GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 GMC_Truck 🢒 2001 🢒 Yukon - 2WD 🢒 Driveline/Axle 🢒 Transfer Case - NVG 236/246-NP8 (Two Speed Automatic) 🢒 Diagnostic System Check - Real Time Damping

Test Description

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

  1. Lack of communication may be due to a partial malfunction of the class 2 serial data circuit or due to a total malfunction of the class 2 serial data circuit. The specified procedure will determine the particular condition.

  2. Check for the presence of DTCs.

  3. The presence of DTCs which begin with "U" indicate some other module is not communicating. The specified procedure will compile all the available information before tests are performed.

    4.

  4. Check for the presence of DTCs.

Step

Action

Yes

No

1

Install a scan tool.

Does the scan tool power up?

Go to Step 2

Go to Scan Tool Does Not Power Up in Data Link Communications

2

  1. Turn ON the ignition, with the engine OFF.
  2. Attempt to establish communication with the Suspension (RTD) Control module, Instrument Cluster (IPC) and the Powertrain Control Module (PCM).

Does the scan tool communicate with each of the Modules?

Go to Step 3

Go to Scan Tool Does Not Communicate with Class 2 Device in Data Link Communications

3

Select the display DTCs function on the scan tool

Does the scan tool display any DTCs which begin with a "U"?

Go to Scan Tool Does Not Communicate with Class 2 Device in Data Link Communications

Go to Step 4

4

Select the Powertrain Control module display DTCs function on the scan tool.

Does the scan tool display any DTCs for VSS, TP Sensor or System Voltage?

Go to Diagnostic Trouble Code (DTC) List in Engine Controls

Go to Step 5

5

Select the Suspension Control module display DTCs function on the scan tool.

Does the scan tool display any DTCs?

Go to Step 6

Go to Symptoms - Real Time Damping

6
  1. Start the engine.
  2. Use the scan tool in order to clear the DTCs.

    3. Important: Do not turn the ignition OFF after clearing the DTCs.

  3. With the scan tool, command all the dampers ON and OFF 5 times or for 1 minute.
  4. Road test vehicle.
  5. Select the the Suspension Control module display DTCs function on the scan tool.

Does the scan tool display any DTCs?

Go to Step 7

System OK

7

Does the scan tool display DTC C0550 or C0551?

Go to Diagnostic Trouble Code (DTC) List

Go to Step 8

8

Does the scan tool display DTC C0870?

Go to DTC C0870

Go to Step 9

9

Does the scan tool display all of the following DTCs C0575, C0580, C0585 and C0590?

Go to DTC C0690

Go to Step 10

10

Does the scan tool display any of the following DTCs C0575, C0580, C0585 or C0590?

Go to Step 11

Go to Diagnostic Trouble Code (DTC) List

11
  1. Visual inspect the electrical connections at the suspect shock.
  2. Disconnect the shock electrical connector of the suspect shock and inspect the connector.
  3. Re-connect the connector.

    4. Important: Do not turn the ignition OFF after clearing the DTCs.

  4. Use the scan tool in order to clear the DTCs.
  5. With the scan tool, command all the dampers ON and OFF 5 times or for 1 minute.
  6. Select the the Suspension Control module display DTCs function on the scan tool.

Does the DTC reset?

Go to Diagnostic Trouble Code (DTC) List

Go to Symptoms - Real Time Damping