DTC C1752: Height Control Compressor Motor Circuit Malfunction (FROM 08/2009): Procedure

1. Turn the engine switch off.
2. Remove the AIR SUS relay from the engine room J/B.
   Fig 1: Identifying Suspension Control Relay Circuit Diagram

   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 battery voltage is not applied between terminals 1 and 2	10 kΩ or higher
   	When battery voltage is applied between terminals 1 and 2	Below 1 Ω

NG → REPLACE AIR SUS RELAY 

OK: Go to next step 

1. Disconnect the compressor motor connector.
2. Connect a positive (+) lead from the battery to terminal 1 (B) and a negative (-) lead to terminal 2 (E).
   Fig 2: Identifying Positive (+) Lead From The Battery To Terminal 1(B), And A Negative (-) Lead To Terminal 2 (E)

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
3. Check the operation of the compressor motor.

   OK

   Motor operates

   TEXT IN ILLUSTRATION
   
   

   *1	Component without harness connected (Compressor Motor)

   NOTE:

   • Do not operate the height control compressor for 60 seconds or more.
   • Stop applying voltage immediately if the compressor stops operating because a short will occur and the compressor motor will lock up, causing the flow of excessive current.

NG → See step   6 

OK: Go to next step 

1. Remove the AIR SUS relay from the engine room J/B.
   Fig 3: Identifying Engine Room J/B And Compressor Motor

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
2. Measure the voltage according to the value(s) in the table below.

   Standard voltage

   Tester Connection	Condition	Specified Condition
   J/B AIR SUS relay terminal 5 - Body ground	Always	11 to 14 V

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   *1

   Component without relay (Engine Room J/B)

   *2

   Front view of wire harness connector (to Compressor Motor)

3. Disconnect the P24 compressor connector.
4. Measure the resistance according to the value(s) in the table below.

   Standard resistance

   Tester Connection	Condition	Specified Condition
   J/B AIR SUS relay terminal 3 - P24-1 (B)	Always	Below 1 Ω
   P24-1 (B) - Body ground	Always	10 kΩ or higher
   P24-2 (E) - Body ground	Always	Below 1 Ω

NG → REPAIR OR REPLACE HARNESS OR CONNECTOR 

OK: Go to next step 

1. Disconnect the A55 ECU connector.
   Fig 4: Identifying A55 ECU Connector

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
2. Measure the resistance according to the value(s) in the table below.

   Standard resistance

   Tester Connection	Condition	Specified Condition
   A55-19 (RM+) - A55-17 (RM-)	Always	6.4 to 7.4 mΩ

   TEXT IN ILLUSTRATION
   
   

   *1	Rear view of wire harness connector (to Suspension Control ECU)

NG → REPAIR OR REPLACE HARNESS OR CONNECTOR 

OK → See step   5