TROUBLE DIAGNOSES - Diagnostic Procedure 24 (Cont'd)
EF & EC-4016flowchartDiagnostic Procedure 24 (Cont'd)
1
INSPECTION START
2
CHECK POWER SUPPLY. 1) Disconnect mass air flow sensor harness connector. 2) Turn ignition switch ON. 3) Check voltage between terminal c and ground. Voltage: Battery voltage
NG
Check the following: Harness connectors F21, M17 (LHD models); Harness connectors F28, M23 (RHD models); Harness connectors M59, E55 (LHD models); Harness connectors M3, E1 (RHD models); Harness continuity between mass air flow sensor and ECCS relay; 25A fusible link; Harness continuity between 25A fusible link and ECCS relay. If NG, replace fusible link or repair harness or connectors.
Check the following: Harness connectors F21, M17 (LHD models); Harness connectors F28, M23 (RHD models); Harness connectors M59, E55 (LHD models); Harness connectors M3, E1 (RHD models); Harness continuity between mass air flow sensor and ECCS relay; 25A fusible link; Harness continuity between 25A fusible link and ECCS relay. If NG, replace fusible link or repair harness or connectors.
OK
3
CHECK GROUND CIRCUIT. 1) Turn ignition switch OFF. 2) Check harness continuity between terminal b and engine ground. Continuity should exist.
NG
Repair harness or connectors.
OK
4
CHECK INPUT SIGNAL CIRCUIT. 1) Reconnect mass air flow sensor harness connector. 2) Start engine and warm it up sufficiently. 3) Read mass air flow sensor signal in DATA MONITOR mode with CONSULT. Voltage: 1.0 - 1.3V (At idle). OR 1) Disconnect ECM harness connector. 2) Check harness continuity between mass air flow sensor terminal a and ECM terminal 16. Continuity should exist.
NG
same as step 3
OK
5
CHECK COMPONENT (Mass air flow sensor). Refer to Electrical Components Inspection.
NG
Replace mass air flow sensor.
OK
6
Check ECM pin terminals for damage or poor connection of ECM harness connector.
See also
EF & EC-4039