Perform the following in order to avoid misdiagnosis:
• | Inspect for proper operation of the stop lamps. Refer to Exterior Lighting Systems Description and Operation in Lighting Systems. |
• | Electromagnetic interference (EMI) on the speed sensor signal circuit may cause erratic cruise control operation. |
For an intermittent condition, refer to Testing for Intermittent Conditions and Poor Connections in Wiring Systems.
• | The vehicle speed is greater than 40 km/h (25 mph). |
• | The vehicle is not in PARK, REVERSE, NEUTRAL, or 1st gear. |
• | The system voltage is between 12 volts and 16 volts. |
Step | Action | Yes | No |
---|---|---|---|
Schematic Reference: Cruise Control Schematics Connector End View Reference: Lighting Systems Connector End Views or to Engine Control Module Connector End Views in Engine Controls - 3.6L (LY7) | |||
1 | Did you perform the Diagnostic System Check - Vehicle? | Go to Step 2 | Go to Diagnostic System Check - Vehicle in Vehicle DTC Information |
2 |
Does the Cruise On/Off Switch parameter display Off? | Go to Step 3 | Go to Step 6 |
3 |
Does the Cruise On/Off Switch parameter display On? | Go to Step 4 | Go to Step 7 |
4 |
Does the Cruise Set/Coast Switch parameter Display On? | Go to Step 5 | Go to Step 17 |
5 |
Does the Cruise Resume/Accel. Switch parameter Display On? | Go to Step 8 | Go to Step 18 |
6 |
Does the Cruise On/Off Switch parameter display On? | Go to Step 12 | Go to Step 20 |
7 |
Does the test lamp illuminate? | Go to Step 10 | Go to Step 13 |
8 | Do the stop lamps operate properly? | Go to Step 9 | Go to Stop Lamps Inoperative or to Stop Lamps Always On in Lighting Systems |
9 |
Does the Stoplamp Pedal Switch parameter Display Applied? | Go to Diagnostic Aids | Go to Step 11 |
10 |
Does the Cruise On/Off Switch parameter display On? | Go to Step 20 | Go to Step 16 |
11 | Test the stop lamp signal circuit for an open or for a high resistance between the stop lamp switch and the engine control module (ECM). Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition? | Go to Step 24 | Go to Step 21 |
12 | Test the cruise control on 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 24 | Go to Step 21 |
13 | Test the cruise control on switch 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 24 | Go to Step 14 |
14 | Test the cruise control set/coast switch 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 24 | Go to Step 15 |
15 | Test the cruise control resume/accelerate switch 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 24 | Go to Step 19 |
16 | Test the cruise control 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 24 | Go to Step 21 |
17 | Test the cruise control set/coast 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 24 | Go to Step 20 |
18 | Test the cruise control resume/accelerate 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 24 | Go to Step 20 |
19 | Repair the open, the high resistance, or the short to ground in the ignition 3 voltage circuit. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you complete the repair? | Go to Step 24 | -- |
20 | 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 24 | Go to Step 22 |
21 | Inspect for poor connections at the harness connector of the ECM. 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 24 | Go to Step 23 |
22 | 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 24 | -- |
23 | Replace the ECM. Refer to Control Module References in Computer/Integrating Systems for replacement, setup, and programming. Did you complete the replacement? | Go to Step 24 | -- |
24 | Operate the vehicle within the conditions for cruise control operation. Does the cruise control system operate properly? | System OK | Go to Step 2 |
Important: Perform the following in order to avoid misdiagnosis.
• | Inspect for proper operation of the brake lamps. |
• | Inspect for proper operation of the transmission range switch. |
• | Inspect throttle linkage for mechanical binding which could cause the system to malfunction. |
Step | Action | Value(s) | Yes | No |
---|---|---|---|---|
Schematic Reference: Cruise Control Schematics | ||||
1 | Did you perform the Diagnostic System Check - Vehicle? | -- | Go to Step 2 | Go to Diagnostic System Check - Vehicle in Vehicle DTC Information |
2 |
Does the test lamp illuminate? | -- | Go to Step 3 | Go to Step 29 |
3 | Connect the test lamp between the ignition positive voltage circuit and 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 signal circuits? | -- | Go to Step 13 | Go to Step 5 |
5 |
Does the test lamp illuminate? | -- | Go to Step 6 | Go to Step 14 |
6 |
Does the test lamp illuminate? | -- | Go to Step 7 | Go to Step 16 |
7 |
Does the test lamp illuminate? | -- | Go to Step 8 | Go to Step 17 |
8 | Connect the test lamp between the cruise control release signal circuit and a good ground. Does the test lamp illuminate? | -- | Go to Step 19 | Go to Step 18 |
9 | Connect the test lamp between the stop lamp signal circuit and a good ground. Does the test lamp illuminate? | -- | Go to Step 20 | 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 21 |
11 | Measure the voltage at the cruise control engaged signal circuit. Does the voltage measure near the specified value? | B+ | Go to Step 12 | Go to Step 22 |
12 | Check the speedometer for proper operation. Does the speedometer operate properly? | -- | Go to Step 23 | Go to Speedometer and/or Odometer Inaccurate or Inoperative in Instrument Panel, Gages and Console |
13 | Test the suspected 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 35 | Go to Step 27 |
14 | Test the cruise control On/Off 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 35 | Go to Step 15 |
15 | Test the ignition positive voltage circuit of the cruise control on/off 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 35 | Go to Step 27 |
16 | Test the cruise control set/coast 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 35 | Go to Step 27 |
17 | Test the cruise control resume/accelerate 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 35 | Go to Step 27 |
18 | 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 35 | Go to Step 24 |
19 | Test the cruise control release 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 35 | Go to Step 9 |
20 | 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 35 | Go to Stop Lamps Always On in Lighting Systems |
21 | Test the stop lamp switch signal circuit for an open or for a high resistance between the center console 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 35 | Go to Stop Lamps Inoperative in Lighting Systems |
22 | Test the cruise 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 35 | Go to Step 26 |
23 | Test the vehicle speed signal circuit for an open or for a high resistance between the powertrain control module (PCM) 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 35 | Go to Step 28 |
24 | Inspect the cruise control release switch for proper adjustment. Refer to Cruise Release Switch Adjustment in Cruise Control. Did you find and correct the condition? | -- | Go to Step 35 | Go to Step 25 |
25 | 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 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 cruise control release switch. Refer to Cruise Control Release Switch Replacement . Did you complete the replacement? | -- | Go to Step 35 | -- |
32 | Replace the PCM. Refer to Control Module References in Computer/Integrating Systems for replacement, setup, and programming. Did you complete the replacement? | -- | Go to Step 35 | -- |
33 | Replace the cruise control switch. Refer to Turn Signal Multifunction Switch Replacement in Steering Wheel and Column. Did you complete the replacement? | -- | Go to Step 35 | -- |
34 | Replace the cruise control module. Refer to Control Module References in Computer/Integrating Systems for replacement, setup, and programming . Did you complete the replacement? | -- | Go to Step 35 | -- |
35 |
Does the cruise control system operate correctly? | -- | System OK | Go to Step 2 |