DTC C1752: Height Control Compressor Motor Circuit Malfunction [08/2015 - 08/2019]: Procedure

1. Turn the ignition switch off.
2. Remove the AIR SUS relay from the engine room relay block.

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

3. Measure the resistance according to the value(s) in the table below.

   Standard Resistance

   Tester Connection	Condition	Specified Condition
   3 - 5	When 12 V battery voltage is not applied to terminal 1 and 2	10 kΩ or higher
   	When 12 V battery voltage is applied to terminal 1 and 2	Below 1 Ω

Result: 

NG 

REPLACE SUSPENSION CONTROL RELAY 

Result: 

OK 

See step  2

Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

1. Remove the AIR SUS relay from the engine room relay block.
2. Measure the voltage according to the value(s) in the table below.

   Standard Voltage

   Tester Connection	Condition	Specified Condition
   Relay block AIR SUS relay terminal 5 - Body ground	Always	11 to 14 V

3. Disconnect the Q7 compressor connector.
4. Disconnect the O17 ECU connector.
5. Measure the resistance according to the value(s) in the table below.

   Standard Resistance

   Tester Connection	Condition	Specified Condition
   Relay block AIR SUS relay terminal 3 - Q7-1 (B)	Always	Below 1 Ω
   Relay block AIR SUS relay terminal 3 or Q7-1 (B) - Body ground	Always	10 kΩ or higher
   Q7-2 (E) - Body ground	Always	Below 1 Ω
   Q7-3 (RM+) - O17-19 (RM+)	Always	Below 1 Ω
   Q7-3 (RM+) or O17-19 (RM+) - Body ground	Always	10 kΩ or higher
   Q7-4 (RM-) - O17-17 (RM-)	Always	Below 1 Ω
   Q7-4 (RM-) or O17-17 (RM-) - Body ground	Always	10 kΩ or higher

Result: 

NG 

REPAIR OR REPLACE HARNESS OR CONNECTOR 

Result: 

OK 

See step  3

1. Apply 12 V battery voltage to the compressor motor and check the operation of the motor.

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

   OK

   Measurement Condition	Specified Value
   12 V battery positive (+) → Terminal 1 (B) 12 V battery negative (-) → Terminal 2 (E)	Motor operates

   NOTE:

   • Do not allow the motor to operate for approximately 90 seconds or more.
   • If the compressor is shorted, locked, or has a similar type of malfunction, a large amount of current will be flowing. Therefore, if the motor does not operate, immediately stop this inspection.

Result: 

OK 

REPLACE SUSPENSION CONTROL ECU 

(Refer to REMOVAL [08/2015 - ] )

Result: 

NG 

REPLACE NO. 1 HEIGHT CONTROL COMPRESSOR 

(Refer to REMOVAL [08/2015 - ] )