DTC P0137: 1/2 O2 Sensor Volts Shorted To Ground
NOTE:
For connector terminal ID, see CONNECTOR IDENTIFICATION
. For wiring diagram, see WIRING DIAGRAMS article.
NOTE:
The 1/2 O2 sensor is referred to as downstream oxygen sensor in this test. Downstream oxygen sensor operation is monitored with engine coolant temperature more than 170°F (76.7°C) after ignition was last turned on, after a cold start, engine coolant temperature is less than 98°F (36.6°C) and ambient/battery temperature sensor reading is within 27°F (-2.7°C) of engine coolant temperature. DTC may be stored in Powertrain Control Module (PCM) if downstream oxygen sensor signal voltage is less than .156 volt for 28 seconds after engine is started. Possible causes are; defective downstream oxygen sensor, defective PCM, or defective connectors or wiring.
- Turn ignition on with engine off. Using scan tool, read downstream oxygen sensor voltage. Downstream oxygen sensor voltage may also be referred to as 1/2 O2 sensor voltage. If downstream oxygen sensor voltage is less than .16 volt, go to next step. If downstream oxygen sensor voltage is .16 volt or more, conditions required to set DTC are not present at this time. Test is complete.
- Turn ignition off. Disconnect downstream oxygen sensor connector. Downstream oxygen sensor is located on exhaust pipe, behind catalytic converter. Turn ignition on with engine off. Using scan tool, read downstream oxygen sensor voltage. If downstream oxygen sensor voltage is less than .16 volt, go to next step. If downstream oxygen sensor voltage is .16 volt or more, replace downstream oxygen sensor. Perform TEST VER-5A .
- Turn ignition off. Disconnect PCM connectors. PCM is located at driver's side front corner of engine compartment, just below air cleaner assembly.
- Ensure downstream oxygen sensor and PCM connectors are disconnected. Using ohmmeter, check resistance between ground and terminal No. 1 (Tan/White wire) at wiring harness side of downstream oxygen sensor connector. If resistance is 5 ohms or more, go to next step. If resistance is less than 5 ohms, repair short to ground on Tan/White wire between PCM and downstream oxygen sensor. Perform TEST VER-5A .
- Ensure downstream oxygen sensor and PCM connectors are disconnected. Using ohmmeter, check resistance between terminals No. 1 (Tan/White wire) and No. 3 (Black/Light Blue wire) at wiring harness side of downstream oxygen sensor connector. If resistance is 5 ohms or more, replace PCM. Perform TEST VER-5A . If resistance is less than 5 ohms, repair Tan/White wire and Black/Light Blue wire between PCM and downstream oxygen sensor as they are shorted together. Perform TEST VER-5A .