C1783

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

DTC 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) intelligent tester or 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 Testing and Inspection.

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)
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)
A -- Continue to next step.
3. CHECK VEHICLE SPEED SIGNAL (DATA LIST)
(a) Turn the power switch OFF.
(b) Connect the intelligent tester or Techstream to the DLC3.
(c) Turn the power switch ON (IG) and the tester ON.
(d) Enter the following menus:
(1) Intelligent tester - Select: DIAGNOSIS / OBD/MOBD / CHASSIS / AIR SUSPENSION / DATA LIST.
(2) Techstream - Select: Chassis / Air suspension / Data List.
(e) Using the intelligent tester or Techstream, read the DATA LIST.
(1) Intelligent tester

AIR SUSPENSION





(2) Techstream

Air suspension





OK:
Vehicle speed indicated on the tester indicates the actual speed.
NG -- GO TO BRAKE CONTROL SYSTEM (HOW TO PROCEED WITH TROUBLESHOOTING)
OK -- REPLACE SUSPENSION CONTROL ECU