Circuit Description
The Cruise control multi function lever is wired directly to the PCM. The cruise ON/OFF, set/coast and resume/accel signals are inputs to the fuel control portion of the PCM. These inputs allow the PCM to control and hold a requested speed. The cruise can be disengaged at anytime time by applying the brakes. This input is sent to the PCM by the Cruise Control Brake Switch.
Diagnostic Aids
If the cruise is inoperative and no cruise control or brake switch DTCs are stored, check for the following conditions:
| • | A malfunctioning cruise multi-function switch or wiring harness, including opens or poor connections |
| • | A clutch pedal switch stuck in the open position |
Other conditions that will not allow the cruise control to engage that are not the fault of the cruise system.
| • | Vehicle speed below 40 km/h (25 mph)--If cruise is already set, cruise will disengage at 32 km/h (20 mph). |
| • | Vehicle in 4 wheel drive low. |
| • | Any DTC that puts vehicle in back-up fuel mode. Back-up fuel mode affects the fuel control portion of the PCM. Refer to the appropriate DTC. |
| • | More than one accelerator pedal position (APP) DTC set |
Test Description
The numbers below refer to the step numbers on the diagnostic table:
Step | Action | Values | Yes | No |
|---|---|---|---|---|
1 |
Important: Before clearing the DTCs, use the scan tool Capture Info to save the Freeze Frame and Failure Records for reference. The data in the control module is deleted once the Clear Info function is used. Did you perform the Powertrain On-Board Diagnostic (OBD) System Check? | -- | ||
2 | Are any Engine or Transmission DTCs set? | -- | Go to the applicable DTC table | |
Is the test light ON? | -- | |||
4 |
Does the scan tool indicate the cruise switch is turning ON and OFF? | -- | ||
5 |
Does the scan tool indicate the set switch is turning ON and OFF? | -- | ||
6 |
Does the scan tool indicate the resume switch is turning ON and OFF? | -- | ||
7 |
Does the test light turn ON and OFF with each cruise control ON/OFF switch cycle? | -- | ||
8 |
Does the test light turn ON and OFF with each cruise control ON/OFF switch cycle? | -- | ||
9 |
Does the test light turn ON and OFF with each cruise control set/coast switch cycle? | -- | ||
10 |
Does the test light turn ON and OFF with each cruise control set/coast switch cycle? | -- | ||
11 |
Does the test light turn ON and OFF with each cruise control resume/accelerate switch cycle? | -- | ||
12 |
Does the test light turn ON and OFF with each cruise control resume/accelerate switch cycle? | -- | ||
13 | Check for and repair the open in the ignition feed circuit. Did you perform a repair? | -- | ||
14 | Check for and repair the open or short to ground in the cruise ON/OFF request signal circuit. Did you perform a repair? | -- | ||
15 | Check for and repair the open or short to ground in the cruise set/coast request signal circuit. Did you perform a repair? | -- | ||
16 | Check for and repair the open or short to ground in the cruise Resume/Accelerate request signal circuit. Did you perform a repair? | -- | ||
17 |
Did you perform a repair? | -- | ||
18 | Replace the cruise control switch . Is the action complete? | -- | -- | |
19 |
Did you perform a repair? | -- | ||
20 |
Important: The new PCM must be programmed. Replace the PCM. Refer to Powertrain Control Module Replacement/Programming . Is the action complete? | -- | -- | |
21 | Operate the vehicle within the conditions under which the original problem was noted. Does the system operate properly? | -- | System OK |
