Diagnostic Aids
Important: Perform the following in order to avoid misdiagnosis.
• Inspect for proper operation of brake lamps. • Inspect throttle linkage for mechanical binding which could cause
the system to malfunction. • Inspect cruise control cable adjustment, should have minimum slack. • 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 | Value(s) | Yes | No |
|---|---|---|---|---|
SCHEMATIC REFERENCE: Cruise Control Schematics | ||||
1 | Did you perform A Diagnostic System Check- Cruise Control? | -- | Go to Step 2 | |
2 |
Does the test lamp illuminate? | -- | Go to Step 3 | Go to Step 19 |
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 35 |
4 |
Does the test lamp illuminate on any of the circuits? | -- | Go to Step 17 | Go to Step 5 |
5 |
Does the test lamp illuminate? | -- | Go to Step 6 | Go to Step 18 |
6 |
Does the test lamp illuminate? | -- | Go to Step 7 | Go to Step 21 |
7 |
Does the test lamp illuminate? | -- | Go to Step 8 | Go to Step 22 |
8 | Probe the stop lamp circuit with a test lamp that is connected to a good ground. Does the test lamp illuminate? | -- | Go to Step 24 | Go to Step 9 |
9 | Press the brake pedal while monitoring the test lamp. Does the test lamp illuminate? | -- | Go to Step 10 | Go to Step 23 |
10 | Probe the brake/clutch signal circuit with a test lamp that is connected to a good ground. Does the test lamp illuminate? | -- | Go to Step 14 | Go to Step 11 |
11 | Is the vehicle equipped with a manual transmission? | -- | Go to Step 12 | Go to Step 26 |
12 |
Did the test lamp illuminate? | -- | Go to Step 26 | Go to Step 13 |
13 |
Did the test lamp illuminate? | -- | Go to Step 27 | Go to Step 36 |
14 | Press the brake pedal while monitoring the test lamp. Does the test lamp illuminate? | -- | Go to Step 25 | Go to Step 15 |
15 | Probe the cruise engaged output circuit with a DMM that is connected to a good ground. Does the voltage measure near the specified value? | B+ | Go to Step 16 | Go to Step 28 |
16 | Check the speedometer for proper operation. Does the speedometer operate properly? | -- | Go to Step 29 | Go to Diagnostic System Check - Instrument Cluster in Instrument Panel, Gages and Console |
17 | 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 41 | Go to Step 33 |
18 | Test the on/off signal circuit for an open or a 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 41 | Go to Step 20 |
19 | Test the ignition positive voltage circuit of the cruise control module for a open circuit or high resistance and the cruise control switch signal circuits 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 41 | Go to Step 24 |
20 | Test the cruise control switch ignition positive voltage 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 41 | Go to Step 33 |
21 | Test the set/coast circuit for an open or a 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 41 | Go to Step 33 |
22 | 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 41 | Go to Step 33 |
23 | Test the brake cut out 1 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 41 | Go to Step 30 |
24 | Test the brake 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 41 | Go to Step 30 |
25 | Test the cruise release 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 41 | Go to Step 30 |
26 | Test the cruise release circuit for an open or a 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 41 | Go to Step 31 |
27 | Test the CPP switch ignition positive voltage 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 41 | Go to Step 30 |
28 | Test the cruise engaged output 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 41 | Go to Step 32 |
29 | Test the speed sensor circuit for an open or a high resistance between the cruise control module and PCM. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition? | -- | Go to Step 41 | Go to Step 34 |
30 | Inspect for poor connections at the harness connector of the stop lamp switch. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition? | -- | Go to Step 41 | Go to Step 37 |
31 | Inspect for poor connections at the harness connector of the CPP switch. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition? | -- | Go to Step 41 | Go to Step 37 |
32 | Inspect for poor connections at the harness connector of the VCM. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition? | -- | Go to Step 41 | Go to Step 40 |
33 | Inspect for poor connections at the harness connector of the cruise control switch. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition? | -- | Go to Step 41 | Go to Step 38 |
34 | Inspect for poor connections at the harness connector of the cruise control module. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition? | -- | Go to Step 41 | Go to Step 39 |
35 | Repair the ground circuit of the cruise control module. Refer to Wiring Repairs in Wiring Systems. Did you complete the repair? | -- | Go to Step 41 | -- |
36 | Repair the open ignition positive voltage of the stop lamp switch. Refer to Wiring Repairs in Wiring Systems. Did you complete the repair? | -- | Go to Step 41 | -- |
37 | Replace the appropriate switch. Refer to Clutch Pedal Engine Start Switch Replacement in Transmission/ Transaxle or Stop Lamp Switch Replacement in Hydralic Brakes. Did you complete the replacement? | -- | Go to Step 41 | -- |
38 | Replace the multifunction switch. Refer to Multifunction, Turn Signal, and Hazard Switch Replacement - On Vehicle in Steering Wheel and Column. Did you complete the replacement? | -- | Go to Step 41 | -- |
39 | Replace the cruise control module. Refer to Cruise Control Module Replacement . Did you complete the replacement? | -- | Go to Step 41 | -- |
40 | Replace the PCM/VCM. Refer to Powertrain Control Module Replacement/Programming in Engine Controls - 2.2L or VCM Replacement/Programming in Engine Controls - 4.3L. Did you complete the replacement? | -- | Go to Step 41 | -- |
41 | Operate the vehicle within the conditions for cruise control operation. Does the cruise control system operate correctly? | -- | System OK | Go to Step 2 |
