Diagnostic Aids
Important: Perform the following in order to avoid misdiagnosis:
| • | Inspect for proper adjustment of the brake switches . |
| • | 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. |
Step | Action | Value(s) | Yes | No |
|---|---|---|---|---|
Schematic Reference: Cruise Control Schematics | ||||
1 | Did you perform the Cruise Control Diagnostic System Check? | -- | Go to Step 2 | |
2 |
Does the test lamp illuminate? | -- | Go to Step 3 | Go to Step 27 |
3 | Connect the test lamp between the ignition 3 voltage circuit and the ground circuit of the cruise control module. Does the test lamp illuminate? | -- | Go to Step 4 | Go to Step 28 |
4 |
Does the test lamp illuminate on any of the circuits? | -- | Go to Step 12 | Go to Step 5 |
5 |
Does the test lamp illuminate? | -- | Go to Step 6 | Go to Step 13 |
6 |
Does the test lamp illuminate? | -- | Go to Step 7 | Go to Step 15 |
7 |
Does the test lamp illuminate? | -- | Go to Step 8 | Go to Step 16 |
8 | Connect a test lamp between the TCC/cruise release switch signal circuit of the CCM and a good ground. Does the test lamp illuminate? | -- | Go to Step 9 | Go to Step 17 |
9 | Connect a test lamp between the stop lamp supply voltage signal circuit of the CCM and a good ground. Does the test lamp illuminate? | -- | Go to Step 18 | Go to Step 10 |
10 | Press the brake pedal while monitoring the test lamp. Does the test lamp illuminate? | -- | Go to Step 11 | Go to Step 19 |
11 | Measure the voltage at the cruise control engaged signal circuit. Does the voltage measure near the specified value? | B+ | Go to Step 21 | Go to Step 20 |
12 | Test the switch signal 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 33 | Go to Step 25 |
13 | Test the cruise on switch signal circuit for an open, for a short to ground, or for a high resistance. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition? | -- | Go to Step 33 | Go to Step 14 |
14 | Test the ignition 3 voltage circuit of the cruise control switch for an open or for a high resistance. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition? | -- | Go to Step 33 | Go to Step 25 |
15 | Test the cruise control set/coast switch signal circuit for an open, for a short to ground, or for a high resistance. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition? | -- | Go to Step 33 | Go to Step 25 |
16 | Test the cruise control resume/accelerate switch signal circuit for an open, for a short to ground, or for a high resistance. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition? | -- | Go to Step 33 | Go to Step 25 |
17 | Test the cruise control release switch signal circuit for an open or for a high resistance. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition? | -- | Go to Step 33 | Go to Step 22 |
18 | Test the stop lamp supply voltage 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 33 | Go to Stop Lamps Always On in Lighting Systems |
19 | Test the stop lamp signal circuit for an open or for a high resistance between the rear fuse block and the cruise control module. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition? | -- | Go to Step 33 | Go to Stop Lamps Inoperative in Lighting Systems |
20 | Test the cruise control engaged signal circuit for an open, for a high resistance, or 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 33 | Go to Step 24 |
21 | Test the vehicle speed signal circuit for an open or for a high resistance 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 33 | Go to Step 26 |
22 | Inspect the cruise control release switch for proper adjustment. Refer to Torque Converter Clutch/Cruise Control Release Switch Adjustment in Automatic Transaxle-4T65-E. Did you find and correct the condition? | -- | Go to Step 33 | Go to Step 23 |
23 | Inspect for poor connections at the harness connector of the cruise control release 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 33 | Go to Step 29 |
24 | 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 33 | Go to Step 30 |
25 | Inspect for poor connections at the harness connector of the cruise control switch. Refer to Testing for Intermittent Conditions and Poor Connections and to Connector Repairs in Wiring Systems. Did you find and correct the condition? | -- | Go to Step 33 | Go to Step 31 |
26 | 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 33 | Go to Step 32 |
27 | Repair the open in the ignition 3 voltage circuit of the cruise control module. Refer to Wiring Repairs in Wiring Systems. Did you complete the repair? | -- | Go to Step 33 | -- |
28 | Repair the open in the ground circuit of the cruise control module. Refer to Wiring Repairs in Wiring Systems. Did you complete the repair? | -- | Go to Step 33 | -- |
29 | Replace the cruise control release switch. Refer to Torque Converter Clutch/Cruise Control Release Switch Replacement in Automatic Transaxle-4T65-E. Did you complete the replacement? | -- | Go to Step 33 | -- |
30 |
Important: Program the replacement PCM. Replace the PCM. Refer to Powertrain Control Module Replacement in Engine Controls-3.8L. Did you complete the replacement? | -- | Go to Step 33 | -- |
31 | Replace the multifunction turn signal lever . Refer to Turn Signal Multifunction Switch Replacement in Steering Wheel and Column. Did you complete the replacement? | -- | Go to Step 33 | -- |
32 | Replace the cruise control module. Refer to Cruise Control Module Replacement . Did you complete the replacement? | -- | Go to Step 33 | -- |
33 | Operate the vehicle within the conditions for cruise control operation. Does the cruise control system operate correctly? | -- | System OK | Go to Step 2 |
