Diagnostic Aids
Important: Perform the following in order to avoid misdiagnosis.
• Inspect for proper operation of brake lamps and clutch switch,
if equipped. • 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 the Cruise Control Diagnostic System Check? | -- | Go to Step 2 | |
2 |
Does the test lamp illuminate? | -- | Go to Step 3 | Go to Step 38 |
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 39 |
4 |
Does the test lamp illuminate on any of the circuits? | -- | Go to Step 18 | Go to Step 5 |
5 |
Does the test lamp illuminate? | -- | Go to Step 6 | Go to Step 19 |
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 cruise control release signal circuit with a test lamp that is connected to a good ground. Does the test lamp illuminate? | -- | Go to Step 13 | Go to Step 9 |
9 | Is the vehicle equipped with a manual transmission? | -- | Go to Step 10 | Go to Step 11 |
10 |
Does the test lamp illuminate? | -- | Go to Step 25 | Go to Step 11 |
11 |
Does the test lamp illuminate? | -- | Go to Step 23 | Go to Step 31 |
12 | Press the brake pedal while monitoring the test lamp. Does the test lamp illuminate? | -- | Go to Step 26 | Go to Step 13 |
13 | Probe the stop lamp switch signal circuit with a test lamp that is connected to a good ground. Does the test lamp illuminate? | -- | Go to Step 27 | Go to Step 14 |
14 | Press the brake pedal while monitoring the test lamp. Does the test lamp illuminate? | -- | Go to Step 15 | Go to Step 25 |
15 | Probe the cruise control engaged signal circuit with a test lamp that is connected to a good ground. Does the test lamp illuminate? | -- | Go to Step 16 | Go to Step 29 |
16 |
Does the test lamp illuminate? | -- | Go to Step 17 | Go to Step 30 |
17 | Check the speedometer for proper operation. Does the speedometer operate properly? | -- | Go to Step 32 | Go to Symptoms - Instrument Panel, Gages and Console in Instrument Panel, Gauges and Consoles |
18 | 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 46 | Go to Step 36 |
19 | Test the cruise control on signal circuit for an open or a high resistance and the cruise control set/coast, resume accel 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 46 | Go to Step 20 |
20 | Test the ignition positive voltage circuit of the cruise control switch for an open or high resistance. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition? | -- | Go to Step 46 | Go to Step 36 |
21 | Test the cruise control set/coast 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 46 | Go to Step 36 |
22 | Test the cruise control resume/accelerate 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 46 | Go to Step 36 |
23 | Check the TCC/Brake switch for proper adjustment. Refer to Stop Lamp Switch Adjustment in Hydraulic Brakes. Did you find and correct the condition? | -- | Go to Step 46 | Go to Step 25 |
24 | Check the stop lamp switch for proper adjustment. Refer to Stop Lamp Switch Adjustment in Hydraulic Brakes. Did you find and correct the condition? | -- | Go to Step 46 | Go to Step 28 |
25 | Test the TCC Brake 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 46 | Go to Step 33 |
26 | 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 46 | Go to Step 33 |
27 | 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 46 | Go to Step 34 |
28 | 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 46 | Go to Step 34 |
29 | Test the cruise control engaged signal 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 46 | Go to Step 35 |
30 | Test the cruise inhibit signal 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 46 | Go to Step 35 |
31 | Test the ignition positive voltage circuit of the TCC/Brake switch for a open, a high resistance. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition? | -- | Go to Step 46 | Go to Step 33 |
32 | Test the speed sensor circuit for an open or a high resistance between the PCM and cruise control module. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition? | -- | Go to Step 46 | Go to Step 37 |
33 | Inspect for poor connections at the harness connector of the appropriate 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 46 | Go to Step 41 |
34 | 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 46 | Go to Step 42 |
35 | 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 46 | Go to Step 43 |
36 | 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 46 | Go to Step 44 |
37 | 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 46 | Go to Step 45 |
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 46 | -- |
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 46 | -- |
40 | Repair the ignition positive voltage circuit of the TCC/Brake switch harness connector. Did you complete the repair? | -- | Go to Step 46 | -- |
41 | Replace the appropriate switch. Refer to Stop Lamp Switch Replacement in Hydraulic Brakes or CPP Switch Replacement in Clutch. Did you complete the replacement? | -- | Go to Step 46 | -- |
42 | Replace the stop lamp switch. Refer to Stop Lamp Switch Replacement in Hydraulic Brakes. Did you complete the replacement? | -- | Go to Step 46 | -- |
43 |
Important: The PCM must be reprogrammed after replacement. Refer to Powertrain Control Module Programming in Engine Controls - 2.2L or Powertrain Control Module Programming in Engine Controls - 2.4L. Replace the PCM. Refer to Powertrain Control Module Replacement in Engine Controls - 2.2L or Powertrain Control Module Replacement in Engine Controls - 2.4L. Did you complete the replacement? | -- | Go to Step 46 | -- |
44 | Replace the cruise control switch. Refer to Multifunction, Turn Signal, and Hazard Switch Replacement - On Vehicle . Did you complete the replacement? | -- | Go to Step 46 | -- |
45 | Replace the cruise control module. Refer to Cruise Control Module Replacement . Did you complete the replacement? | -- | Go to Step 46 | -- |
46 | Operate the vehicle within the conditions for cruise control operation. Does the cruise control system operate correctly? | -- | System OK | Go to Step 2 |
