Cruise Control System Cadillac DeVille Concours I final

DESCRIPTION & OPERATION

Cruise control is a speed control system that maintains a desired vehicle speed under normal driving conditions. Steep grades may cause variations in selected speeds. System has capability to cruise, coast, resume speed, accelerate, tap-up and tap-down.

The main components of the cruise control system include the cruise control module, cruise control functional switches, Vehicle Speed Sensor (VSS), cruise control release and brake switches and ABS/TCC switch. See COMPONENT LOCATIONS .

CRUISE CONTROL FUNCTIONAL SWITCHES

Note. Multifunction lever may also be referred to as combination switch or multifunction switch.

Cruise control functional switches are located on the end of multifunction lever, which also serves as a turn signal lever. Functional switches include a SET switch and a sliding main switch with OFF, ON and RESUME/ACCEL positions. Switch functions are described as follows

1. OFF System disengages when cruise control switch is turned off.
2. ON System is ready to be set when cruise control switch is turned on.
3. RESUME/ACCEL (R/A) Spring-loaded R/A switch will not initially set cruise speed, but when cruise has been disengaged by braking, momentarily sliding this switch to R/A position will cause cruise to resume previously set speed. This is the resume function. Accelerate function occurs when R/A switch is held in position for more than one second. This causes the vehicle to accelerate until switch is released. When released, system maintains new set speed. Also, by quickly pressing and releasing (tapping) this switch, the set speed is "tapped-up" in one MPH increments.
4. SET (Set/Coast) Spring-loaded SET switch engages cruise. During engagement, if SET button is pressed and held, vehicle decelerates (cruise disengages) until switch is released. When switch is released, cruise engages and maintains new set speed. Also, by quickly pressing and releasing (tapping) this button, the set speed is "tapped-down" in one MPH increments.

CRUISE CONTROL MODULE

The cruise control module contains an electronic controller and electric stepper motor. Controller monitors vehicle speed and operates electric stepper motor. Responding to controller, stepper motor moves a connecting strap that is attached to cruise control cable. Cable moves throttle linkage to vary throttle position in order to maintain desired cruise speed. Cruise control module contains a low speed limit function which will prevent system engagement when vehicle speeds are less than about 25 MPH.

CRUISE CONTROL RELEASE SWITCH, BRAKE SWITCH & ABS/TCC SWITCH

Cruise control release, brake and ABS/TCC switches disengage cruise control operation electrically when brake pedal is depressed. Cruise control release and brake switch is closed when brake pedal is pressed. ABS/TCC switch is open when brake pedal is pressed. This is done by activating the brake cut-out input electrical circuit to cruise control module. Vehicle speed at brake actuation will be stored in system memory.

VEHICLE SPEED SENSOR (VSS)

The VSS is mounted on transaxle case extension housing. VSS produces an AC signal with a frequency proportional to speed at which transaxle assembly output shaft rotates, which is also proportional to vehicle speed. The AC signal is sent to cruise control module and speedometer by Powertrain Control Module (PCM). The signal is sent at a rate of 4000 pulses per mile, and the PCM converts number of pulses per mile to pulses per second to determine speed of vehicle. The signal is sent to cruise control module and instrument panel module.

COMPONENT LOCATIONS

COMPONENT LOCATIONS

ABS/TCC SWITCH

Brake booster pushrod must be assembled to brake pedal before ABS/TCC switch can be adjusted. DO NOT press brake pedal during adjustment procedure. Insert switch into retainers until fully seated against brake pedal bracket. Turn switch clockwise about 60 degrees until travel stop is reached. When switch is fully locked, electrical connector should face 3 o'clock position. Ensure clearance between switch barrel and brake pedal is 1/16" (1.5-1.7 mm). Switch contacts should be closed with brake pedal released. Measure pedal travel from centerline of brake pedal and ensure switch contacts are open at 1/8-1/2" (3.5-12.5 mm) of pedal travel.

CRUISE CONTROL CABLE

Disengage, but DO NOT remove adjustment lock on throttle end of cruise control cable. Cable should move freely in and out of adjuster. Hold throttle at closed position. Pull on cable conduit to take up slack in cable. Engage adjustment lock.

CRUISE CONTROL RELEASE SWITCH & BRAKE SWITCH

1. Brake booster pushrod must be assembled to brake pedal before cruise control release and brake switch can be adjusted. DO NOT press brake pedal during adjustment procedure. Insert switch into retainers until fully seated against brake pedal bracket. Turn switch clockwise about 60 degrees until travel stop is reached. When switch is fully locked, electrical connector should face 3 o'clock position. Ensure clearance between switch barrel and brake pedal is 1/16" (1.5-1.7 mm).
2. Check brakelights for proper operation. Switch contacts should be open with brake pedal released. Measuring pedal travel from centerline of brake pedal, ensure switch contacts are closed at 1/8-1/2" (3.5-12.5 mm) of pedal travel.

PRELIMINARY INSPECTION

1. PCM will disable cruise control if any of the following conditions are detected: Engine is off. Transaxle is in Park, Neutral, Low or Reverse. Engine speed is too high. Vehicle speed is too high. Vehicle acceleration or deceleration rate is too high. ABS/traction control system is active for more than 2 seconds. Diagnostic Trouble Codes (DTCs) are set.
2. Check fuses, and replace as necessary. Visually inspect for broken or open wires. Check for a broken or partially broken wire inside insulation which could cause system malfunction but prove good in a continuity/voltage check with system disconnected.
3. Check for PCM DTCs. If any PCM DTCs are present, diagnose engine control system as necessary. See appropriate SELF-DIAGNOSTICS article in ENGINE PERFORMANCE.
4. Ensure cruise control module linkage is connected and moves freely without binding. Check cruise control cable adjustment. See «CRUISE CONTROL CABLE»(/cadillac/deville-concours/i-final-1999-1999/remont/cruise-control-systems/#cruise-control-system__cruise-control-cable) under ADJUSTMENTS. Ensure both brake pedal switches are installed correctly. See «ABS/TCC SWITCH»(/cadillac/deville-concours/i-final-1999-1999/remont/cruise-control-systems/#cruise-control-system__abstcc-switch) and «CRUISE CONTROL RELEASE SWITCH & BRAKE SWITCH»(/cadillac/deville-concours/i-final-1999-1999/remont/cruise-control-systems/#cruise-control-system__cruise-control-release-switch-brake) under ADJUSTMENTS. Ensure center high-mounted brakelight is operating.
5. Ensure any aftermarket electronic equipment is properly installed. Repair as necessary. If no problems are found, go to «DIAGNOSTIC CHECK»(/cadillac/deville-concours/i-final-1999-1999/remont/cruise-control-systems/#cruise-control-system__diagnostic-check) .

DIAGNOSTIC CHECK

Note. Diagnostic check determines if PCM is capable of controlling cruise control module. If diagnostic check fails, PCM, cruise control module or linkage may be at fault.

1. Using scan tool, command PCM to enable cruise control system. Set parking brake and start engine. Place cruise control switch in OFF position, and then in ON position. Wait 3 minutes. After 3 minutes, depress and hold SET switch. Hold slider switch in R/A position. Fully depress and hold brake pedal and wait 10 seconds.
2. After 10 seconds, release brake pedal while holding R/A and SET switches. Engine RPM should increase momentarily, and then return to idle. Clear any DTCs which may be set. Go to «SYSTEM CHECK»(/cadillac/deville-concours/i-final-1999-1999/remont/cruise-control-systems/#cruise-control-system__system-check) .

SYSTEM CHECK

1. Drive vehicle at a speeds greater than 25 MPH. Place cruise control main switch in ON position. Press SET switch once and release. Remove foot from accelerator pedal. Vehicle should maintain set speed. If vehicle maintains speed, go to next step. If vehicle does not maintain set speed, go to «CRUISE CONTROL INOPERATIVE»(/cadillac/deville-concours/i-final-1999-1999/remont/cruise-control-systems/#cruise-control-system__cruise-control-inoperative) under SYSTEM TESTS.
2. Hold slider switch in R/A position until vehicle speed increases 4-5 MPH. Vehicle should accelerate and maintain new set speed. Press SET switch until vehicle speed decreases 4-5 MPH. Vehicle should decelerate and maintain new set speed. If system operates as specified, go to next step. If system does not operate as specified, go to «CRUISE CONTROL WILL NOT RESUME, ACCELERATE OR TAP-UP»(/cadillac/deville-concours/i-final-1999-1999/remont/cruise-control-systems/#cruise-control-system__cruise-control-will-not-resume-accelerate) under SYSTEM TESTS.
3. Depress brake pedal slightly. Cruise control system should disengage. If system does not disengage, go to «CRUISE CONTROL INOPERATIVE»(/cadillac/deville-concours/i-final-1999-1999/remont/cruise-control-systems/#cruise-control-system__cruise-control-inoperative) under SYSTEM TESTS. Press slider switch in R/A position once and release. Vehicle should accelerate and maintain previously set speed. Tap-up R/A switch (less than 3/4 of a second). Vehicle speed should increase by one MPH. Tap-down SET button (less than 3/8 of a second). Vehicle speed should decrease by one MPH. If system operates as specified, go to next step. If system does not operate as specified, go to «CRUISE CONTROL WILL NOT RESUME, ACCELERATE OR TAP-UP»(/cadillac/deville-concours/i-final-1999-1999/remont/cruise-control-systems/#cruise-control-system__cruise-control-will-not-resume-accelerate) under SYSTEM TESTS.
4. Simultaneously press SET and R/A switches. Cruise control system should disengage, but retain previously set speed in memory. Place main switch in OFF position. Cruise control system should disengage, and set speed should be erased from memory. If system does not operate as specified, go to «CRUISE CONTROL INOPERATIVE»(/cadillac/deville-concours/i-final-1999-1999/remont/cruise-control-systems/#cruise-control-system__cruise-control-inoperative) under SYSTEM TESTS.

SYSTEM TESTS

Note. The following tests are written specifically for General Motor's Tech 1 scan tool. A generic scan tool may not be capable of performing all necessary test functions.

Note. For wire terminal, color and circuit identification, see WIRING DIAGRAMS . To aid in component location, see COMPONENT LOCATIONS .

CRUISE CONTROL INOPERATIVE

Note. To avoid misdiagnosis, ensure preliminary inspection and all checks have been performed. See TROUBLE SHOOTING .

1. Turn cruise control switch to OFF position. Disconnect cruise control module harness connector. Turn ignition on. Measure voltage between cruise control module harness connector (harness side) terminal "F" (Pink wire) and ground. Voltage should be 10-15 volts. If voltage is not as specified, go to next step. If voltage is as specified, go to step 3 .
2. Repair open in Pink wire between cruise control module and engine compartment fuse/relay center. After repairs, go to step 30 .
3. Measure voltage between cruise control module harness connector (harness side) terminals "F" (Pink wire) and "E" (Black/White wire). Voltage should be 10-15 volts. If voltage is not as specified, go to next step. If voltage is as specified, go to step 5 .
4. Repair open in Black/White wire between cruise control module and ground. After repairs, go to step 30 .
5. Measure voltage between ground and 48-pin harness connector C202, terminal E1 (Pink wire) located at base of steering column. Voltage should be 10-15 volts. If voltage is not as specified, go to next step. If voltage is as specified, go to step 7 .
6. Repair open in Pink wire between rear compartment fuse block and ABS/TCC switch. After repairs, go to step 30 .
7. Turn cruise control switch to ON position. Measure voltage between ground and 48-pin harness connector C202, terminal E2 (Gray wire) located at base of steering column. Voltage should be 10-15 volts. If voltage is not as specified, go to next step. If voltage is as specified, go to step 9 .
8. Check for poor cruise control switch connections. Clean or repair as necessary. If no problem is found, replace multifunction lever. See appropriate STEERING COLUMN SWITCHES article. After repairs, go to step 30 .
9. Measure voltage between cruise control module harness connector terminal "A" (Gray wire) and ground. Voltage should be 10-15 volts. If voltage is not as specified, go to next step. If voltage is as specified, go to step 11 .
10. Repair open or short to ground in Gray wire between cruise control module and multifunction lever. After repairs, go to step 30 .
11. Measure voltage between ground and 48-pin harness connector C202, terminal E3 (Dark Blue wire) located at base of steering column. Voltage should be 10-15 volts. If voltage is as specified, go to next step. If voltage is not as specified, go to step 8 .
12. Measure voltage between cruise control module harness connector terminal "B" (Dark Blue wire) and ground. Voltage should be 10-15 volts. If voltage is not as specified, go to next step. If voltage is as specified, go to step 14 .
13. Repair open or short to ground in Dark Blue wire between cruise control module and multifunction lever. After repairs, go to step 30 .
14. Measure voltage between cruise control module harness connector terminal "G" (Light Blue wire) and ground. Voltage should be less than .5 volt. If voltage is not as specified, go to next step. If voltage is as specified, go to step 16 .
15. Repair short to battery voltage in Light Blue wire. After repairs, go to step 30 .
16. Measure voltage between cruise control module harness connector terminal "D" (Purple wire) and ground. Press brake pedal, and then release. Voltage should be less than .5 volt with pedal depressed, and 10-15 volts with pedal released. If voltage is not as specified, go to next step. If voltage is as specified, go to step 22 .
17. Turn ignition off. Disconnect ABS/TCC switch harness connector. Turn ignition on. Measure voltage between cruise control module harness connector terminal "A" (Gray wire) and ground. Voltage should be 10-15 volts. If voltage is not as specified, go to next step. If voltage is as specified, go to step 19 .
18. Repair open or short in Pink wire between rear compartment fuse block and ABS/TCC switch. After repairs, go to step 30 .
19. Turn ignition off. Connect a fused jumper wire between ABS/TCC switch harness connector terminals "A" (Pink wire) and "B" (Purple wire). Turn ignition on. Measure voltage between cruise control module harness connector terminal "D" (Purple wire) and ground. Voltage should be 10-15 volts. Remove jumper wire. Voltage should be less than .5 volt. If voltage is not as specified, go to next step. If voltage is as specified, go to step 21 .
20. Repair open or short in Purple wire between cruise control module and ABS/TCC switch. After repairs, go to step 30 .
21. Check ABS/TCC switch harness connections. Repair as necessary. After repairs, go to step 30 .
22. Raise and support vehicle with drive wheels off ground. Measure voltage between cruise control module harness connector terminal "K" (Dark Green wire) and ground. Rotate drive wheels. If voltage does not vary, go to next step. If voltage varies, go to step 24 .
23. Repair open or short in Dark Green/White wire between cruise control module and PCM. After repairs, go to step 30 .
24. Turn ignition off. Reconnect cruise control module harness connector. Disconnect PCM harness connector C1. Turn ignition on. Measure voltage between PCM harness connector C1, terminal No. 26 (Dark Green wire) and ground. If 10-15 volts does not exist, go to next step. If 10-15 volts exists, go to step 27 .
25. Check for an open or short to ground in Dark Green wire between cruise control module and PCM. If Dark Green wire is open or shorted, go to next step. If Dark Green wire is okay, go to step 28 .
26. Repair open or short in Dark Green wire between cruise control module and PCM. After repairs, go to step 30 .
27. Turn ignition off. Reconnect PCM harness connector C1. Disconnect cruise control module harness connector. Turn ignition on. Using scan tool, clear DTCs. Select PCM, SPECIAL FUNCTIONS, and then ENGINE OUTPUT CONTROLS. Select CRUISE INHIBIT and command PCM to turn cruise inhibit off. Measure voltage between cruise control module harness connector terminal "H" (Dark Green wire) and ground. Voltage should be 10-15 volts with cruise inhibit off (NO) and less than .5 volt with cruise inhibit on (YES). If voltage is not as specified, go to next step. If voltage is as specified, go to step 29 .
28. Ensure cruise control module harness connector is clean and tight. If connector is okay, replace cruise control module. See «CRUISE CONTROL MODULE»(/cadillac/deville-concours/i-final-1999-1999/remont/cruise-control-systems/#cruise-control-system) under REMOVAL & INSTALLATION. After repairs, go to step 30 .
29. Check PCM. See appropriate SELF-DIAGNOSTICS article in ENGINE PERFORMANCE. Repair as necessary. After repairs, go to next step.
30. Ensure all components are installed and connected. Recheck system. See «SYSTEM CHECK»(/cadillac/deville-concours/i-final-1999-1999/remont/cruise-control-systems/#cruise-control-system__system-check) under TROUBLE SHOOTING.

CRUISE CONTROL WILL NOT RESUME, ACCELERATE OR TAP-UP

Note. To avoid misdiagnosis, ensure preliminary inspection and all checks have been performed. See TROUBLE SHOOTING .

1. Turn ignition off. Disconnect cruise control module harness connector. Turn ignition on. Turn cruise control switch to ON position. Measure voltage (backprobe) between ground and 48-pin harness connector C202, terminal E4 (Gray/Black wire) located at base of steering column. Press and hold cruise control switch in R/A position. If 10-15 volts does not exist, go to next step. If 10-15 volts exists, go to step 3 .
2. Check for a poor connections at 48-pin harness connector C202 and multifunction lever. If no problem is found, replace multifunction lever. See appropriate STEERING COLUMN SWITCHES article. After repairs, go to step 6 .
3. Measure voltage between cruise control module harness connector terminal "C" (Gray/Black wire) and ground. Press and hold R/A switch. If 10-15 volts does not exist, go to next step. If 10-15 volts exists, go to step 5 .
4. Repair open or short to ground in Gray/Black wire. After repairs, go to step 6 .
5. Check for poor connections at cruise control module. Repair as necessary. If no problem is found, replace cruise control module. See «CRUISE CONTROL MODULE»(/cadillac/deville-concours/i-final-1999-1999/remont/cruise-control-systems/#cruise-control-system) under REMOVAL & INSTALLATION. After repairs, go to step 6 .
6. Reconnect all connectors. Recheck system. See «SYSTEM CHECK»(/cadillac/deville-concours/i-final-1999-1999/remont/cruise-control-systems/#cruise-control-system__system-check) under TROUBLE SHOOTING.

REMOVAL & INSTALLATION

Scheme 1

1. Disconnect negative battery cable. Remove cruise control release and brake switch. See «CRUISE CONTROL RELEASE SWITCH & BRAKE SWITCH»(/cadillac/deville-concours/i-final-1999-1999/remont/cruise-control-systems/#cruise-control-system). Turn switch counterclockwise to unlock, and pull switch from retainer. Disconnect electrical connectors. (Scheme 1)
2. To install, reconnect electrical connectors. Slide switch into retainer, and press until switch plunger is fully depressed into switch barrel. Turn switch clockwise about 60 degrees until travel stop is reached. When switch is fully locked, electrical connector should face 3 o'clock position. Install cruise control release and brake switch.

Note. Note cable routing prior to removal.

Disconnect cruise control cable at throttle body cam and throttle body bracket. Disconnect cable from cruise control module. To install, reverse removal procedure. Adjust cruise control cable. See CRUISE CONTROL CABLE under ADJUSTMENTS.

Note. Cruise control functional switches are located on the end of multifunction lever, which also serves as a turn signal lever. Switches are not serviceable and must be replaced with multifunction lever as an assembly. See appropriate STEERING COLUMN SWITCHES article.

Disconnect negative battery cable. Remove cruise control cable. See CRUISE CONTROL CABLE . Disconnect cruise control module harness connector. Remove cruise control module. Remove cruise control module from mounting bracket. To install, reverse removal procedure. Adjust cruise control cable. See CRUISE CONTROL CABLE under ADJUSTMENTS.

1. Disconnect negative battery cable. Remove left-side instrument panel sound insulator. Turn switch counterclockwise to unlock, and pull switch from retainer. Disconnect electrical connectors. (Scheme 1)
2. To install, reconnect electrical connectors. Slide switch into retainer, and press until switch plunger is fully depressed into switch barrel. Turn switch clockwise about 60 degrees until travel stop is reached. When switch is fully locked, electrical connector should face 3 o'clock position.

Disconnect negative battery cable. Raise and support vehicle. Disconnect VSS harness connector. Remove VSS mounting bolt. Remove VSS from transaxle case extension housing. To install, reverse removal procedure. Tighten bolt to 89 INCH lbs. (10 N.m).

See also:
• COMPONENT LOCATIONS
• CRUISE CONTROL CABLE
• ABS/TCC SWITCH
• CRUISE CONTROL RELEASE SWITCH & BRAKE SWITCH
• DIAGNOSTIC CHECK
• SYSTEM CHECK
• CRUISE CONTROL INOPERATIVE
• CRUISE CONTROL WILL NOT RESUME, ACCELERATE OR TAP-UP
• WIRING DIAGRAMS