AIR SUSPENSION SYSTEM, Diagnostic DTC:C1789

DTC Code	DTC Name
C1789	Vehicle Identification Malfunction

DESCRIPTION

This DTC is stored when the suspension control ECU is initialized, and is cleared when the vehicle identification information received through CAN communication is correctly stored in the EEPROM.
DTC C1789 is stored as the vehicle specification and data do not match when an incorrect ECM is installed.

DTC No.	DTC Detection Condition	Trouble Area
C1789	When one of the following conditions is met: Vehicle identification information not registered. Vehicle identification information different from the stored information has been received 3 times.	Vehicle identification information not registered ECM Suspension control ECU

DTC No.

DTC Detection Condition

Trouble Area

C1789

When one of the following conditions is met:

Vehicle identification information not registered.
Vehicle identification information different from the stored information has been received 3 times.

INSPECTION PROCEDURE

Note

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 Click here.
Before replacing the suspension control ECU, perform all of the following again: 1) symptom simulation Click here; 2) DTC inspection Click here; and 3) Intelligent tester inspection (Data List or Active Test) Click here. 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 Click here and Click here

PROCEDURE

CHECK DTC (C1781)

Check for DTC C1781 Click here

Result

Condition	Proceed to
DTC C1781 is not output	A
DTC C1781 is output	B

REPLACE SUSPENSION CONTROL ECU Click here

REGISTRATION OF VEHICLE IDENTIFICATION INFORMATION
1. Perform registration of vehicle identification information Click here
NEXT

CHECK DTC (C1789)

Check for DTC C1789 Click here

Result

Condition	Proceed to
DTC C1789 is not output	A
DTC C1789 is output	B

CHECK CAN COMMUNICATION SYSTEM Click here

END

CHECK CAN COMMUNICATION SYSTEM

Check the CAN communication system for any malfunctions Click here.

Result

Condition	Proceed to
CAN communication system is normal	A
CAN communication system is malfunctioning	B

GO TO CAN COMMUNICATION SYSTEM Click here

CHECK ECM

Check if the part number of the installed ECM is correct.

OK
An ECM with the correct part number is installed.

Result

REPLACE ECM (2GR-FE) Click here

REPLACE ECM (1AR-FE) Click here

REPLACE SUSPENSION CONTROL ECU Click here