GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Chevrolet 🢒 2001 🢒 Prizm 🢒 Body and Accessories 🢒 Cruise Control 🢒 DTC 012

Circuit Description

The cruise control module applies voltage to the magnetic clutch when the cruise control system is engaged. The circuit between the cruise control module and the magnetic clutch in the actuator is interrupted by the stoplamp switch whenever the brake pedal is pressed.

Diagnostic Aids

Check for the following:

    • Stoplamp switch out of adjustment, or faulty.
    • Open in the cruise control magnetic clutch.
    • An open, short, or ground in the WHT/BLK, RED/GRN, RED/BLK, GRN/BLK, or RED/YEL wires.

An intermittent malfunction may be caused by a fault in the magnetic clutch electrical circuit. Inspect the wiring harness and components for any of the following conditions:

    • Backed out terminals
    • Improper mating of terminals
    • Broken electrical connectors locks
    • Improperly formed or damaged terminals
    • Faulty terminal to wire connections
    • Physical damage to the wiring harness
    • A broken wire inside the insulation
    • Corrosion of electrical connections, splices, or terminals

Repair any electrical circuit faults that were found. Refer to Wiring Repairs in Wiring Systems.

Test Description

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

  1. This step tests the resistance of the cruise control servo magnetic clutch circuit.

    2.

  2. This step tests the stoplamp switch.

    3.

  3. This step tests the cruise control actuator arm for free movement with the magnetic clutch de-energized.

    4.

  4. This step tests the cruise control actuator arm for a malfunction with the magnetic clutch energized.

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 connector which is located next to the instrument panel compartment on the RH side of the instrument panel.
  3. Measure the resistance between cavity 8 of the cruise control module connector and ground.

Is the resistance within the specified range?

35-45 ohms

Go to Step 3

Go to Step 4

3
  1. Disconnect the cruise control servo connector.
  2. Test the servo ground circuit for a high resistance or an open condition. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

--

Go to Step 14

Go to Step 7

4

  1. Disconnect the stoplamp switch connector.
  2. Measure the resistance between cavity 3 and 4 of the stoplamp switch.
  3. Observe the resistance reading while pressing and releasing the brake pedal.

Does the resistance read infinite ohms while the pedal is pressed, and 0 ohms when the pedal is released?

--

Go to Step 5

Go to Step 9

5

Test the magnetic clutch control circuit between the cruise control module and the cruise control servo for an open or ground condition. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

--

Go to Step 14

Go to Step 6

6
  1. Disconnect the cruise control servo connector.
  2. Measure the resistance between cavity 3 and cavity 4 of the cruise control servo connector.

Is the resistance within the specified range?

35-45 ohms

Go to Step 7

Go to Step 11

7

  1. Disconnect the cruise control cable from the actuator.
  2. Move the actuator arm back and forth.

Does the actuator arm move freely in both directions?

--

Go to Step 8

Go to Step 13

8

  1. Disconnect the cruise control servo connector.
  2. Connect a fused jumper wire from ground to terminal 4 of the cruise control servo.
  3. Connect a fused jumper wire from B+ to terminal 3 of the cruise control servo.
  4. Attempt to move the actuator arm.

Does the actuator arm move?

--

Go to Step 11

Go to Step 10

9

Adjust or replace the stoplamp switch. Refer to Stop Lamp Switch Adjustment or Stop Lamp Switch Replacement .

Is the adjustment or replacement complete?

--

Go to Step 14

--

10

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 14

Go to Step 12

11

Inspect for poor connections at the harness connector of the cruise control servo. 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 14

Go to Step 13

12

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

Did you complete the replacement?

--

Go to Step 14

--

13

Replace the cruise control servo. Refer to Cruise Control Servo Replacement .

Did you complete the replacement?

--

Go to Step 14

--

14
  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