Up to 08/2009

SUSPENSION CONTROL: AIR SUSPENSION SYSTEM: C1761: Continuous Electric Current to Height Control Compressor Motor
C1761 - Continuous Electric Current to Height Control Compressor Motor

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 sends the signal to the suspension control ECU, and stops the height control compressor motor.

INSPECTION PROCEDURE

NOTICE:
- Before performing troubleshooting, inspect the connectors of related circuits.
- If DTC C1782 (Power Source Voltage Malfunction) is output at the same time, perform troubleshooting for C1782 first C1782.
- Before replacing the suspension control ECU, perform all of the following again: 1) symptom simulation How To Proceed With Troubleshooting; 2) DTC inspection Reading and Clearing Diagnostic Trouble Codes; and 3) Techstream inspection (Data List or Active Test) Scan Tool Testing and Procedures. If no malfunctions are found in other areas, replace the suspension control ECU.
- If the suspension control ECU is replaced, the vehicle height offset calibration and registration of vehicle identification information must be performed Calibration and Registration)
PROCEDURE

1. CUSTOMER PROBLEM ANALYSIS

(a) Ask the customer about the vehicle and usage conditions when the DTC was stored.

HINT
DTC 1761 can be stored under unusual vehicle or usage conditions.

NEXT -- Continue to next step.

2. CHECK DTC

(a) Clear the DTC Reading and Clearing Diagnostic Trouble Codes.

(b) Start the engine and wait for 4 minutes or more.

(c) Select luggage mode.

(d) Select HI mode.

(e) Check the DTC Reading and Clearing Diagnostic Trouble Codes.

Result:

C -- GO TO DTC CHART

B -- END (C1761 WAS OUTPUT DUE TO UNUSUAL VEHICLE OR USAGE CONDITION)
A -- Continue to next step.

3. INSPECT AIR TUBE FOR AIR LEAK OR CLOG

(a) Inspect the air tube for air leaks or clogs Suspension Control System.

OK:

No air leaks or clogs are found in the air tube.

NG -- REPAIR OR REPLACE AIR TUBE
OK -- Continue to next step.

4. INSPECT HEIGHT CONTROL VALVE NO. 1

(a) Turn the engine switch off.

(b) Disconnect the height control valve No. 1 connector.

Text in Illustration

(d) Check the front RH valve.

(1) Connect a positive (+) lead from the battery to terminal 3 (RH+) and a negative (-) lead to terminal 2 (E).

(2) Check the operating sound of the height control valve No. 1.

OK:

It makes an operating sound (click).

(e) Check the front LH valve.

(1) Connect a positive (+) lead from the battery to terminal 1 (LH+) and a negative (-) lead to terminal 2 (E).

(2) Check the operating sound of the height control valve No. 1.

OK:

It makes an operating sound (click).

NG -- REPLACE HEIGHT CONTROL VALVE NO. 1
OK -- Continue to next step.

5. INSPECT HEIGHT CONTROL VALVE NO. 2

(a) Turn the engine switch off.

(b) Disconnect the rear height control valve No. 2 connector.

Text in Illustration

(d) Check the rear RH valve.

(1) Connect a positive (+) lead from the battery to terminal 3 (RH+) and a negative (-) lead to terminal 2 (E).

(2) Check the operating sound of the height control valve No. 2.

OK:

It makes an operating sound (click).

(e) Check the rear LH valve.

(1) Connect a positive (+) lead from the battery to terminal 1 (LH+) and a negative (-) lead to terminal 2 (E).

(2) Check the operating sound of the height control valve No. 2.

OK:

It makes an operating sound (click).

NG -- REPLACE HEIGHT CONTROL VALVE NO. 2
OK -- Continue to next step.

6. INSPECT HEIGHT CONTROL COMPRESSOR ASSEMBLY (EXHAUST VALVE)

(a) Turn the engine switch off.

(b) Disconnect the exhaust valve connector.

Text in Illustration

(d) Inspect if exhaust valve is stuck:

(1) Connect a positive (+) lead from the battery to terminal 2 (B) and a negative (-) lead to terminal 1 (L).

(2) Check the operating sound of the exhaust valve.

OK:

It makes an operating sound (click).

NG -- REPLACE HEIGHT CONTROL COMPRESSOR ASSEMBLY Removal
OK -- Continue to next step.

7. INSPECT PNEUMATIC W/TUBE TANK ASSEMBLY (LOW PRESSURE TANK VALVE)

(a) Turn the engine switch off.

(b) Disconnect the low pressure tank valve connector.

Text in Illustration

(d) Inspect if the low pressure tank valve is stuck :

(1) Connect a positive (+) lead from the battery to terminal 2 (B) and a negative (-) lead to terminal 1 (L).

(2) Check the operating sound of the low pressure tank valve.

OK:

It makes an operating sound (click).

NG -- REPLACE PNEUMATIC W/TUBE TANK ASSEMBLY
OK -- Continue to next step.

8. INSPECT HEIGHT CONTROL COMPRESSOR ASSEMBLY (COMPRESSOR MOTOR)

(a) Turn the engine switch off.

(b) Disconnect the compressor motor connector.

(c) Connect a positive (+) lead from the battery to terminal 1 (B) and a negative (-) lead to terminal 2 (E).

(d) Check the operating of the compressor motor.

OK:

Motor operates

Text in Illustration

NOTICE:
- 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 -- REPLACE HEIGHT CONTROL COMPRESSOR ASSEMBLY Removal
OK -- Continue to next step.

9. INSPECT AIR SUS RELAY

(a) Turn the engine switch off.

(b) Remove the AIR SUS relay from the engine room J/B.

NG -- REPLACE AIR SUS RELAY

OK -- REPLACE SUSPENSION CONTROL ECU