GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Cadillac 🢒 1999 🢒 Eldorado 🢒 Suspension 🢒 Road Sensing Suspension (RSS) 🢒 DTC C1788 Damper Control Relay Short to Bat

Object Number: 258353 Size: LF

Circuit Description

The high-side (battery) voltage for the CVRSS damper actuators is supplied to the CVRSS control module through the CVRSS Damper Control Relay (RTD BODY) circuit. The Damper Control Relay circuit is controlled by the CVRSS module. The CVRSS control module monitors the relay drive circuit and each damper actuator high-side and low-side drive circuits for fault conditions.

Conditions for Setting the DTC

The DTC is set when the CVRSS control module measures a feedback voltage greater than a preset threshold during a damper relay ON state.

The DTC turns HISTORY when the CVRSS control module no longer senses a high feedback voltage during a damper relay ON state.

Action Taken When the DTC Sets
    • ALL the damper actuators will be disabled by commanding 0 % PWM duty cycle. The vehicle ride will be soft.
    • The vehicle speed will be limited.
    • 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 for an internal open or short circuit condition in the coil of the relay.

    2.

  2. This step checks for a short circuit to voltage condition on CKT 1112.

    3.

  3. This step checks for intermittents.

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

  1. Turn the ignition OFF.
  2. Remove the RTD BODY relay.
  3. Measure the resistance between pin B7 and pin C5 of the RTD BODY relay (device side).

Is the measurement within the specified values?

50-125 ohms

Go to Step 3

Go to Step 8

3

  1. Disconnect CVRSS control module connector C1.
  2. Turn the ignition ON with the engine off.
  3. Measure the voltage between terminal C13 and ground.

Is the measurement greater than the specified value?

10 V

Go to Step 7

Go to Step 4

4

Check for intermittent short circuit to voltage conditions in CKT 1112. Refer to Intermittents and Poor Connections .

Is an intermittent short circuit to voltage condition present?

--

Go to Step 5

Go to Step 6

5

Repair the short circuit to voltage condition in CKT 1112.

Is the repair complete?

--

Go to Road Sensing Suspension Diagnostic System Check

--

6
  1. Install all of the connectors and components that were removed.
  2. Turn the ignition ON with the engine off.
  3. Clear the CVRSS DTCs. Refer to Clearing DTCs .
  4. Check the CVRSS DTCs. Refer to Displaying Diagnostic Trouble Codes (DTC) .

Is DTC C1788 set?

--

Go to Step 9

--

7
  1. Repair the short circuit to voltage condition in CKT 1112.
  2. Install all of the connectors and components that were removed.

Is the repair complete?

--

Go to Road Sensing Suspension Diagnostic System Check

--

8

Replace the RTD BODY relay.

Is the replacement complete?

--

Go to Road Sensing Suspension Diagnostic System Check

--

9
  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

--