MPI <4G63>
ï
Troubleshooting
13D-63
INSPECTION PROCEDURE 30
Power steering fluid pressure switch system
Probable cause
The presence or absence of power steering load is input to the engine-A/T-ECU.
The engine-A/T-ECU controls the idle speed control (ISC) servo based on this input.
D
Malfunction of the power steering fluid pressure switch
D
Improper
connector
contact,
open
circuit
or
short-circuited harness wire
D
Malfunction of the engine-A/T-ECU
Check the power steering fluid pressure switch.
(Refer to GROUP 37A
ï
On-vehicle Service.)
NG
Replace
OK
Measure at the power steering fluid pressure switch connector
B-115.
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
connector:
C-124
NG
Repair
OK
Check the trouble symptom.
NG
Check harness wire be-
tween
engine-A/T-ECU
and power steering fluid
pressure switch connec-
tor.
NG
Repair
OK
Replace the engine-A/T-ECU.
OK
Check
the
following
connector:
B-115
NG
Repair
OK
Check the trouble symptom.
NG
Replace the engine-A/T-ECU.
INSPECTION PROCEDURE 31
A/C switch and A/C relay system
Probable cause
When an A/C ON signal is input to the engine-A/T-ECU, the engine-A/T-ECU carries
out control of the idle speed control (ISC) servo, and also operates the A/C compressor
magnetic clutch.
D
Malfunction of the A/C control system
D
Malfunction of the A/C switch
D
Improper
connector
contact,
open
circuit
or
short-circuited harness wire
D
Malfunction of the engine-A/T-ECU
Check the A/C compressor relay.
(Refer to GROUP 55
ï
On-vehicle Service.)
NG
Replace
OK
Measure at the engine-A/T-ECU connectors C-122, C-126.
D
Disconnect the connectors, and measure at the harness side.
D
Voltage between 20 and earth, and 83 and earth
(Ignition switch: ON, A/C switch: ON)
OK:
System voltage
D
Short circuit between 20 and earth
OK:
A/C compressor clutch turns on.
NG
Check the A/C system. (Refer to GROUP 55
ï
On-vehicle Service.)
OK
Check
the
following
connectors:
C-122,
C-126
NG
Replace
OK
Check the trouble symptom.
NG
Replace the engine-A/T-ECU.
Summary of Contents for Lancer 2005
Page 5: ...NOTES ...