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For 1990-2009 cars only
Makes 🢒 Cadillac 🢒 1999 🢒 Eldorado 🢒 Suspension 🢒 Road Sensing Suspension (RSS) 🢒 No RSS Data Loss of Serial Communications or Power

Object Number: 258330 Size: SF

Circuit Description

The CVRSS control module communicates to the other electronic control modules on the vehicle via the CLASS 2 serial bus.

Conditions for Setting the DTC

The DTC is also set when the power to the CVRSS control module has been lost because of one or more of the following:

    • loss of battery feed (loose terminals and/or fuses)
    • loss of ignition feed (loose terminals and/or fuses)
    • loss of a good CVRSS system ground
    • malfunction of the internal CVRSS control module.

The DTC is also set when the CVRSS control module is powered and operational, but is unable to communicate with the IPC because of an open circuit condition, a short circuit to ground condition, or a short circuit to voltage condition on the CLASS 2 circuit.

The DTC turns HISTORY when the IPC can communicate with the CVRSS control module.

Action Taken When the DTC Sets
    • The SERVICE RIDE CONTROL message will be displayed.
    • The vehicle speed may be limited, or the STABILITY REDUCED message will be displayed.
    • DTC P1611, U1056 and/or U1255 can be stored.

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.

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

Important: DTCs P1611, U1056, and U1255 can also be a result of:

   • Electrical problems with the wiring harness.
   • Intermittent breaks in Class 2 communication caused by other controllers and/or wiring harness issues.

  1. This step checks for a blown ignition fuse.

    2.

  2. This step checks for blown battery fuse.

    3.

  3. This step checks for an open circuit condition in the ground circuit.

    4.

  4. This step checks for an open circuit condition in the battery circuit.

    5.

  5. This step checks for an open circuit condition in the ignition circuit.

    6.

  6. This step checks the CLASS 2 bus for a fault condition.

    7.

  7. This step checks for a short circuit to ground condition in the ignition circuit.

    8.

  8. This step checks for a short circuit to ground condition in the battery circuit.

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. Check the RSS 10 amp fuse B13 (HOT IN RUN AND OFF) for a blown (open) circuit condition. RSS fuse B13 is located in the rear compartment fuse block.

Is the fuse blown?

--

Go to Step 15

Go to Step 3

3

Check the RSS 10 amp fuse D5 (HOT AT ALL TIMES) for a blown (open) circuit condition. RSS fuse D5 is located in the rear compartment fuse block.

Is the fuse blown?

--

Go to Step 17

Go to Step 4

4

Check for an open circuit condition in CKT 1050.

Important: Ground connection G403 should be torqued to the specified value.

Is an open circuit condition present?

10 N·m

Go to Step 5

Go to Step 6

5

Repair the open circuit condition in CKT 1050.

Is the repair complete?

--

Go to Road Sensing Suspension Diagnostic System Check

--

6

  1. Install all of the fuses that were removed.
  2. Turn the ignition ON with the engine off.
  3. Backprobe pin B1 of CVRSS control module connector C2 and measure the voltage between pin B1 and ground.

Is the measurement greater than the specified value?

10 V

Go to Step 8

Go to Step 7

7

Repair the open circuit condition in CKT 840.

Is the repair complete?

--

Go to Road Sensing Suspension Diagnostic System Check

--

8

Measure the voltage between pin B12 of CVRSS control module connector C2 and ground.

Is the measurement greater than the specified value?

10 V

Go to Step 10

Go to Step 9

9

Repair the open circuit condition in CKT 147.

Is the repair complete?

--

Go to Road Sensing Suspension Diagnostic System Check

--

10

Important: There are two 1807 circuits.

Check CKT 1807 (at connector C1 terminal D4) for the following conditions:

    • an open circuit condition
    • a short circuit to ground condition
    • a short circuit to voltage condition

Is a problem in CKT 1807 present?

--

Go to Step 11

Go to Step 12

11

Repair CKT 1807.

Is the repair complete?

--

Go to Road Sensing Suspension Diagnostic System Check

--

12

Important: There are two 1807 circuits.

Check CKT 1807 (at connector C1 terminal D5) for the following conditions:

    • an open circuit condition
    • a short circuit to ground condition
    • a short circuit to voltage

Is a problem in CKT 1807 present?

--

Go to Step 13

Go to Step 14

13

Repair CKT 1870.

Is the repair complete?

--

Go to Road Sensing Suspension Diagnostic System Check

14

Is DTC P1611 set?

--

Go to DTC P1611 Loss of CVRTD Serial Data in Engine Controls

Go to Step 21

15

  1. Turn the ignition OFF.
  2. Disconnect CVRSS control module connector C2.
  3. Check for a short circuit condition (continuity) between pin B12 of CVRSS connector C2 (harness side) and ground.

Is a short circuit condition present?

--

Go to Step 16

Go to Step 19

16

Repair the short circuit condition in CKT 147.

Is the repair complete?

--

Go to Step 20

--

17

  1. Turn the ignition OFF.
  2. Check for a short circuit condition (continuity) between pin B1 of CVRSS control module connector C2 and ground.

Is a short circuit condition present?

--

Go to Step 18

Go to Step 19

18

Repair the short circuit condition in CKT 840.

Is the repair complete?

--

Go to Step 20

--

19

Check for an intermittent short circuit to ground condition in the affected circuit.

Refer to Intermittents and Poor Connections .

Is the check complete?

--

Go to Step 21

--

20

Replace the appropriate fuse.

Is the replacement complete?

--

Go to Road Sensing Suspension Diagnostic System Check

--

21

    Important: Check for intermittent connections on fuses.

  1. Check all the electrical connections of the affected circuits (i.e. CKTs 840, 147, 1050, and 1807) for proper seating and crimps.
  2. Install all of the connectors and components that were removed.
  3. Turn the ignition ON with the engine off.
  4. Clear the DTCs. Refer to Clearing DTCs .
  5. Check the RSS DTCs. Refer to Displaying Diagnostic Trouble Codes (DTC) .

Does the IPC display NO RSS DATA?

--

Go to Step 22

Go to Road Sensing Suspension Diagnostic System Check

22
  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 CVRSS 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

--