Cruise Control Tester

It has been found that when this Tester is used on some vehicles with high resistance or an open in the cruise control module ground circuit, the Tester's LED(s) will light abnormally. For example, the Brake/Clutch and VSS LED(s) will light normally but the Ignition LED will be dim with the ON/OFF switch in the OFF position. However, with the ON/OFF switch in the ON position only the VSS LED will light. If you come upon the above situation, please check the ground circuit prior to going on with your diagnosis.

1. Perform CRUISE CONTROL DIAGNOSTIC SYSTEM CHECK . Once test has been performed, go to next step.
2. Connect the J 42958 cruise control tester between the harness connector of the cruise control module and the cruise control module. Place the cruise control On/Off switch in the off position. Turn on the ignition, with the engine off. If the ignition LED on the J 42958 illuminates, go to next step. If not, go to step  20.
3. If the brake/TCC LED on the J 42958 illuminates, go to next step. If not, go to step  22.
4. If the brake lights LED on the J 42958 is off, go to next step. If not, go to step  23.
5. Press and release the brake pedal. Press and release the cancel switch. If the brake/TCC LED turns off on the J 42958 when each step was performed, go to next step. If not, go to step  25.
6. Place the cruise control On/Off switch in the On position. Leave the switch On until instructed to turn it Off. If the On/Off and the Inhibit/Enable LED on the J 42958 illuminates, go to next step. If not, go to step  27.
7. If the cruise lamp LED on the J 42958 illuminates, go to next step. If not, go to step  28.
8. Press and release the Set/Coast switch. If the Set/Coast LED on the J 42958 illuminated when the Set/Coast switch was pressed, and turned off when the Set/Coast switch was released, go to next step. If not, go to step  30.
9. Press and release the Resume/Accel switch. If the Resume/Accel led on the J 42958 illuminated when the Resume/Accel switch was pressed, and turned off when the Resume/Accel switch was released, go to next step. If not, go to step  31.
10. Perform the following sequence: press and release the Inhibit Override button on the J 42958. Press and release the Brake button on the J 42958. Press and release the S/C Button on the J 42958. If the Cruise Engage LED illuminated continually after the S/C button was pressed and released, go to next step. If not, go to step  20.
11. Observe the throttle lever at the throttle body. Press and hold the R/A Button on the J 42958 for five seconds, and then release it. If the throttle moved to near wide open, and then returned approximately to half throttle when the R/A button on the J 42958 was released, go to next step. If not, go to step  36.
12. Observe the throttle lever at the throttle body. Press and hold the S/C button on the J 42958 For five seconds, and then release it. If the throttle moved toward closed throttle, and then returned to approximately half throttle when the S/C button on the J 42958 was released, go to next step. If not, go to step  36.
13. Press and release (tap) the R/A button on the J 42958 three times. Press and release the brake button on the J 42958. If the cruise engage LED on the J 42958 turned off and the throttle returned to the closed position, go to next step. If not, go to step  36.
14. Raise and support vehicle. Block one of the drive wheels. Turn on the ignition, with the engine off. Place The transaxle/transmission selector in Drive. Observe the VSS LED on the J 42958 while rotating the drive wheel that is not blocked, by hand. Place the transaxle/transmission selector in Park. If the VSS LED flashed while the one drive wheel was rotated, go to next step. If not, go to step  33.
15. If the connector harness of the cruise control module has a wire connected to terminal H, go to next step. If not, go to step  19.
16. Install scan tool. Turn on the ignition, with the engine off. Select Powertrain Special Functions and then Output Controls For Cruise Inhibit. While observing the inhibit enable LED of the J 42958, use the scan tool in order to enable the cruise control. If the inhibit enable LED on the J 42958 dimmed when the scan tool was used to enable cruise control, go to next step. If not, go to step  32.
17. Turn off the ignition. Disconnect the J 42958 and reconnect the vehicle harness to the cruise control module. Road test the vehicle over 25 MPH (40 KM/H). Operate the cruise control. Use the scan tool in order to view the cruise inhibit status. If the scan tool displays Enabled above 40 25 MPH (40 KM/H), go to next step. If not, see SELF-DIAGNOSTICS - 3.5L or SELF-DIAGNOSTICS - 4.0L article in ENGINE PERFORMANCE.
18. If the cruise control set and operated normally, see Diagnostic Aids . If not, go to step  36.
19. Reconnect all components. Road test vehicle and operate cruise control. If cruise control operates normally, see Diagnostic Aids . If not, go to step  36.
20. Test for an open, high resistance or short to ground in the ignition voltage circuit of the cruise control module. If you found and corrected the condition, go to step  39. If not, go to next step.
21. Repair the high resistance or the open in the ground circuit of the cruise control module. If you found and corrected the condition, go to step  39. If not, go to step  36.
22. Inspect the cruise control release switch for proper adjustment. See CRUISE RELEASE SWITCH  under REMOVAL & INSTALLATION. If you found and corrected the condition, go to step  39. If not, go to step  24.
23. Inspect the brakelight switch for proper adjustment. If you found and corrected the condition, go to step  39. If not, go to step  26.
24. Repair the open or the short to ground in the cruise control cancel signal circuit of the cruise control module. If you found and corrected the condition, go to step  39. If not, go to step  34.
25. Repair the short to voltage in the cruise control cancel signal input circuit of the cruise control module. If you found and corrected the condition, go to step  39. If not, go to step  34.
26. Repair the open or high resistance in the brakelight switch signal circuit of the cruise control module. If you found and corrected the condition, go to step  39. If not, go to step  35.
27. Repair the open or the short to ground in the cruise control on switch signal circuit of the cruise control module. If you found and corrected the condition, go to step  39. If not, go to step  37.
28. Disconnect the J 42958 from the cruise control module, but leave the vehicle harness connected to the J 42958. If the cruise lamp LED remained off when the cruise control module was connected, go to next step. If not, go to step  36.
29. Test for an open or short to ground in the cruise engaged output circuit. If you found and corrected the condition, go to step  39. If not, go to step  37.
30. Test for an open or short to ground in the cruise control Set/Coast switch signal circuit. If you found and corrected the condition, go to step  39. If not, go to step  37.
31. Test for an open or short to voltage in the cruise control resume/accel switch signal circuit. If you found and corrected the condition, go to step  39. If not, go to step  37.
32. Test for an open or high resistance in the cruise control inhibit signal circuit between the cruise control module and the PCM. If you found and corrected the condition, go to step  39. If not, go to step  38.
33. Test for an open or high resistance in the vehicle speed signal circuit between the cruise control module and the PCM. If you found and corrected the condition, go to step  39. If not, go to step  36.
34. Replace the cruise release switch. Once you complete the replacement, go to step  39.
35. Replace brakelight switch. Once you complete the replacement, go to step  39.
36. Replace the cruise control module. Once you complete the replacement, go to step  39.
37. Replace the cruise control switch. Once you complete the replacement, go to step  39.
38. Replace the PCM. See REMOVAL, OVERHAUL & INSTALLATION article in ENGINE PERFORMANCE. Program the PCM. See POWERTRAIN CONTROL MODULE  under PROGRAMMING. Once you complete the replacement, go to next step.
39. Operate the vehicle within the conditions for cruise control operation. If the cruise control system does not operate correctly, go to step  2.