2003 LEXUS LS430 c1751

For details of each code, go to Fig. 16
DTC C1715, DTC C1716, DTC C1717,
DTC C1791, DTC C1792, DTC C1793
RIGHT FRONT ACCELERATION SENSOR CIRCUIT
DTC C1725, DTC C1726, DTC C1727,
DTC C1728
RIGHT FRONT ABSORBER CONTROL ACTUATOR
CIRCUIT
DTC C1735EXHAUST SOLENOID VALVE CIRCUIT
DTC C1737, DTC C1738, DTC C1739,
DTC C1740
RIGHT FRONT HEIGHT CONTROL SOLENOID
VALVE CIRCUIT
DTC C1741AIR SUS RELAY CIRCUIT
DTC C1742HEIGHT CONTROL COMPRESSOR CIRCUIT
DTC C1751, DTC C1752CONTINUOUS ELECTRIC CURRENT TO HEIGHT
CONTROL COMPRESSOR
DTC C1761ECU MALFUNCTION
DTC C1774POWER SOURCE CIRCUIT
DTC C1776SPEED SENSOR CIRCUIT
DTC C1777STEERING ANGLE SENSOR CIRCUIT
DTC C1786HEIGHT CONTROL SWITCH CIRCUIT (TEST
DIAGNOSIS)
DTC C1787ABSORBER CONTROL SWITCH CIRCUIT (TEST
DIAGNOSIS)

Fig. 17: Diagnostic Trouble Code Information Chart (2 Of 2)
Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
*1: For codes in the "Indicator Light" column with a "circ" mark, the absorber control indicator lamp blinks at 1
second intervals.
*2: For codes in the "Indicator Light" column with a " (xcirc)" mark, when trouble occurs, "HEIGHT HI" is
displayed on the multi-information display. Also, the master warning light is lit on the combination meter and
an alarm sounds.
*3: Since the relief pressure of the compressed air is 980 kPa (10 kgf/cm
2 , 142 psi), if vehicle height control is
attempted on a steeply sloping road, when the vehicle is overloaded, or when the vehicle height is jacked up
with the engine running, code "C1751" may be output and vehicle height control may be suspended. (This is not
abnormal.) In this case, however, when detecting the first error, approximately 10 minutes after the ignition
switch was turned to the ON position, vehicle height control is resumed. When the following errors are
detected, it takes 70 minutes until the control is resumed.
*4: If vehicle height control is operated while the wheels are removed or the vehicle is jacked up, code "C1752"
may be output, but this is not abnormal. When code "C1752" is output, vehicle height control is not carried out.
However, control is resumed if the ignition switch is turned off, then to the ON position again.
CIRCUIT DESCRIPTION
The height control sensor sub-assy controls the resistance value by following changes in vehicle height. The
suspension control ECU detects the change in vehicle height from the transformed voltage. The suspension
control ECU outputs a constant voltage of 5 V to the SHB terminal of the height control sensor sub-assy.
In the height control sensor, the voltage is changed due to resistance. The changed voltage is output from the

10.INSPECT FOR CLOGGED AIR TUBE
a. Check the air tube visually for a clog or damage (see ON
-VEHICLE INSPECTION ).
OK:
Air tube is not clogged or damaged.
NG: REPAIR OR REPLACE AIR TUBE
OK: REPLACE SUSPENSION CONTROL ECU (SEE REPLACEMENT
)
CIRCUIT DESCRIPTION
The signal from the suspension control ECU operates the AIR SUS relay and the height control compressor
motor starts.
The height control compressor motor operates until the targeted vehicle height is reached. Then the height
control sensor sub-assy sends the signal to the suspension control ECU, and stops the height control compressor
motor.
Fig. 104: DTC C1751 And DTC C1752 Detecting Condition And Trouble Area

Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
INSPECTION PROCEDURE
1.CHECK HEIGHT CONTROL COMPRESSOR CIRCUIT (SEE DTC C1742 HEIGHT
CONTROL COMPRESSOR CIRCUIT )
2.CHECK AIR LEAKAGE (SEE ON
-VEHICLE INSPECTION )
OK:
No leaks

ENGINE IMMOBILIZER DIAGNOSTIC TROUBLE CODE (DTC) IDENTIFICATION (W/SMART
KEY)
ENGINE IMMOBILIZER DIAGNOSTIC TROUBLE CODES (DTC) IDENTIFICATION (W/O
SMART KEY)
C1714, DTC C1714 CIRCUIT
DTC C1715, DTC C1716, DTC C1717, DTC
C1791, DTC C1792, DTC C1793
RIGHT FRONT ACCELERATION SENSOR CIRCUIT
DTC C1725, DTC C1726, DTC C1727, DTC
C1728
RIGHT FRONT ABSORBER CONTROL ACTUATOR
CIRCUIT
DTC C1735 EXHAUST SOLENOID VALVE CIRCUIT
DTC C1737, DTC C1738, DTC C1739, DTC
C1740
RIGHT FRONT HEIGHT CONTROL SOLENOID
VALVE CIRCUIT
DTC C1741 AIR SUS RELAY CIRCUIT
DTC C1742 HEIGHT CONTROL COMPRESSOR CIRCUIT
DTC C1751, DTC C1752 CONTINUOUS ELECTRIC CURRENT TO HEIGHT
CONTROL COMPRESSOR
DTC C1761 ECU MALFUNCTION
DTC C1774 POWER SOURCE CIRCUIT
DTC C1776 SPEED SENSOR CIRCUIT
DTC C1777 STEERING ANGLE SENSOR CIRCUIT
DTC C1786 HEIGHT CONTROL SWITCH CIRCUIT (TEST
DIAGNOSIS)
DTC C1787 ABSORBER CONTROL SWITCH CIRCUIT (TEST
DIAGNOSIS)
DTCDescription
DTC B2780 PUSH SWITCH/KEY UNLOCK WARNING
SWITCH MALFUNCTION
DTC B2793 TRANSPONDER CHIP MALFUNCTION
DTC B2794 UNMATCHED ENCRYPTION CODE
DTC B2795 UNMATCHED KEY CODE
DTC B2797 COMMUNICATION MALFUNCTION NO.1
DTC B2799 ENGINE IMMOBILIZER SYSTEM
MALFUNCTION
DTCDescription
DTC B2780 PUSH SWITCH/KEY UNLOCK WARNING
SWITCH MALFUNCTION
DTC B2793 TRANSPONDER CHIP MALFUNCTION