspect related wiring harness. Check for chafed, pierced, pinched or partially broken wires.
- Visually inspect related wiring harness connectors. Check for broken, bent, pushed out or corroded terminals.
If a problem is found, repair as necessary. If no problems are found, test is complete.