C1783

SUSPENSION CONTROL: AIR SUSPENSION SYSTEM: C1783: Speed Signal Communication Error
C1783 - Speed Signal Communication Error

DESCRIPTION

The speed sensors monitor the speed of the wheels, and send appropriate speed signals to the suspension control ECU through the skid control ECU. If trouble occurs in either the front speed sensor or rear speed sensor, DTC C1783 is output.





INSPECTION PROCEDURE

NOTICE:
- Before performing troubleshooting, inspect the connectors of related circuits.
- Before replacing the suspension control ECU, perform all of the following again: 1) symptom simulation Electronic Circuit Inspection Procedure; 2) DTC inspection; and 3) the Techstream inspection (Data List or Active Test). If no malfunctions are found in other areas, replace the suspension control ECU.
- If the suspension control ECU or height control sensor is replaced, the vehicle height offset calibration must be performed Programming and Relearning.

PROCEDURE

1. CHECK DTC (AIR SUSPENSION SYSTEM)

(a) Clear the DTC Air Suspension System.

(b) Perform a road test.

(c) Check if DTC C1783 and U0122 are output Air Suspension System.

Result





B -- GO TO CAN COMMUNICATION SYSTEM (HOW TO PROCEED WITH TROUBLESHOOTING) How to Proceed With Troubleshooting
A -- Continue to next step.

2. CHECK DTC (BRAKE CONTROL SYSTEM)

(a) Check if DTC C1783 and a brake control system speed sensor malfunction DTC (C0200/31, C0205/32, C0210/33, C0215/35, C1236/36, C1238/38 or C1239/39) are output Reading and Clearing Diagnostic Trouble Codes.

Result





B -- GO TO BRAKE CONTROL SYSTEM (DIAGNOSTIC TROUBLE CODE CHART) Electronically Controlled Brake System
A -- Continue to next step.

3. CHECK VEHICLE SPEED SIGNAL (DATA LIST)

(a) Turn the power switch OFF.

(b) Connect the Techstream to the DLC3.

(c) Turn the power switch ON (IG) and the Techstream ON.

(d) Enter the following menus: Chassis / Air suspension / Data List.

(e) Using the Techstream, read the DATA LIST.

Air Suspension





OK:

Vehicle speed indicated on the Techstream screen indicates the actual speed.

NG -- GO TO BRAKE CONTROL SYSTEM (HOW TO PROCEED WITH TROUBLESHOOTING) How To Proceed With Troubleshooting

OK -- REPLACE SUSPENSION CONTROL ECU Removal