DTC C1752: Height Control Compressor Motor Circuit Malfunction: Procedure

1. Turn the engine switch off.
2. Remove the suspension control relay from the engine room No. 1 relay block.
   Fig 1: Identifying Suspension Control Relay Circuit Diagram

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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 to terminal 1 and 2	10 kΩ or higher
   	When battery voltage is applied to terminal 1 and 2	Below 1 Ω

NG → REPLACE SUSPENSION CONTROL RELAY 

OK: Go to next step 

1. Remove the suspension control relay from the engine room No. 1 relay block.
   Fig 2: Checking Harness And Connector (ECU - Compressor, Compressor - Battery And Body Ground)

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2. Measure the voltage according to the value(s) in the table below.

   Standard voltage

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

3. Disconnect the A57 compressor connector.
   Fig 3: Identifying A57 Compressor And A39 ECU Connectors

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4. Disconnect the A39 ECU connector.
5. Measure the resistance according to the value(s) in the table below.

   Standard resistance

   Tester Connection	Condition	Specified Condition
   Relay block suspension control relay terminal 3 - A57-1 (B)	Always	Below 1 Ω
   Relay block suspension control relay terminal 3 or A57-1 (B) - Body ground	Always	10 kΩ or higher
   A57-2 (E) - Body ground	Always	Below 1 Ω
   A57-3 (RM+) - A39-17 (RM+)	Always	Below 1 Ω
   A57-3 (RM+) or A39-17 (RM+) - Body ground	Always	10 kΩ or higher
   A57-4 (RM-) - A39-18 (RM-)	Always	Below 1 Ω
   A57-4 (RM-) or A39-18 (RM-) - Body ground	Always	10 kΩ or higher

NG → REPAIR OR REPLACE HARNESS OR CONNECTOR 

OK: Go to next step 

1. Remove the height control compressor. Refer to REMOVAL .
2. Connect terminal 1 (B) to the battery positive (+) terminal, and terminal 2 (E) to the battery negative (-) terminal.
   Fig 4: Identifying Height Control Compressor (Compressor Motor)

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3. Check the operating of the compressor motor.

   OK

   Motor operates

   NOTE:

   • Do not operate the height control compressor for 60 seconds or more.
   • Since a short and a lock-up inside the height control compressor cause excessive current to flow, stop operation immediately when it does not rotate.

NG → See step   4 

OK → See step   5