DTC P0140 HEATED OXYGEN SENSOR 2 (REAR) (PLAUSIBILITY); Diagnostic Procedure (Cont'd); Component Inspection

EF & EC-7147prose procedure

Second P0140 Diagnostic Procedure (Cont'd) — concludes the second P0140 PLAUSIBILITY sequence (NO-ACTIVITY waveform variant from EC-7144).

Continued from EF & EC-7146

CG10, CGA3

Diagnostic Procedure (Cont'd)

Step 4 — CHECK GROUND CIRCUIT

1
Check harness continuity between heated oxygen sensor 2 (rear) harness connector terminal 4 and engine ground. Refer to wiring diagram. Continuity should exist.
2
Also check harness for short to ground and short to power.
3
OK or NG: - OK → GO TO 5. - NG → Repair open circuit or short to ground or short to power in harness or connectors.

Step 5 — CHECK HARNESS CONNECTOR

1
Check heated oxygen sensor 2 (rear) harness connector for water. Water should not exist.
2
OK or NG: - OK → GO TO 6. - NG → Repair or replace harness connector.

Step 6 — CHECK HEATED OXYGEN SENSOR 2 (REAR)

1
Refer to "Component Inspection", below.
2
OK or NG: - OK → GO TO 7. - NG → Replace heated oxygen sensor 2 (rear).

Step 7 — CHECK INTERMITTENT INCIDENT

1
Perform "TROUBLE DIAGNOSIS FOR INTERMITTENT INCIDENT", EC-7070.
2
▶ INSPECTION END.

Component Inspection

HEATED OXYGEN SENSOR 2 (REAR)

With CONSULT-II

1
Start engine and warm up engine to normal operating temperature.
2
Stop engine and wait at least 1 second.
3
Turn ignition switch "ON".
4
Select "FUEL INJECTION" in "ACTIVE TEST" mode, and select "HO2S2 (B1)" as the monitor item with CONSULT-II.
5
Check "HO2S2 (B1)" at idle speed when adjusting "FUEL INJECTION" to ±25%. "HO2S2 (B1)" should be above 0.68V at least once when the "FUEL INJECTION" is +25%. "HO2S2 (B1)" should be below 0.56V at least once when the "FUEL INJECTION" is -25%.

CAUTION

Discard any heated oxygen sensor which has been dropped from a height of more than 0.5 m (19.7 in) onto a hard surface such as a concrete floor; use a new one.

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