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. |
| • | Inspect for proper adjustment of the cruise release switch. Refer to Cruise Release Switch Adjustment . |
| • | Inspect for proper adjustment of the clutch release switch. Refer to Clutch Pedal Cruise Control Release Switch Adjustment . |
| • | Inspect for proper operation of the clutch pedal. |
| • | 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: Master Electrical Component List in Wiring Systems | ||||||||||
1 | Did you perform the Cruise Control Diagnostic System Check? | -- | Go to Step 2 | |||||||
2 |
Do all of the parameters listed above display Off? | -- | Go to Step 3 | Go to Step 13 | ||||||
3 |
Does the Cruise on/off Switch parameter display On? | -- | Go to Step 4 | Go to Step 11 | ||||||
4 |
Does the Cruise Set/Coast Switch parameter display On? | -- | Go to Step 5 | Go to Step 12 | ||||||
5 |
Does the Cruise Resume/Accel Switch parameter display On? | -- | Go to Step 6 | Go to Step 12 | ||||||
6 | Do the stop lamps operate properly? | -- | Go to Step 7 | Go to Stop Lamps Inoperative or to Stop Lamps Always On in Lighting Systems | ||||||
7 | Test the stop lamp supply voltage 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 25 | Go to Step 8 | ||||||
8 | Is the vehicle equipped with a manual transmission? | -- | Go to Step 9 | Go to Step 20 | ||||||
9 |
Does the resistance measure between the specified values? | 10-15 ohms | Go to Step 10 | Go to Step 18 | ||||||
10 |
Does the resistance measure at approximately the specified value? | O.L. | Go to Step 14 | Go to Step 18 | ||||||
11 | Connect a DMM between the ignition 1 voltage circuit at the back of C204 and a good ground. Does the voltage measure at the specified value? | B+ | Go to Step 12 | Go to Step 21 | ||||||
12 |
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 17 | Go to Step 19 | ||||||
13 |
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 resistance values measure at 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 19 | ||||||
14 |
Does the test lamp illuminate? | -- | Go to Step 15 | Go to Step 21 | ||||||
15 | Test the clutch 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 25 | Go to Step 20 | ||||||
16 | 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 25 | Go to Step 20 | ||||||
17 | Test the cruise control set/coast and resume/accelerate switch signal circuit for an open, 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 25 | Go to Step 20 | ||||||
18 | Inspect for poor connections at the harness connector of the clutch 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 25 | Go to Step 22 | ||||||
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 25 | 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 25 | Go to Step 24 | ||||||
21 | 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 25 | -- | ||||||
22 | Replace the clutch release switch. Refer to Clutch Pedal Cruise Control Release Switch Replacement . Did you complete the replacement? | -- | Go to Step 25 | -- | ||||||
23 | 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 25 | -- | ||||||
24 |
Important: Program the replacement powertrain control module (PCM). Replace the PCM. Refer to Powertrain Control Module Replacement in Engine Controls - 2.8L (LK5) or to Powertrain Control Module Replacement in Engine Controls - 3.5L (L52). Did you complete the replacement? | -- | Go to Step 25 | -- | ||||||
25 | Operate the vehicle with in the conditions for cruise control operation. Does the cruise control system operate properly? | -- | System OK | Go to Step 2 | ||||||
