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 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 Wiring Systems. |
| • | 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. |
| • | For an intermittent condition, refer to Testing for Intermittent Conditions and Poor Connections in Wiring Systems. |
Test Description
The number below refers to the step number on the diagnostic path.
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This step tests the vehicle speed signal circuit for a short to ground, for a short to voltage, for an open, or for a high resistance between the PCM and the TAC module.
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This step tests the ignition 1 voltage circuit for a short to ground, for an open, or for a high resistance.
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This step tests the cruise control set/coast and resume/accelerate switch signal circuit for a short to voltage.
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This step tests the cruise control set/coast and resume/accelerate switch signal circuit for a short to ground, for a short to voltage, for an open, or for a high resistance.
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DTCs will set in the powertrain control module (PCM) when you perform this diagnostic table.
Step | Action | Values | Yes | No | ||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
Schematic Reference: Cruise Control Schematics or Engine Controls Schematics Connector End View Reference: Master Electrical Component List in Wiring Systems | ||||||||||||
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 9 | Go to Step 3 | ||||||||
3 |
Does the Cruise On/Off Switch parameter display On? | -- | Go to Step 4 | Go to Step 8 | ||||||||
4 |
Does the Cruise Set/Coast Switch parameter display On? | -- | Go to Step 5 | Go to Step 10 | ||||||||
5 |
Does the Cruise Resume/Accel. Switch parameter display On? | -- | Go to Step 6 | Go to Step 10 | ||||||||
Does the voltage measure greater than the specified value? | 8.5 V | Go to Step 7 | Go to Step 11 | |||||||||
7 | 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 26 | Go to Step 21 | ||||||||
Does the test lamp illuminate? | -- | Go to Step 10 | Go to Step 22 | |||||||||
|
Important: The cruise control On/Off switch must be turned ON in order to correctly view the set/coast switch 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 12 | Go to Step 17 | |||||||||
|
Important: The cruise control On/Off switch must be turned ON in order to correctly view the set/coast switch 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 14 | |||||||||
11 | 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 26 | Go to Step 20 | ||||||||
12 | Test the cruise control set/coast and resume/accel switch signal circuit for a short to voltage between C277 and the powertrain control module (PCM). Refer to Circuit Testing and to Wiring Repairs in Wiring Systems. Did you find and correct the condition? | -- | Go to Step 26 | Go to Step 20 | ||||||||
13 | Test the cruise control set/coast and resume/accel 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 26 | Go to Step 20 | ||||||||
14 | Test the ignition 1 voltage circuit between C277 and the cruise control switch for the following:
Refer to Circuit Testing and to Wiring Repairs in Wiring Systems. Did you find and correct the condition? | -- | Go to Step 26 | Go to Step 15 | ||||||||
15 | 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 26 | Go to Step 16 | ||||||||
16 | Test the cruise control set/coast and resume/accelerate switch signal circuit between C277 and the cruise control switch for the following:
Refer to Circuit Testing and to Wiring Repairs in Wiring Systems. Did you find and correct the condition? | -- | Go to Step 26 | Go to Step 19 | ||||||||
17 | 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 26 | Go to Step 18 | ||||||||
18 | Test the cruise control set/coast and resume/accelerate switch signal circuit between C277 and the cruise control switch 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 26 | Go to Step 19 | ||||||||
19 | 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 26 | Go to Step 23 | ||||||||
20 | 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 26 | Go to Step 25 | ||||||||
21 | 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 26 | Go to Step 24 | ||||||||
22 | Repair the following in the ignition 1 voltage circuit:
Refer to Wiring Repairs in Wiring Systems. Did you complete the repair? | -- | Go to Step 26 | -- | ||||||||
23 | Replace the cruise control switch. Refer to Steering Wheel Control Switch Assembly Replacement . Did you complete the replacement? | -- | Go to Step 26 | -- | ||||||||
24 | 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 26 | -- | ||||||||
25 | 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 26 | -- | ||||||||
Does the Cruise Control System operate properly? | -- | System OK | Go to Step 2 | |||||||||
