Alternative Diagnosis

The J 42958 Cruise Control Tester may be used if desired. Refer to Service Bulletin 83-90-08A.

Did you perform the Cruise Control Diagnostic System Check?

Go to Step 2

Go to Cruise Control System Check

1. Turn OFF the ignition.
2. Disconnect the cruise control module.
3. Turn ON the ignition, with the engine OFF.
4. Probe the ignition positive voltage circuit of the cruise control module with a test lamp that is connected to a good ground.

Does the test lamp illuminate?

Go to Step 3

Go to Step 32

Probe the ignition positive voltage circuit of the cruise control module with a test lamp that is connected to the ground circuit of the cruise control module.

Does the test lamp illuminate?

Go to Step 4

Go to Step 33

1. Turn ON the ignition, with the engine OFF.
2. Turn OFF the cruise control.
3. Probe the on/off, the set/coast, and the resume/accelerate circuits with a test lamp that is connected to a good ground.

Does the test lamp illuminate on any of the circuits?

Go to Step 14

Go to Step 5

1. Turn ON the ignition, with the engine OFF.
2. Turn ON the cruise control.
3. Probe the on/off circuit with a test lamp that is connected to a good ground.

Does the test lamp illuminate?

Go to Step 6

Go to Step 15

1. Probe the set/coast circuit with a test lamp that is connected to a good ground.
2. Press and hold the SET/COAST switch.

Does the test lamp illuminate?

Go to Step 7

Go to Step 17

1. Probe the resume/accelerate circuit with a test lamp that is connected to a good ground.
2. Press and hold the RESUME/ACCEL switch.

Does the test lamp illuminate?

Go to Step 8

Go to Step 18

Probe the clutch pedal position switch circuit with a test lamp that is connected to a good ground.

Does the test lamp illuminate?

Go to Step 9

Go to Step 19

Depress the brake pedal while monitoring the test lamp.

Does the test lamp illuminate?

Go to Step 20

Go to Step 10

Probe the tcc/stop lamp switch circuit with a test lamp that is connected to a good ground.

Does the test lamp illuminate?

Go to Step 21

Go to Step 11

Depress the brake pedal while monitoring the test lamp.

Does the test lamp illuminate?

Go to Step 12

Go to Step 22

Probe the cruise engaged output circuit with a test lamp that is connected to a good ground.

Does the test lamp illuminate?

Go to Step 13

Go to Step 23

1. Raise and suitably support the vehicle.
2. Probe the VSS signal circuit with a DMM that is connected to a good ground.
3. Set the DMM to the AC scale.
4. Rotate one of the drive wheels.
5. Observe the DMM.

Does the voltage displayed on the scan tool vary?

Go to Step 31

Go to Step 24

Test the circuit that illuminated the test lamp for a short to voltage. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 39

Go to Step 30

Test the on/off circuit for an open or a high resistance. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 39

Go to Step 16

Test the ignition positive voltage circuit for an open or high resistance between the cruise control module and the cruise control switch. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 39

Go to Step 30

Test the set/coast circuit for an open or a high resistance. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 39

Go to Step 30

Test the resume/accelerate circuit for an open or a high resistance. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 39

Go to Step 30

Test the clutch pedal position switch circuit for an open or a high resistance. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 39

Go to Step 25

Test the clutch pedal position switch circuit for a short to voltage. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 39

Go to Step 25

Test the tcc/stop lamp switch circuit for a short to voltage. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 39

Go to Step 26

Test the tcc/stop lamp switch circuit for an open or a high resistance. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 39

Go to Step 26

Test the cruise engaged output circuit for an open, a high resistance, or a short to voltage. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 39

Go to Step 29

Test the speed sensor circuit for an open or a high resistance. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 39

Go to Step 29

Inspect the clutch pedal position [cruise release] switch for proper adjustment.

Did you find and correct the condition?

Go to Step 39

Go to Step 27

Inspect the tcc/stop lamp switch for proper adjustment.

Did you find and correct the condition?

Go to Step 39

Go to Step 28

Inspect for poor connections at the harness connector of the clutch pedal position switch. Refer to Circuit Testing and Connector Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 39

Go to Step 34

Inspect for poor connections at the harness connector of the tcc/stop lamp switch. Refer to Circuit Testing and Connector Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 39

Go to Step 35

Inspect for poor connections at the harness connector of the PCM. Refer to Circuit Testing and Connector Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 39

Go to Step 36

Inspect for poor connections at the harness connector of the cruise control switch. Refer to Circuit Testing and Connector Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 39

Go to Step 37

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

Did you find and correct the condition?

Go to Step 39

Go to Step 38

Repair the ignition positive voltage circuit of the cruise control module. Refer to Wiring Repairs in Wiring Systems.

Did you complete the repair?

Go to Step 39

--

Repair the ground circuit of the cruise control module. Refer to Wiring Repairs in Wiring Systems.

Did you complete the repair?

Go to Step 39

--

Replace the clutch pedal position switch. Refer to Clutch Pedal Engine Start Switch Replacement .

Did you complete the replacement?

Go to Step 39

--

Replace the tcc/stop lamp switch. Refer to Stop Lamp Switch Replacement .

Did you complete the replacement?

Go to Step 39

--

Replace the PCM. Refer to Powertrain Control Module Replacement/Programming or VCM Replacement/Programming in Engine Controls.

Did you complete the replacement?

Go to Step 39

--

Replace the cruise control switch. Refer to Multifunction, Turn Signal, and Hazard Switch Replacement - On Vehicle .

Did you complete the replacement?

Go to Step 39

--

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

Did you complete the replacement?

Go to Step 39

--

Operate the vehicle within the conditions for cruise control operation.

Does the cruise control system operate correctly?

System OK

Go to Step 2