Diagnostic Aids
Important: Perform the following in order to avoid misdiagnosis.
• Inspect for proper operation of brake lamps and clutch switch, if equipped. • EMI on the speed sensor signal circuit may cause erratic cruise control operation.
Conditions for Enabling Cruise Control
The vehicle speed is greater than 40 km/h (25 mph).
Step | Action | Yes | No |
|---|---|---|---|
Schematic Reference : Cruise Control Schematics | |||
1 | Did you perform A Diagnostic System Check - Cruise Control? | Go to Step 2 | |
2 |
Did the scan tool parameter change state? | Go to Step 3 | Go to Step 7 |
3 |
Did the cruise control set/coast parameter change state? | Go to Step 4 | Go to Step 11 |
4 |
Did the cruise control resume/accelerate parameter change state? | Go to Step 5 | Go to Step 12 |
5 |
Did the stop lamp switch parameter change state? | Go to Step 6 | Go to Step 8 |
6 |
Did the cruise release switch parameter change state? | Go to Step 7 | Go to Step 9 |
7 |
Did the test lamp illuminate? | Go to Step 10 | Go to Step 17 |
8 |
Did the test lamp illuminate? | Go to Step 13 | Go to Step 18 |
9 |
Did the test lamp illuminate? | Go to Step 15 | Go to Step 19 |
10 | Test the cruise control ON switch signal circuit for a open, high resistance, short to ground or short to voltage. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition? | Go to Step 28 | Go to Step 22 |
11 | Test the cruise control Set/Coast signal circuit for a open, high resistance, short to ground or short to voltage. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition? | Go to Step 28 | Go to Step 22 |
12 | Test the cruise control Resume/Accelerate signal circuit for a open, high resistance, short to ground or short to voltage. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition? | Go to Step 28 | Go to Step 22 |
13 | Test the stop lamp switch signal circuit for a open, high resistance, short to ground or short to voltage. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition? | Go to Step 28 | Go to Step 14 |
14 | Check the stop lamp switch for proper adjustment. Did you find and correct the condition? | Go to Step 28 | Go to Step 20 |
15 | Test the TCC/Brake switch signal circuit for a open, high resistance, short to ground or short to voltage. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition? | Go to Step 28 | Go to Step 16 |
16 | Check the TCC/Brake switch for proper adjustment. Did you find and correct the condition? | Go to Step 28 | Go to Step 21 |
17 | Repair the open, high resistance or short to ground in the multifunction turn signal lever ignition positive voltage circuit. Refer to Wiring Repairs in Wiring Systems. Did you complete the repair? | Go to Step 28 | -- |
18 | Repair the open, high resistance or short to ground in the stop lamp switch battery positive voltage circuit. Refer to Wiring Repairs in Wiring Systems. Did you complete the repair? | Go to Step 28 | -- |
19 | Repair the open, high resistance or short to ground in the TCC/Brake switch battery positive voltage circuit. Refer to Wiring Repairs in Wiring Systems. Did you complete the repair? | Go to Step 28 | -- |
20 | Inspect for poor connections at the harness connector of the stop lamp switch. 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 28 | Go to Step 24 |
21 | Inspect for poor connections at the harness connector of the TCC/Brake switch. 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 28 | Go to Step 25 |
22 | Inspect for poor connections at the harness connector of the multifunction turn signal lever. 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 28 | Go to Step 26 |
23 | 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 28 | Go to Step 27 |
24 | Replace the stoplamp switch. Refer to Stop Lamp Switch Replacement in Hydraulic Brakes. Did you complete the repair? | Go to Step 28 | -- |
25 | Replace the TCC/Brake switch. Refer to Stop Lamp Switch Replacement in Hydraulic Brakes. Did you complete the repair? | Go to Step 28 | -- |
26 | Replace the multifunction turn signal lever. Refer to Multifunction, Turn Signal, and Hazard Switch Replacement in Steering Wheel and Column. Did you complete the repair? | Go to Step 28 | -- |
27 |
Important: The PCM must be reprogrammed after replacement. Refer to Powertrain Control Module Programming in Engine Controls. Replace the PCM. Refer to Powertrain Control Module Replacement in Engine Controls. Did you complete the replacement? | Go to Step 28 | -- |
28 | Operate the vehicle with in the conditions for cruise control operation. Does the cruise control system operate properly? | System OK | Go to Step 2 |
