GM Service Manual Online
For 1990-2009 cars only

Circuit Description

This DTC is used to monitor the voltage level available to the cruise control module at terminal 9 (BLK/YEL wire).

Diagnostic Aids

Check for the following:

    • Open or high resistance in the BLK/YEL wire.
    • Open, high resistance or low voltage in the power distribution to the ECU-IG fuse in junction block 2.
    • Open or high resistance in the WHT/BLK wire.
    • Open or high resistance in the ground distribution to splice pack 250/G203.
    • Vehicle charging system for poor performance.
    • Faulty cruise control module.

An intermittent may be caused by a poor connection, rubbed through wire insulation or a wire broken inside the insulation. Inspect the following harness connectors for backed out terminals, improper mating, broken lock, improperly formed or damaged terminals or for poor terminal-to-wire connection before replacing the suspect component:

    • Cruise control module connector
    • Junction block 2 C4
    • Splice pack 250
    • Ignition switch

Test Description

The numbers below refer to the step numbers on the diagnostic table.

  1. This step tests the condition of the power feed circuit to the module.

  2. This step tests for a faulty cruise control module.

Step

Action

Value(s)

Yes

No

Schematic Reference: Cruise Control Schematics

1

Did you perform the Diagnostic System Check - Cruise Control ?

--

Go to Step 2

Go to Diagnostic System Check - Cruise Control

2

  1. Turn OFF the ignition.
  2. Disconnect the cruise control module.
  3. Measure the voltage between cavity 9 and chassis ground.

Is the voltage within the specified value?

0-10 V

Go to Step 6

Go to Step 3

3

  1. Reconnect the cruise module connector.
  2. Test drive the vehicle at approximately 80 km/h (50 mph).
  3. Engage the cruise control and observe the performance for one minute.
  4. Stop the vehicle and test for DTCs.

Does this DTC reset?

--

Go to Step 4

Go to Step 5

4

Inspect for poor connections at the harness connector of the cruise control module. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems.

Did you find and correct the condition?

--

Go to Step 8

Go to Step 7

5

Repair the high resistance open condition in the BLK/YEL wire to the module in cavity 9. Refer to Wiring Repairs in Wiring System.

Is the repair complete?

--

Go to Step 8

--

6

Repair the short to voltage in the BLK/YEL wire to the module in cavity 9. Refer to Wiring Repairs in Wiring System.

Is the repair complete?

--

Go to Step 8

--

7

Replace the cruise control module. Refer to Cruise Control Module Replacement .

Did you complete the replacement?

--

Go to Step 8

--

8

  1. Turn OFF the ignition.
  2. Remove the STOP fuse.
  3. Remove the ECU-B fuse.
  4. Wait 30 seconds.
  5. Reinstall STOP and ECU-B fuses.
  6. Turn ON the ignition, with the engine OFF.
  7. Using the jumper, connect the DLC terminals Tc and E1.

Does the CRUISE indicator lamp flash the same trouble code?

--

Go to Step 2

System OK