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 hybrid vehicle control ECU or AFS ECU is installed.

DTC No.	DTC Detection Condition	Trouble Area
C1789	When either condition is met: Vehicle identification information is not stored. Vehicle identification information that is different from the stored information has been received 3 times.	Suspension control ECU Hybrid vehicle control ECU AFS ECU

DTC No.

DTC Detection Condition

Trouble Area

C1789

When either condition is met:

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

Suspension control ECU
Hybrid vehicle control ECU
AFS ECU

CAUTION / NOTICE / HINT

Note

Before performing troubleshooting, inspect the connectors of related circuits.
If DTC C1782 is output at the same time, perform troubleshooting for DTC C1782 first Click here.
If the suspension control ECU is replaced with a new one, enter test mode and perform registration of vehicle identification information Click here.
Do not exchange the suspension control ECU with a normally functioning one from another vehicle to perform troubleshooting.

PROCEDURE

CHECK VEHICLE IDENTIFICATION INFORMATION STATUS

Check that vehicle identification information has been stored Click here.

Result
Result	Proceed to
Information stored	A
Information not stored	B

PERFORM VEHICLE IDENTIFICATION INFORMATION REGISTRATION Click here

CHECK PART NUMBER
1. Check that the part numbers of the installed hybrid vehicle control ECU and AFS ECU are correct.
  
  Note
  
  When removing the hybrid vehicle control ECU and/or AFS ECU to check the part number, or when replacing the hybrid vehicle control ECU and/or AFS ECU, be sure to follow the appropriate procedures and precautions.
  Tech Tips
  - Refer to the hybrid vehicle control ECU installation procedure Click here.
  - Refer to the AFS ECU installation procedure Click here.
  OK
  
  Hybrid vehicle control ECU and AFS ECU with correct part numbers are installed.
NG
REPLACE CORRESPONDING ECU

OK
CLEAR DTC
1. Clear the DTCs Click here.
NEXT

OK
Hybrid vehicle control ECU and AFS ECU with correct part numbers are installed.

CHECK FOR DTC

Check if DTC C1789 is output Click here.

OK
DTC C1789 is not output.

Tech Tips

If no parts are replaced and DTC C1789 is output, there may be an internal malfunction in the suspension control ECU. In this case, replace the suspension control ECU.

Result
Result	Proceed to
OK	A
NG (for LHD)	B
NG (for RHD)	C

USE SIMULATION METHOD TO CHECK Click here

REPLACE SUSPENSION CONTROL ECU Click here