MPI <4G1> -
Troubleshooting
13A-61
INSPECTION PROCEDURE 27
Ignition switch-ST system
Probable cause
The ignition switch-ST inputs a HIGH signal to the engine-ECU while the engine is
cranking.
The engine-ECU controls fuel injection, etc. during starting based on this input.
D
Malfunction of ignition switch
D
Improper connector contact, open circuit or
short-circuited harness wire
D
Malfunction of the engine-ECU
Measure at the engine-ECU connector B-34.
D
Disconnect the connector, and measure at the harness side.
D
Voltage between 71 and earth (Ignition switch: START)
OK:
8V or more
NG
Check the following con-
nectors:
B-33, B-34
NG
Repair
OK
Check the trouble symptom.
NG
Check harness wire between
the engine-ECU and ignition
switch connector.
NG
Repair
OK
Check the ignition switch.
(Refer to GROUP 54 - Ignition Switch and Immobilizer system.)
OK
Check the following
connector:
B-34
NG
Repair
OK
Check the trouble symptom.
NG
Replace the engine-ECU.
INSPECTION PROCEDURE 28
Power steering fluid pressure switch system
Probable cause
The presence or absence of power steering load is input to the engine-ECU.
The engine-ECU controls the idle speed control (ISC) servo based on this input.
D
Malfunction of power steering fluid pressure switch
D
Improper connector contact, open circuit or
short-circuited harness wire
D
Malfunction of the engine-ECU
Check the power steering fluid pressure switch.
(Refer to GROUP 37A - On-vehicle Service.)
NG
Replace
OK
Measure at the power steering fluid pressure switch connector
A-78.
D
Disconnect the connector, and measure at the harness side.
D
Voltage between 1 and earth (Ignition switch: ON)
OK:
System voltage
NG
Check the following
connectors:
A-10, B-36
NG
Repair
OK
Check the trouble symptom.
NG
Check
harness
wire
between engine-ECU and
power steering fluid pres-
sure switch connector.
NG
Repair
OK
Replace the engine-ECU.
OK
Check the following
connector:
A-78
NG
Repair
OK
Check the trouble symptom.
NG
Replace the engine-ECU.