Important: To avoid misdiagnosis:
• Inspect for proper operation of the brake lamps. • Inspect throttle linkage for mechanical binding which could cause
the system to malfunction. • Inspect cruise control adjustment, should have minimum slack. • Inspect for stored Diagnostic Trouble Codes DTCs in the PCM. • EMI on the speed sensor signal circuit may cause erratic cruise
control operation.
Conditions for Enabling Cruise Control
| • | When vehicle speed is more than 40 km/h (25 mph) |
| • | When PARK, REVERSE, NEUTRAL, or 1st gear IS NOT indicated. |
| • | When an over/undercharged battery condition DOES NOT exist. |
| • | With normal engine RPM. |
| • | Without high engine RPM (fuel cut-off). |
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 39 |
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 40 |
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 20 |
7 |
Does the test lamp illuminate? | -- | Go to Step 8 | Go to Step 21 |
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 10 | Go to Step 9 |
9 |
Does the test lamp illuminate? | -- | Go to Step 31 | Go to Step 24 |
10 | Press the brake pedal while monitoring the test lamp. Does the test lamp illuminate? | -- | Go to Step 23 | Go to Step 11 |
11 | Probe the stoplamp switch signal circuit with a test lamp that is connected to a good ground. Does the test lamp illuminate? | -- | Go to Step 25 | Go to Step 12 |
12 | Press the brake pedal while monitoring the test lamp. Does the test lamp illuminate? | -- | Go to Step 13 | Go to Step 26 |
13 | Probe the cruise inhibit signal circuit with a test lamp that is connected to battery positive. Does the test lamp illuminate? | -- | Go to Step 27 | Go to Step 14 |
14 | Use a scan tool in order to command the cruise disable ON. Does the test lamp illuminate? | -- | Go to Step 15 | Go to Step 28 |
15 | Probe the cruise engaged output signal 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 29 |
16 | Check the speedometer for proper operation. Does the speedometer operate properly? | -- | Go to Step 30 | Go to Symptoms - Instrument Panel, Gages and Console in Instrument Panel, Gauges and Console |
17 | Test the 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 46 | Go to Step 36 |
18 | Test the on/off signal circuit for a open, high resistance or short to ground and the cruise control set/coast, resume/accel and cruise release 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 19 |
19 | Test the ignition positive voltage circuit of the cruise control switch for an 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 46 | Go to Step 36 |
20 | Test the set/coast 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 46 | Go to Step 36 |
21 | Test the resume/accel 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 46 | Go to Step 36 |
22 | Test the cruise control 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 46 | Go to Step 31 |
23 | Test the cruise control 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 46 | Go to Step 31 |
24 | Test the cruise control release signal circuit between the cruise release switch and the steering wheel 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 46 | Go to Step 36 |
25 | Test the stoplamp 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 32 |
26 | Test the stoplamp switch 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 46 | Go to Step 32 |
27 | Test the cruise inhibit signal circuit 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 35 |
28 | Test the cruise inhibit signal circuit for a open, 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 |
29 | Test the cruise engaged output signal circuit for a open, 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 46 | Go to Step 35 |
30 | Test the VSS signal circuit for an open or 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 46 | Go to Step 35 |
31 | Inspect the TCC/Brake switch for proper adjustment. Refer to Cruise Release Switch Adjustment in Hydraulic Brakes. Did you find and correct the condition? | -- | Go to Step 46 | Go to Step 33 |
32 | Inspect the stoplamp/automatic transmission shift lock control 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 34 |
33 | Inspect for poor connections at the harness connector of the TCC/Brake 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 stoplamp/automatic transmission shift lock 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 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 if the TCC/Brake switch. Refer to Wiring Repairs in Wiring Systems. Did you complete the repair? | -- | Go to Step 46 | -- |
39 | 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 | -- |
40 | 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 | -- |
41 | Replace the TCC/Brake (cruise release) switch. Refer to Cruise Control Release Switch Replacement . Did you complete the replacement? | -- | Go to Step 46 | -- |
42 | Replace the stoplamp/automatic transmission shift lock control switch. Refer to Stop Lamp Switch Replacement in Hydraulic Brakes. Did you complete the replacement? | -- | Go to Step 46 | -- |
43 |
Important: The powertrain control module must be reprogrammed before replacement. Refer to Powertrain Control Module Programming in Engine Controls. Replace the PCM. Refer to Powertrain Control Module Replacement in Engine Controls . Did you complete the replacement? | -- | Go to Step 46 | -- |
44 | Replace the cruise control switch . Refer to Steering Wheel Control Switches Replacement . 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 |
