Cruise Control Inoperative W/O ElectronicThrottle Control
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 |
|---|---|---|---|---|
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 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 |
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 brake/clutch 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 | Depress the brake pedal while monitoring the test lamp. Does the test lamp illuminate? | -- | Go to Step 20 | Go to Step 10 |
10 | Probe the brake switch 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 | Depress 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 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 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 Cluster in Instrument Panel, Gages and Consoles |
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 on/off 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 16 |
16 | Test the ignition positive voltage circuit for an open or high resistance 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 set/coast 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 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 35 | Go to Step 27 |
19 | Test the (TCC) brake/clutch 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/clutch 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 35 | Go to Step 25 |
21 | 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 35 | Go to Step 25 |
22 | Test the brake switch 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 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 35 | Go to Step 26 |
24 | 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 35 | Go to Step 28 |
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 32 |
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 33 |
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 34 |
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 . Did you complete the replacement? | -- | Go to Step 35 | -- |
32 | Replace the PCM. Refer to Powertrain Control Module Replacement in Engine Controls. Did you complete the replacement? | -- | Go to Step 35 | -- |
33 | Replace the cruise control switch. Refer to Multifunction, Turn Signal, and Hazard Switch Replacement - On Vehicle . Did you complete the replacement? | -- | Go to Step 35 | -- |
34 | Replace the cruise control module. Refer to Cruise Control Module Replacement . 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 |
Cruise Control Inoperative W/ Electronic Throttle Control
Diagnostic Aids
Important: Perform the following in order to avoid misdiagnosis.
• Inspect for proper operation of brake lamps and clutch switch,
if equipped. • 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 | 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 on any of the circuits? | Go to Step 16 | Go to Step 3 |
3 |
Does the test lamp illuminate? | Go to Step 4 | Go to Step 17 |
4 |
Does the test lamp illuminate? | Go to Step 5 | Go to Step 19 |
5 |
Does the test lamp illuminate? | Go to Step 6 | Go to Step 20 |
6 | 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 23 | Go to Step 9 |
7 | Press the brake pedal while monitoring the test lamp. Does the test lamp illuminate? | Go to Step 8 | Go to Step 21 |
8 | Is the vehicle equipped with a manual transmission? | Go to Step 9 | Go to Step 11 |
9 |
Does the test lamp illuminate? | Go to Step 10 | Go to Step 14 |
10 | Press the clutch pedal while monitoring the test lamp. Does the test lamp illuminate? | Go to Step 27 | Go to Step 11 |
11 | Probe the brake switch signal circuit of the ECM harness connector with a test lamp connected to a good ground. Does the test lamp illuminate? | Go to Step 12 | Go to Step 15 |
12 | Press the brake pedal while monitoring the test lamp. Does the test lamp illuminate? | Go to Step 24 | Go to Step 13 |
13 | Check the speedometer for proper operation. Does the speedometer operate properly? | Go to Step 33 | Go to Symptoms - Instrument Cluster in Instrument Panel, Gages and Console |
14 |
Does the test lamp illuminate? | Go to Step 28 | Go to Step 26 |
15 |
Does the test lamp illuminate? | Go to Step 25 | Go to Step 29 |
16 | 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 38 | Go to Step 32 |
17 | Test the on/off signal circuit for a open, high resistance or short to ground and the S/C and R/A 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 38 | Go to Step 18 |
18 | Test the ignition positive voltage circuit of the cruise control 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 38 | Go to Step 32 |
19 | 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 38 | Go to Step 32 |
20 | 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 38 | Go to Step 32 |
21 | Test the 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 38 | Go to Step 22 |
22 | Test the stop lamp 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 38 | Go to Step 31 |
23 | 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 38 | Go to Step 31 |
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 38 | Go to Step 31 |
25 | Test the brake switch signal circuit of the PCM harness Repair the open in the ignition positive voltage 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 38 | Go to Step 31 |
26 | Test the CPP 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 38 | Go to Step 30 |
27 | Test the CPP signal circuit of the PCM harness 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 38 | Go to Step 30 |
28 | Repair the open in the ignition positive voltage circuit of the CPP switch. Did you complete the repair? | Go to Step 38 | -- |
29 | Repair the open in the ignition positive voltage circuit of the stop lamp switch. Did you complete the repair? | Go to Step 38 | -- |
30 | Inspect for poor connections at the harness connector of the CPP 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 38 | Go to Step 34 |
31 | 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 38 | Go to Step 35 |
32 | 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 38 | Go to Step 36 |
33 | Inspect for poor connections at the harness connector of the Throttle Actuator Control (TAC) 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 38 | Go to Step 37 |
34 | Replace the CPP switch. Refer to Clutch Pedal Engine Start Switch Replacement . Did you complete the replacement? | Go to Step 38 | -- |
35 | Replace the Stop lamp switch. Refer to Stop Lamp Switch Replacement . Did you complete the replacement? | Go to Step 38 | -- |
36 | Replace the cruise control switch. Refer to Multifunction, Turn Signal, and Hazard Switch Replacement - On Vehicle . Did you complete the replacement? | Go to Step 38 | -- |
37 | Replace the Throttle Actuator Control (TAC) Module. Refer to Electronic Throttle Actuator Control Module Replacement . Did you complete the replacement? | Go to Step 38 | -- |
38 | Operate the vehicle within the conditions for cruise control operation. Does the cruise control system operate correctly? | System OK | Go to Step 2 |
