DTC P0135 HEATED OXYGEN SENSOR 1 HEATER (FRONT); Diagnostic Procedure
EF & EC-7127prose procedureP0135 heater ground side: HO2S1 connector terminal 4 ↔ ECM terminal 11 (wire L per terminals table earlier was sensor signal ground; here it's the heater ground return).
CG10, CGA3
Diagnostic Procedure
Step 1 — CHECK POWER SUPPLY
- 1Turn ignition switch "OFF".
- 2Disconnect heated oxygen sensor 1 (front) harness connector. (See NEF153A)
- 3Turn ignition switch "ON".
- 4Check voltage between terminal 3 and ground with CONSULT-II or tester. Voltage: Battery voltage
- 5OK or NG: - OK → GO TO 2. - NG → Repair open circuit to ground or short to power in harness connectors.
Step 2 — CHECK GROUND CIRCUIT
- 1Turn ignition switch "OFF".
- 2Disconnect ECM harness connector.
- 3Check harness continuity between heated oxygen sensor 1 (front) harness connector terminal 4 and ECM terminal 11. Refer to wiring diagram. Continuity should 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.
Step 3 — CHECK HEATED OXYGEN SENSOR 1 HEATER (FRONT)
- 1Refer to "Component Inspection", EC-7128.
- 2OK or NG: - OK → GO TO 4. - NG → Replace heated oxygen sensor 1 (front).
Step 4 — CHECK INTERMITTENT INCIDENT
- 1Perform "TROUBLE DIAGNOSIS FOR INTERMITTENT INCIDENT", EC-7070.
- 2→ INSPECTION END.
See also
EC-7128 · EC-7070