Conditions for Enabling Cruise Control
WARNING: This page is about a different car, the 2004 GMC Safari and 2004 Chevrolet Astro. However, it is still accessible from the selected car via links, so may be relevant.
The vehicle speed is greater than 40 km/h (25 mph).
Cruise Control Inoperative/Malfunctioning
| Step | Action | Value(s) | Yes | No |
|---|---|---|---|---|
| Schematic Reference: Cruise Control Schematics | ||||
| 1 | Did you perform A Diagnostic System Check - Cruise Control? | - | Go to Step 2 | Go to Diagnostic System Check - Cruise Control |
| 2 |
|
- | Go to Step 3 | Go to Step 29 |
| 3 | 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 30 |
| 4 |
|
- | Go to Step 14 | Go to Step 5 |
| 5 |
|
- | Go to Step 6 | Go to Step 15 |
| 6 |
|
- | Go to Step 7 | Go to Step 17 |
| 7 |
|
- | Go to Step 8 | Go to Step 18 |
| 8 | Probe the TCC/Brake signal 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 |
| 9 | Press the brake pedal while monitoring the test lamp. Does the test lamp go out? |
- | Go to Step 10 | Go to Step 20 |
| 10 | Probe the stop lamp signal 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 |
| 11 | Press the brake pedal while monitoring the test lamp. Does the test lamp illuminate? |
- | Go to Step 12 | Go to Step 22 |
| 12 | Probe the cruise control engaged signal circuit with a DMM that is connected to a good ground. Does the voltage measure near the specified value? |
B+ | Go to Step 13 | Go to Step 23 |
| 13 | Check the speedometer for proper operation. Does the speedometer operate properly? |
- | Go to Step 24 | Go to Symptoms - Instrument Panel, Gages and Console in Instrument Panel, Gages and Console |
| 14 | 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 35 | Go to Step 27 |
| 15 | Test the cruise control on switch signal circuit for a open, high resistance or short to ground. Refer to Circuit Testing
and Wiring Repairs
in Wiring Systems. Did you find and correct the condition? |
- | Go to Step 35 | Go to Step 16 |
| 16 | Test the ignition positive voltage circuit for a open, high resistance or short to ground 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 35 | Go to Step 27 |
| 17 | Test the cruise control set/coast switch signal 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 35 | Go to Step 27 |
| 18 | Test the cruise control resume/accelerate switch signal 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 35 | Go to Step 27 |
| 19 | Test the TCC/Brake signal 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 35 | Go to Step 25 |
| 20 | Test the TCC/Brake switch signal 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 35 | Go to Step 25 |
| 21 | Test the stop lamp switch signal 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 35 | Go to Step 25 |
| 22 | Test the stop lamp switch signal 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 35 | Go to Step 25 |
| 23 | Test the cruise control engaged signal circuit for an open, a high resistance, or a short to ground. Refer to Circuit Testing
and Wiring Repairs
in Wiring Systems. Did you find and correct the condition? |
- | Go to Step 35 | Go to Step 26 |
| 24 | Test the speed sensor circuit for a open, high resistance or short to ground between the cruise control module and the PCM. Refer to Circuit Testing
and Wiring Repairs
in Wiring Systems. Did you find and correct the condition? |
- | Go to Step 35 | Go to Step 26 |
| 25 | 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 35 | Go to Step 31 |
| 26 | 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 35 | Go to Step 34 |
| 27 | Inspect for poor connections at the harness connector of the cruise control 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 35 | Go to Step 32 |
| 28 | 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 35 | Go to Step 33 |
| 29 | 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 35 | - |
| 30 | Repair the ground circuit of the cruise control module. Refer to Wiring Repairs
in Wiring Systems. Did you complete the repair? |
- | Go to Step 35 | - |
| 31 | Replace the stop lamp switch. Refer to Stop Lamp Switch Replacement
in Lighting Systems. Did you complete the replacement? |
- | Go to Step 35 | - |
| 32 | Replace the multifunction turn signal lever. Refer to Multifunction, Turn Signal Switch Replacement
in Steering Wheel and Column. Did you complete the replacement? |
- | Go to Step 35 | - |
| 33 | Replace the cruise control module. Refer to Cruise Control Module Replacement . Did you complete the replacement? |
- | Go to Step 35 | - |
| 34 |
IMPORTANT:
The PCM must be reprogrammed after replacement. Replace the PCM. Refer to Powertrain Control Module (PCM) Replacement
in Engine Controls.Did you complete the replacement? |
- | Go to Step 35 | - |
| 35 | Operate the vehicle within the conditions for cruise control operation. Does the cruise control system operate correctly? |
- | System OK | Go to Step 2 |