Cruise Control Inoperative/Malfunctioning 3.8L
Diagnostic Aids
Caution: Refer to SIR Caution in the Preface section.
Disable the inflatable restraint steering wheel module when performing this diagnostic table. Refer to SIR Disabling and Enabling in SIR.
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 |
| • | With a scan tool, observe the cruise control function switch parameters, in the Body and Accessories, Cruise Control data list, while rotating the steering wheel to both steering stops and individually activating each cruise control function switch separately. This will help eliminate the possibility of an internally shorted inflatable restraint steering wheel module coil. |
| • | Inspect for proper operation of the stop lamps. Refer to Exterior Lighting Systems Description and Operation in Lighting Systems. |
| • | Electromagnetic interference (EMI) on the vehicle speed sensor (VSS) 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: Powertrain Control Module Connector End Views in Engine Controls - 3.8L | ||||||||||||
1 | Did you perform the Diagnostic System Check - Vehicle? | -- | Go to Step 2 | Go to Diagnostic System Check - Vehicle in Vehicle DTC Information | ||||||||
2 | Is DTC P0573 current in the powertrain control module (PCM)? | -- | Go to DTC P0573 in Lighting Systems | Go to Step 3 | ||||||||
3 |
Does the Cruise On/Off Switch parameter display Off? | -- | Go to Step 4 | Go to Step 8 | ||||||||
4 |
Does the Cruise On/Off Switch parameter display On? | -- | Go to Step 5 | Go to Step 9 | ||||||||
5 |
Does the Cruise Set/Coast Switch parameter display On? | -- | Go to Step 6 | Go to Step 10 | ||||||||
6 |
Does the Cruise Resume/Accel. Switch parameter display On? | -- | Go to Step 7 | Go to Step 10 | ||||||||
7 |
Does the voltage measure greater than the specified value? | 8.5 V | Go to Step 14 | Go to Step 16 | ||||||||
8 |
Does the Cruise On/Off Switch parameter display Off? | -- | Go to Step 18 | Go to Step 12 | ||||||||
9 |
Does the test lamp illuminate? | -- | Go to Step 11 | Go to Step 25 | ||||||||
10 |
Important: The cruise control on/off switch must be turned ON in order to correctly view the set/coast and the resume/accel switch resistance values with the DMM.
Do the cruise control function switch resistance values measure between the specified values? | Off = O.L. On = 7.8 K-8.6 K ohms Resume = 2.7 K-3.0 K ohms Set = 1.2 K-1.3 K ohms | Go to Step 13 | Go to Step 17 | ||||||||
11 |
Important: The cruise control on/off switch must be turned ON in order to correctly view the set/coast and the resume/accel switch resistance values with the DMM.
Do the cruise control function switch resistance values measure between the specified values? | Off = O.L. On = 7.8 K-8.6 K ohms Resume = 2.7 K-3.0 K ohms Set = 1.2 K-1.3 K ohms | Go to Step 13 | Go to Step 17 | ||||||||
12 | 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 30 | Go to Step 23 | ||||||||
13 | Test the cruise control set/coast and resume/accelerate switch signal circuit for the following:
Refer to Circuit Testing and to Wiring Repairs in Wiring Systems. Did you find and correct the condition? | -- | Go to Step 30 | Go to Step 23 | ||||||||
14 | Test the vehicle speed 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 30 | Go to Step 15 | ||||||||
15 | With a DMM, measure the voltage of the stop lamp switch signal circuit. Does the voltage measure greater than the specified value? | 8.5 V | Go to Step 24 | Go to Step 26 | ||||||||
16 | Test the vehicle speed 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 30 | Go to Step 23 | ||||||||
17 | Test the ignition 1 between C277 and the cruise control switch assembly for the following:
Refer to Circuit Testing and to Wiring Repairs in Wiring Systems. Did you find and correct the condition? | -- | Go to Step 30 | Go to Step 20 | ||||||||
18 | Test the cruise control on 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 30 | Go to Step 19 | ||||||||
19 | Test the cruise control set/coast and resume/accelerate switch signal circuit for a short to voltage between C277 and the cruise control switch assembly. Refer to Circuit Testing and to Wiring Repairs in Wiring Systems. Did you find and correct the condition? | -- | Go to Step 30 | Go to Step 22 | ||||||||
20 | Test the cruise control set/coast and resume/accelerate switch signal circuit between C277 and the cruise control switch assembly for the following:
Refer to Circuit Testing and to Wiring Repairs in Wiring Systems. Did you find and correct the condition? | -- | Go to Step 30 | Go to Step 21 | ||||||||
21 | Test the cruise control on switch signal circuit for the following:
Refer to Circuit Testing and to Wiring Repairs in Wiring Systems. Did you find and correct the condition? | -- | Go to Step 30 | Go to Step 22 | ||||||||
22 | 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 30 | Go to Step 28 | ||||||||
23 | Inspect for poor connections at the harness connector of the PCM. 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 30 | Go to Step 29 | ||||||||
24 | Inspect for poor connections at the harness connector of the TAC module. 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 30 | Go to Step 27 | ||||||||
25 | 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 30 | -- | ||||||||
26 | Repair the open or the high resistance in the stop lamp switch signal circuit between the underhood fuse block and the TAC module. Refer to Wiring Repairs in Wiring Systems. Did you complete the repair? | -- | Go to Step 30 | -- | ||||||||
27 | Replace the TAC module. Refer to Control Module References in Computer/Integrating Systems for replacement, setup, and programming. Did you complete the replacement? | -- | Go to Step 30 | -- | ||||||||
28 | 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 30 | -- | ||||||||
29 | 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 30 | -- | ||||||||
30 |
Does the cruise control system operate properly? | -- | System OK | Go to Step 2 | ||||||||
Cruise Control Inoperative/Malfunctioning 3.6L
Diagnostic Aids
Caution: Refer to SIR Caution in the Preface section.
Disable the inflatable restraint steering wheel module when performing this diagnostic table. Refer to SIR Disabling and Enabling in SIR.
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 |
| • | With a scan tool, observe the cruise control function switch parameters, in the powertrain control module (PCM) cruise control data list, while rotating the steering wheel to both steering stops and individually activating each cruise control function switch separately. This will help eliminate the possibility of an internally shorted inflatable restraint steering wheel module coil. |
| • | Inspect for proper operation of the stop lamps. Refer to Exterior Lighting Systems Description and Operation in Lighting Systems. |
| • | 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 Controls 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 | Is DTC P0573 current in the engine control module (ECM)? | -- | Go to DTC P0573 in Lighting Systems | Go to Step 3 | ||||||||
3 |
Does the Cruise On/Off Switch parameter display Off? | -- | Go to Step 4 | Go to Step 7 | ||||||||
4 |
Does the Cruise On/Off Switch parameter display On? | -- | Go to Step 5 | Go to Step 8 | ||||||||
5 |
Does the Cruise Set/Coast Switch parameter display On? | -- | Go to Step 6 | Go to Step 9 | ||||||||
6 |
Does the Cruise Resume/Accel. Switch parameter display On? | -- | Go to Diagnostic Aids | Go to Step 9 | ||||||||
7 |
Does the Cruise On/Off Switch parameter display Off? | -- | Go to Step 14 | Go to Step 11 | ||||||||
8 |
Does the test lamp illuminate? | -- | Go to Step 10 | Go to Step 20 | ||||||||
9 |
Important: The cruise control on/off switch must be turned ON in order to correctly view the set/coast and the resume/accel switch resistance values with the DMM.
Do the cruise control function switch resistance values measure between the specified values? | Off = O.L. On = 7.8 K ohms-8.6 K ohms Resume = 2.7 K ohms-3.0 K ohms Set = 1.2 K ohms-1.3 K ohms | Go to Step 12 | Go to Step 18 | ||||||||
10 |
Important: The cruise control on/off switch must be turned ON in order to correctly view the set/coast and the resume/accel switch resistance values with the DMM.
Do the cruise control function switch resistance values measure between the specified values? | Off = O.L. On = 7.8 K ohms-8.6 K ohms Resume = 2.7 K ohms-3.0 K ohms Set = 1.2 K ohms-1.3 K ohms | Go to Step 12 | Go to Step 13 | ||||||||
11 | Test the cruise control set/coast and resume/accelerate 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 23 | Go to Step 19 | ||||||||
12 | Test the cruise control set/coast and resume/accelerate switch signal circuit for the following:
Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition? | -- | Go to Step 23 | Go to Step 19 | ||||||||
13 | Test the ignition 1 voltage circuit for the following, between C277 and the cruise control switch assembly.
Refer to Wiring Repairs in Wiring Systems. Did you find and correct the condition? | -- | Go to Step 23 | Go to Step 16 | ||||||||
14 | Test the cruise control on switch signal circuit for a short to voltage. Refer to Wiring Repairs in Wiring Systems. Did you find and correct the condition? | -- | Go to Step 23 | Go to Step 15 | ||||||||
15 | Test the cruise control set/coast and resume/accelerate switch signal circuit for a short to voltage between C277 and the cruise control switch assembly. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition? | -- | Go to Step 23 | Go to Step 18 | ||||||||
16 | Test the cruise control set/coast and resume/accelerate switch signal circuit for the following, between C277 and the cruise control switch assembly.
Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition? | -- | Go to Step 23 | Go to Step 17 | ||||||||
17 | Test the cruise control on switch signal circuit for the following:
Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition? | -- | Go to Step 23 | Go to Step 18 | ||||||||
18 | 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 23 | Go to Step 21 | ||||||||
19 | Inspect for poor connections at the harness connector of the engine control module (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 23 | Go to Step 22 | ||||||||
20 | Repair the following in the ignition 1 voltage circuit.
Refer to Wiring Repairs in Wiring Systems. Did you complete the repair? | -- | Go to Step 23 | -- | ||||||||
21 | 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 23 | -- | ||||||||
22 | 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 23 | -- | ||||||||
23 |
Does the Cruise Control System operate properly? | -- | System OK | Go to Step 2 | ||||||||
