Cruise Control Inoperative/Malfunctioning 3.6L
Diagnostic Aids
Perform the following in order to avoid misdiagnosis:
| • | Ensure that the following cruise control switches are not stuck in the engaged position: |
| - | On/Off switch |
| - | Set/Coast switch |
| - | Resume/Accel switch |
| • | Inspect for proper operation of the stop lamps. Refer to Exterior Lighting Systems Description and Operation in Lighting Systems. |
| • | 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. |
Step | Action | Yes | No | ||||
|---|---|---|---|---|---|---|---|
Schematic Reference: Cruise Control Schematics Connector End View Reference: Engine Control Module Connector End Viewsin 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 |
Do any of the parameters listed above display ON? | Go to Step 5 | Go to Step 3 | ||||
3 |
Does the Cruise Set/Coast Switch parameter display On? | Go to Step 4 | Go to Step 6 | ||||
4 |
Does the Cruise Resume/Accel Switch parameter display On? | Go to Diagnostic Aids | Go to Step 9 | ||||
5 |
Do any of the parameters listed above display On? | Go to Step 7 | Go to Step 9 | ||||
6 |
Does the test lamp illuminate? | Go to Step 8 | Go to Step 11 | ||||
7 | Test the cruise control set/coast and resume/accel switch signal circuit for a short to voltage. Refer to Circuit Testingand to Wiring Repairs in Wiring Systems. Did you find and correct the condition? | Go to Step 14 | Go to Step 10 | ||||
8 | Test the cruise control set/coast and resume/accel switch signal circuit for an open, for a short to ground, for a short to voltage, or for a high resistance. Refer to Circuit Testing and to Wiring Repairs in Wiring Systems. Did you find and correct the condition? | Go to Step 14 | Go to Step 9 | ||||
9 | Inspect for poor connections at the harness connector of the cruise control switch. Refer to Testing for Intermittent Conditions and Poor Connections and to Connector Repairs in Wiring Systems. Did you find and correct the condition? | Go to Step 14 | Go to Step 12 | ||||
10 | Inspect for poor connections at the harness connector of the engine control module (ECM). Refer to Testing for Intermittent Conditions and Poor Connections and to Connector Repairsin Wiring Systems. Did you find and correct the condition? | Go to Step 14 | Go to Step 13 | ||||
11 | Repair the open, the short to ground, or the high resistance in the ignition 1 voltage circuit. Refer to Wiring Repairsin Wiring Systems. Did you complete the repair? | Go to Step 14 | -- | ||||
12 | 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 14 | -- | ||||
13 | 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 14 | -- | ||||
14 | Operate the cruise control system in order to verify the repair. Does the cruise control system operate properly? | System OK | Go to Step 2 | ||||
Cruise Control Inoperative/Malfunctioning 4.6L
Diagnostic Aids
Perform the following in order to avoid a misdiagnosis:
| • | Ensure that the following cruise control switches are not stuck in the engaged position: |
| - | On/off switch |
| - | Set/coast switch |
| - | Resume/accel switch |
| • | Inspect for proper operation of the stop lamps. Refer to Exterior Lighting Systems Description and Operation in Lighting Systems. |
| • | 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. |
Step | Action | Values | Yes | No |
|---|---|---|---|---|
Schematic Reference: Cruise Control Schematics Connector End View Reference: Engine Control Module Connector End Views in Engine Controls - 4.6L (LH2) | ||||
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 Control Switch parameter display Off? | -- | Go to Step 3 | Go to Step 8 |
3 |
Does the Cruise Control Switch parameter display On? | -- | Go to Step 4 | Go to Step 9 |
4 |
Does the Cruise Control Switch parameter display Set? | -- | Go to Step 5 | Go to Step 10 |
5 |
Does the Cruise Control Switch parameter display Resume? | -- | Go to Step 6 | Go to Step 10 |
6 | Do the stop lamps operate properly? | -- | Go to Step 7 | Go to Stop Lamps Always On or to Stop Lamps Inoperative in Lighting Systems |
7 |
Does the Stoplamp Pedal Switch parameter display Applied? | -- | Go to Diagnostic Aids | Go to Step 12 |
8 |
Does the Cruise Control Switch parameter display Off? | -- | Go to Step 15 | Go to Step 13 |
9 |
Does the test lamp illuminate? | -- | Go to Step 11 | Go to Step 17 |
10 |
Important: The cruise control on/off switch must be turned ON in order to correctly view the set/coast resistance value with the DMM.
Do the cruise control function switch resistance values measure between the specified values? | Off = O.L. On = 7.8 K ohms to 8.6 K ohms Resume = 2.7 K ohms to 3.0 K ohms Set = 1.2 K ohms to 1.3 K ohms | Go to Step 14 | Go to Step 15 |
11 |
Important: The cruise control on/off switch must be turned ON in order to correctly view the set/coast resistance value with the DMM.
Do the cruise control function switch resistance values measure between the specified values? | Off = O.L. On = 7.8 K ohms to 8.6 K ohms Resume = 2.7 K ohms to 3.0 K ohms Set = 1.2 K ohms to 1.3 K ohms | Go to Step 16 | Go to Step 15 |
12 | Test the stop lamp switch signal circuit for an open or for a high resistance. Refer to Circuit Testing and to Wiring Repairs in Wiring Systems. Did you find and correct the condition? | -- | Go to Step 20 | Go to Step 16 |
13 | Test the cruise control set/coast and resume/accelerate switch signal circuit for a short to voltage. Refer to Circuit Testing and to Wiring Repairs in Wiring Systems. Did you find and correct the condition? | -- | Go to Step 20 | Go to Step 16 |
14 | Test the cruise control set/coast and resume/accelerate switch signal circuit for an open, for a short to voltage, for a short to ground, or for a high resistance. Refer to Circuit Testing and to Wiring Repairs in Wiring Systems. Did you find and correct the condition? | -- | Go to Step 20 | Go to Step 16 |
15 | Inspect for poor connections at the harness connector of the cruise control switch. Refer to Testing for Intermittent Conditions and Poor Connections and to Connector Repairs in Wiring Systems. Did you find and correct the condition? | -- | Go to Step 20 | Go to Step 18 |
16 | Inspect for poor connections at the harness connector of the engine control module (ECM). Refer to Testing for Intermittent Conditions and Poor Connections and to Connector Repairs in Wiring Systems. Did you find and correct the condition? | -- | Go to Step 20 | Go to Step 19 |
17 | Repair the open, the short to ground, or the high resistance in the ignition 1 voltage circuit. Refer to Wiring Repairs in Wiring Systems. Did you complete the repair? | -- | Go to Step 20 | -- |
18 | Replace the cruise control switch. Refer to Steering Wheel Control Switch Assembly Replacement in Steering Wheel and Column. Did you complete the replacement? | -- | Go to Step 20 | -- |
19 | 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 20 | -- |
20 | Operate the vehicle with in the conditions for cruise control operation. Does the cruise control system operate properly? | -- | System OK | Go to Step 2 |
