Cruise Control Inoperative Gasoline Engine
Diagnostic Aids
Important: Perform the following in order to avoid misdiagnosis.
• Inspect for proper operation of brake lamps and clutch switch. • 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 |
|---|---|---|---|---|
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 30 |
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 31 |
4 |
Does the test lamp illuminate on any of the circuits? | -- | Go to Step 14 | Go to Step 5 |
5 |
Does the test lamp illuminate? | -- | Go to Step 6 | Go to Step 15 |
6 |
Does the test lamp illuminate? | -- | Go to Step 7 | Go to Step 17 |
7 |
Does the test lamp illuminate? | -- | Go to Step 8 | Go to Step 18 |
8 | Probe the TCC/ stop lamp switch cruise release 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 illuminate? | -- | Go to Step 20 | Go to Step 10 |
10 | Probe the TCC/ stop lamp switch 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 VCM signal (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 for proper speedometer operation. Does the speedometer operate properly? | -- | Go to Step 24 | Go to Symptoms |
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 36 | Go to Step 28 |
15 | Test the on/off circuit for a open, high resistance or short to ground and the 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 36 | Go to Step 16 |
16 | Test the ignition positive voltage circuit of the cruise control switch for a open, high resistance or short to ground between the IP fuse block 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 36 | Go to Step 28 |
17 | Test the set/coast 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 36 | Go to Step 28 |
18 | Test the resume/accelerate 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 36 | Go to Step 28 |
19 | Test the TCC/stop lamp switch cruise release 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 36 | Go to Step 25 |
20 | Test the TCC/stop lamp switch cruise release 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 36 | Go to Step 26 |
21 | Test the TCC/stop lamp switch stop lamp 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 36 | Go to Step 26 |
22 | Test the TCC/stop lamp switch stop lamp 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 36 | Go to Step 25 |
23 | Test the VCM signal (cruise engaged) circuit for a open, high resistance, or a short to voltage. Refer to Circuit Testing and Wiring Repairs Wiring Systems. Did you find and correct the condition? | -- | Go to Step 36 | Go to Step 27 |
24 | Test the speed sensor circuit for an open or a high resistance between the VCM 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 36 | Go to Step 27 |
25 | Test the multifunction stop lamp switch positive battery voltage circuit for a open, high resistance or a short to ground. Refer to Circuit Testing and Wiring Repairs Did you find and correct the condition? | -- | Go to Step 36 | Go to Step 26 |
26 | Inspect for poor connections at the harness connector of the TCC/ 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 36 | Go to Step 32 |
27 | 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 36 | Go to Step 33 |
28 | 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 36 | Go to Step 34 |
29 | 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 36 | Go to Step 35 |
30 | 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 36 | -- |
31 | Repair the ground circuit of the cruise control module. Refer to Wiring Repairs in Wiring Systems. Did you complete the repair? | -- | Go to Step 36 | -- |
32 | Replace the TCC/ stop lamp switch. Refer to Stop Lamp Switch Replacement . Did you complete the replacement? | -- | Go to Step 36 | -- |
33 | Replace the PCM. Refer to VCM Replacement/Programming 4.3L, VCM Replacement/Programming 5.0L/5.7L, VCM Replacement/Programming 7.4L in Engine Controls. Did you complete the replacement? | -- | Go to Step 36 | -- |
34 | Replace the cruise control switch. Refer to Multifunction, Turn Signal, and Hazard Switch Replacement - On Vehicle in Steering Wheel and Column - Tilt. Did you complete the replacement? | -- | Go to Step 36 | -- |
35 | Replace the cruise control module. Refer to Cruise Control Module Replacement . Did you complete the replacement? | -- | Go to Step 36 | -- |
36 | Operate the vehicle within the conditions for cruise control operation. Does the cruise control system operate correctly? | -- | System OK | Go to Step 2 |
Cruise Control Inoperative Diesel Engine
Diagnostic Aids
Important: Perform the following in order to avoid misdiagnosis.
• Inspect for proper operation of brake lamps and brake switch. • Inspect the speedometer for proper operation.
Conditions for Enabling Cruise Control
The vehicle speed is greater than 40 km/h (25 mph).
Step | Action | Yes | No |
|---|---|---|---|
1 | Did you perform A Diagnostic System Check - Cruise Control? | Go to Step 2 | |
2 |
Does the test lamp illuminate on any of the circuits? | Go to Step 10 | Go to Step 3 |
3 |
Does the test lamp illuminate? | Go to Step 4 | Go to Step 11 |
4 |
Does the test lamp illuminate? | Go to Step 5 | Go to Step 13 |
5 |
Does the test lamp illuminate? | Go to Step 6 | Go to Step 14 |
6 | Probe the TCC/ stop lamp switch cruise control release signal circuit with a test lamp connected to a good ground. Does the test lamp illuminate? | Go to Step 7 | Go to Step 15 |
7 | Press the brake pedal while monitoring the test lamp. Does the test lamp illuminate? | Go to Step 16 | Go to Step 8 |
8 | Probe the TCC/ stop lamp switch stop lamp signal circuit with a test lamp that is connected to a good ground. Does the test lamp illuminate? | Go to Step 17 | Go to Step 9 |
9 | Press the brake pedal while monitoring the test lamp. Does the test lamp illuminate? | Go to Step 22 | Go to Step 18 |
10 | 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 26 | Go to Step 21 |
11 | Test the cruise ON 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 26 | Go to Step 12 |
12 | Test the ignition positive voltage circuit of the cruise control switch for a open, high resistance or short to ground between the IP fuse block 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 26 | Go to Step 21 |
13 | Test the set/coast switch signal circuit for an open or 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 26 | Go to Step 21 |
14 | Test the resume/accelerate switch signal circuit for an open or 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 26 | Go to Step 21 |
15 | Test the TCC/ stop lamp switch cruise control release 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 26 | Go to Step 19 |
16 | Test the TCC/stop lamp switch cruise control 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 26 | Go to Step 20 |
17 | Test the TCC/stop lamp switch stop lamp 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 26 | Go to Step 20 |
18 | Test the TCC/stop lamp switch stop lamp 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 26 | Go to Step 19 |
19 | Test the ignition positive voltage circuit of the TCC/ stop lamp switch 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 26 | Go to Step 20 |
20 | Inspect for poor connections at the harness connector of the TCC/ 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 26 | Go to Step 23 |
21 | 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 26 | Go to Step 24 |
22 | 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 26 | Go to Step 25 |
23 | Replace the TCC/stop lamp switch. Refer to Stop Lamp Switch Replacement in Brakes. Did you complete the replacement? | Go to Step 26 | -- |
24 | Replace the multi function turn signal lever. Refer to Multifunction, Turn Signal, and Hazard Switch Replacement - On Vehicle in Steering Wheel and Column - Tilt. Did you complete the replacement? | Go to Step 26 | -- |
25 | Replace the PCM. Refer to Powertrain Control Module Replacement/Programming . Did you complete the replacement? | Go to Step 26 | -- |
26 | Operate the vehicle within the conditions for cruise control operation. Does the cruise control operate correctly? | System OK | Go to Step 2 |
