GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Cadillac 🢒 1999 🢒 Eldorado 🢒 Suspension 🢒 Road Sensing Suspension (RSS) 🢒 DTC C1743 Speed Signal Fault

Object Number: 258337 Size: SF

Circuit Description

The CVRSS control module receives a vehicle speed signal from the Powertrain Control Module (PCM) via a discrete line and also receives vehicle speed data via the Class 2 communication link. The CVRSS module compares the vehicle speed received over Class 2 to the vehicle speed obtained directly from the PCM.

Conditions for Setting the DTC

The DTC is set when the vehicle speed received over Class 2 is greater than 20 MPH while the vehicle speed obtained from the PCM is less than 3 MPH continuously for 10 seconds.

The DTC turns HISTORY when the CVRSS control module senses the vehicle speed signal from the PCM is greater than 5 MPH.

Action Taken When the DTC Sets
    • The CVRSS system will use only the Class 2 vehicle speed data. Otherwise, the CVRSS system will operate normally.
    • The SERVICE RIDE CONTROL message will be displayed.

Conditions for Clearing the MIL/DTC
    • Use the scan tool.
    • Use the On-Board diagnostic CLEAR RSS CODES feature.

Test Description

Important: 

   • Do not backprobe the sensors, actuators, or any sealed connectors.
   • When all the diagnostics and repairs are complete, clear the DTCs and verify the operation.

The number(s) below refer to the step number(s) on the diagnostic table.

  1. This step checks to see if the related PCM DTC is set.

    2.

  2. This step checks for an open circuit condition in CKT 817.

Step

Action

Value(s)

Yes

No

1

Was the CVRSS System Check performed?

--

Go to Step 2

Go to Road Sensing Suspension Diagnostic System Check

2

Is DTC P1642 set?

--

Go to DTC P1642 Vehicle Speed Output Circuit in Engine Controls

Go to Step 3

3
  1. Turn the ignition OFF.
  2. Disconnect connector C205.
  3. Disconnect CVRSS connector C1.
  4. Check for continuity between pin P of the C205 connector and pin C6 of CVRSS connector C1.

Was there continuity?

--

Go to Step 4

Go to Step 5

4

Check for an intermittent open circuit condition in CKT 817. Refer to Intermittents and Poor Connections .

Was an intermittent open circuit condition found?

--

Go to Step 5

Go to Step 6

5

Repair the intermittent open circuit condition in CKT 817.

Is the repair complete?

--

Go to Road Sensing Suspension Diagnostic System Check

--

6
  1. Install all of the connectors that were removed.
  2. Turn the ignition ON.
  3. Clear the DTCs. Refer to Clearing DTCs .
  4. Drive the vehicle over 20 MPH for more than 10 seconds.
  5. Check the DTCs. Refer to Displaying Diagnostic Trouble Codes (DTC) .

Is DTC C1743 set?

--

Go to Step 7

Go to Road Sensing Suspension Diagnostic System Check

7
  1. Turn the ignition OFF.
  2. Replace the CVRSS control module. Refer to Electronic Suspension Control Module Replacement .
  3. Install all of the connectors and components that were removed.
  4. Install the scan tool.
  5. Turn the ignition ON with the engine off.

    6. Important: The controller must be calibrated.

  6. Calibrate the CVRSS service controller using the scan tool. Refer to Electronic Suspension Control Module Calibration .

Is the CVRSS control module calibrated?

--

Go to Road Sensing Suspension Diagnostic System Check

--