C1784

SUSPENSION CONTROL: AIR SUSPENSION SYSTEM: C1784: Steering Angle Sensor Communication Error
C1784 - Steering Angle Sensor Communication Error

DESCRIPTION

The steering angle sensor signal is sent to the suspension control ECU through the CAN communication system. When there is a communication malfunction, it will be detected by the diagnosis function.





WIRING DIAGRAM





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 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

(a) Clear the DTC Air Suspension System.

(b) Perform a road test.

(c) Check if DTC C1784 and U0126 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 C1231/31 is 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 STEERING ANGLE SENSOR (POWER SOURCE)

(a) Disconnect the L21 sensor connector.





(b) Measure the voltage and resistance according to the value(s) in the table below.

Standard voltage:





Standard resistance:





(c) Check that the steering angle sensor's connector is not deformed or corroded.

OK:

No deformation or corrosion.

HINT
If the steering angle sensor's connector is defective, replace the sensor.

NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR
OK -- Continue to next step.

4. CHECK STEERING ANGLE SENSOR (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) Check the values by referring to the table below.

Air Suspension





OK:

Steering wheel turning angle value changes.

NG -- REPLACE STEERING ANGLE SENSOR Removal

OK -- REPLACE SUSPENSION CONTROL ECU Removal