DTC P0131 HEATED OXYGEN SENSOR 1 (FRONT) (LOW VOLTAGE); Overall Function Check (Cont'd); Diagnostic Procedure
EF & EC-7107prose procedureOverall Function Check minimum voltage spec here says "over 0.1V at least one time" (P0131 LOW VOLTAGE-specific) vs P0130's "below 0.3V" — preserved verbatim.
CG10, CGA3
Overall Function Check (Cont'd)
1 time: 0 - 0.3V → 0.6 - 1.0V → 0 - 0.3V
2 times: 0 - 0.3V → 0.6 - 1.0V → 0 - 0.3V → 0.6 - 1.0V → 0 - 0.3V
- The maximum voltage is over 0.6V at least one time.
- The minimum voltage is over 0.1V at least one time.
4) If NG, go to "Diagnostic Procedure", below.
Diagnostic Procedure
Step 1 — INSPECTION START
- 1Turn ignition switch "OFF".
- 2Loosen and retighten engine ground screws. (See NEF147A)
- 3Disconnect heated oxygen sensor 1 (front) harness connector. (See NEF153A)
- 4→ GO TO 2.
Step 2 — CHECK INPUT SIGNAL CIRCUIT
- 1Disconnect ECM harness connector.
- 2Check harness continuity between ECM terminal 12 and heated oxygen sensor 1 (front) harness connector terminal 1. Refer to wiring diagram. Continuity should exist.
- 3Check harness continuity between ECM terminal 12 (or terminal 1) and ground. Continuity should not exist.
- 4Also check harness for short to power.
- 5OK or NG: - OK → GO TO 3. - NG → Repair open circuit or short to ground or short to power in harness or connectors.