GM Service Manual Online
For 1990-2009 cars only

Circuit Description

The engine control module (ECM) turns the CRUISE lamp ON whenever actual cruise operation is present. The ECM controls the lamp by grounding the control circuit with an internal solid state device called a driver.

Conditions for Running the DTC

    • The battery voltage is between 7.5-15 volts.
    • The engine speed is more than 40 RPM.
    • The cruise control is engaged.

Conditions for Setting the DTC

An open, a short to voltage, or a short to ground is monitored by the ECM.

Action Taken When the DTC Sets

The ECM will not illuminate the malfunction indicator lamp (MIL).

Conditions for Clearing the MIL/DTC

    • The diagnostic trouble code (DTC) clears after 40 consecutive warm up cycles in which no failures are reported by this diagnostic or any other non-emission related diagnostic.
    • The scan tool clears the MIL/DTC.

Test Description

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

  1. After cruise is engaged, the CRUISE indicator lamp should illuminate.

Step

Action

Yes

No

Schematic Reference: Cruise Control Schematics

1

Did you perform the Cruise Control Diagnostic System Check?

Go to Step 2

Go to Diagnostic System Check - Cruise Control

2

Does the cruise control operate properly?

Go to Step 3

Go to Cruise Control Inoperative/Malfunctioning

3

Observe the CRUISE Indicator in the instrument panel cluster (IPC).

Is the CRUISE indicator lamp illuminated?

Go to Step 5

Go to Step 4

4

  1. Connect a scan tool.
  2. Command the CRUISE Indicator lamp ON from the Dash Lamps data list.

Did the CRUISE Indicator lamp in the IPC illuminate?

Go to Testing for Intermittent Conditions and Poor Connections in Wiring Systems

Go to Step 6

5

Test the CRUISE indicator signal circuit for a short to ground. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 13

Go to Step 9

6

Test the CRUISE indicator signal circuit for a open, high resistance or short to voltage. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 13

Go to Step 7

7

Inspect the CRUISE Indicator lamp in the IPC.

Is the CRUISE Indicator lamp open?

Go to Step 10

Go to Step 8

8

Inspect for poor connections at the harness connector of the IPC. 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 13

Go to Step 11

9

Inspect for poor connections at the harness connector of the PCM. 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 13

Go to Step 12

10

Replace the CRUISE Indicator lamp in the IPC. Refer to Instrument Cluster Indicator Lamp Replacement in Instrument Panel, Gages and Console.

Go to Step 13

--

11

Replace the IPC. Refer to Instrument Cluster Replacement in Instrument Panel, Gages and Console.

Did you complete the replacement?

Go to Step 13

--

12

Important: 

   • The PCM must be reprogrammed after replacement. Refer to Engine Control Module Programming Procedure in Engine Controls
   • This vehicle is equipped with a theft deterrent system that interfaces with the ECM. Program the new ECM with the frequency code of the theft deterrent module that is currently on the vehicle.

Replace the ECM. Refer to Engine Control Module Replacement in Engine Controls.

Did you complete the replacement?

Go to Step 13

--

13

  1. Using the scan tool, clear the DTCs.
  2. Operate the vehicle within the Conditions for Running this DTC.
  3. Operate the vehicle with cruise engaged.

Does the scan tool indicate that the diagnostic Passed?

System OK

Go to Step 2