C1742 PDF
C1742 PDF
C1742 PDF
CIRCUIT DESCRIPTION
The signal from the suspension control ECU turns on the AIR SUS relay. At that time, battery voltage is input
to the height control compressor motor through the AIR SUS relay. The height control compressor motor
starts.
DTC No. DTC Detecting Condition Trouble Area
S Height control compressor motor
With the AIR SUS relay activated, a lock signal of the height S Height control compressor circuit
C1742
control compressor motor is detected for 4 sec. or more. S Suspension control ECU
S Height control solenoid valve is stuck
WIRING DIAGRAM
AIRSUS ALT 1
BR
4 4A
2 1 2 1
B−L
W−B
Battery
IK EA
F45826
INSPECTION PROCEDURE
1 RECONFIRM DTC
OK
Height Control Compressor Motor: (a) Disconnect the height control compressor motor connec-
tor.
B (b) Connect terminal 1 (B) to the battery positive (+) terminal,
E
and terminal 2 (E) to the battery negative (−) terminal.
(c) Check the operating sound of the compressor motor.
OK:
Compressor motor operates.
NOTICE:
F45827 S Do not operate the height control compressor assy
for 60 seconds or more.
S Since a short and a lock−up inside the height control
compressor assy cause enormous current to flow,
stop operation immediately when it does not rotate.
HINT:
When a malfunction is found in the height control compressor
motor, replace the height control compressor assy.
NG REPLACE HEIGHT CONTROL COMPRESSOR
ASSY (SEE PAGE 25−9)
OK
Suspension Control ECU: (a) Connect the height control compressor motor connector.
(b) Disconnect the suspension control ECU A21 connector.
(c) Measure the resistance according to the value(s) in the
table below.
Standard:
Tester Connection Specified Condition
A21−17 (RM+) − A21−18 (RM−) 6.4 to 7.4 Ω
RM+
RM− NG REPAIR OR REPLACE HARNESS OR
A21 G25093 CONNECTOR
OK
Height Control Compressor Motor: (a) Measure the resistance according to the value(s) in the
table below.
Standard:
H11 E
Tester Connection Specified Condition
H11−2 (E) − Body ground Below 1 Ω
OK
Height Control Compressor Motor: (a) Disconnect the AIR SUS relay from the fusible link block.
(b) Measure the resistance according to the value(s) in the
table below.
B Standard:
Tester Connection Specified Condition
1 (B) − 2 (for AIR SUS relay) Below 1 Ω
1 (B) − Body ground 10 kΩ or higher
F45828
OK
OK
(d) Check the operation sound of the height control solenoid valve when the solenoid is turned on through
the ACTIVE TEST.
OK:
An operation sound is heard 1 second after the height control solenoid valve is turned on.
NG Go to step 8
OK
Go to step 9
Height Control Solenoid Valve Front RH: HEIGHT CONTROL SOLENOID VALVE FRONT RH:
(a) Disconnect the height control solenoid valve connector.
(b) Connect terminal 3 (SLFR) to the battery positive (+) ter-
minal, and terminal 2 (GND) to the battery negative (−) ter-
minal.
(c) Check the operating sound of the height control solenoid
valve.
OK:
SLFR GND
G25100 It should make an operating sound (click).
Result:
OK A
NG B
HINT:
When a malfunction is found in the front solenoid valve, replace
the height control valve sub−assy No.1.
Height Control Solenoid Valve Front LH: HEIGHT CONTROL SOLENOID VALVE FRONT LH:
(a) Disconnect the height control solenoid valve connector.
(b) Connect terminal 1 (SLFL) to the battery positive (+) ter-
minal, and terminal 2 (GND) to the battery negative (−) ter-
minal.
(c) Check the operating sound of the height control solenoid
valve.
GND OK:
SLFL
G25100 It should make an operating sound (click).
Result:
OK A
NG B
HINT:
When a malfunction is found in the front solenoid valve, replace
the height control valve sub−assy No.1.
Height Control Solenoid Valve Rear RH: HEIGHT CONTROL SOLENOID VALVE REAR RH:
(a) Disconnect the height control solenoid valve connector.
(b) Connect terminal 1 (SLRR) to the battery positive (+) ter-
minal, and terminal 2 (GND) to the battery negative (−) ter-
minal.
(c) Check the operating sound of the height control solenoid
valve.
OK:
GND SLRR
G25100 It should make an operating sound (click).
Result:
OK A
NG C
HINT:
When a malfunction is found in the rear solenoid valve, replace
the height control valve sub−assy No.2.
Height Control Solenoid Valve Rear LH: HEIGHT CONTROL SOLENOID VALVE REAR LH:
(a) Disconnect the height control solenoid valve connector.
(b) Connect terminal 3 (SLRL) to the battery positive (+) ter-
minal, and terminal 2 (GND) to the battery negative (−) ter-
minal.
(c) Check the operating sound of the height control solenoid
valve.
OK:
SLRL GND
G25100 It should make an operating sound (click).
Result:
OK A
NG C
HINT:
When a malfunction is found in the rear solenoid valve, replace
the height control valve sub−assy No.2.
B REPLACE HEIGHT CONTROL VALVE
SUB−ASSY NO.1 (SEE PAGE 25−17)
OK
(a) Check the air tube visually for a clog or damage (see page 25−4).
OK:
Air tube is not clogged or damaged.
NG REPAIR OR REPLACE AIR TUBE
OK