1996 Audi A4 Cruise control

Tiny
PICKS
  • MEMBER
  • 1996 AUDI A4
  • 6 CYL
  • AWD
  • MANUAL
  • 128,000 MILES
The cruise control does not function, I checked all fuses and none were bad. I recently purchased this car so I don't know history of the cruise control. No lights appear on the dash when I turn the control on or try to engage it. Is there a common problem(s) with these units that I should investigate first?
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Friday, September 24th, 2010 AT 11:30 AM

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Tiny
MERLIN2021
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ARTICLE BEGINNING DESCRIPTION & OPERATION The cruise control system allows driver to maintain a constant cruising speed above 22 MPH without depressing the accelerator pedal. The cruise control system is operated by placing RESUME/ON/OFF switch in the ON position. Accelerate to desired speed and press the SET button. This sets the cruising speed and stores it in memory. Pushing the SET button again will increase the previous set speed until the button is released. Cruise control system will disengage temporarily when the brake or clutch pedal is depressed. To reactivate system, slide the RESUME/ON/OFF button to RESUME. The vehicle will automatically accelerate to the previous set speed. To erase set speed from memory, slide the RESUME/ON/OFF button to OFF. ADJUSTMENTS BRAKE & CLUTCH VENT VALVE SWITCHES Pull back associated pedal to its stop (as far as it will go). Adjust switch by slowly releasing pedal. Threads on vent valve will be damaged if vent valve is completely removed from bushing. Vent valve cannot be reused if threads are damaged. VACUUM SERVO LINKAGE ADJUSTMENT On vehicles with adjustable vacuum servo linkage, ensure throttle is closed. Turn adjuster nut on vacuum servo linkage until there is .004-.012" (0.1-0.3 mm) clearance between bushing and linkage. SYSTEM TESTS SYSTEM CHECK Check fuses. See WIRING DIAGRAM . Ensure brakelight operation is correct. Disconnect vacuum pump hose. Press in on actuator diaphragm. Plug vacuum pump hose. Actuator diaphragm should remain in place. Repair or replace components as necessary. CIRCUIT CHECKS WARNING: DO NOT shift into Neutral when cruise control system is switched on. The engine will rev up immediately and may possibly be damaged. Control Switch/Control Unit Check 1. Disconnect Cruise Control Unit (CCU) wiring harness connector. Connect voltmeter leads to terminals No. 5 and 8. See Fig. 1 . Turn control switch to ON position. Drive vehicle 20 MPH. If 12 volts are present, go to next step. If no voltage is present, replace control switch or repair open circuit. 2. Turn ignition off. Connect ohmmeter leads to terminals No. 8 and 10. Turn control switch to RESUME position. If resistance is zero ohms, go to next step. If resistance is infinite ohms, replace control switch or repair open circuit. 3. With ignition off, connect ohmmeter leads to terminals No. 4 and 8. Turn control switch to FIX/SET position. If resistance is zero ohms, go to next step. If resistance is infinite ohms, replace control switch or repair open in circuit. Switch/Vent Valve Check 1. With ignition off, connect ohmmeter leads to CCU wiring harness connector terminals No. 5 and 11. See Fig. 1 . Turn control switch to ON position. If resistance is zero ohms, go to next step. If resistance is infinite ohms, replace control switch, brake pedal vent valve or repair in open circuit. 2. With ignition off, leave ohmmeter leads connected to terminals No. 5 and 11. Leave control switch set to ON position. Apply brake pedal. If resistance is infinite ohms, go to next step. If resistance is zero ohms, replace brake pedal vent valve. Vacuum Pump Motor Check Turn ignition on. Using jumper wire, connect CCU wiring harness connector terminal No. 6 to ground. See Fig. 1 . Using jumper wire, apply battery voltage to terminal No. 7. If motor operates, go to next step. If motor does not operate, replace vacuum pump or repair open in circuit. Vent Valve Check Turn ignition on. Using jumper wire, apply battery voltage to CCU wiring harness connector terminal No. 7. See Fig. 1 . Using another jumper wire connected to ground, repeatedly touch terminal No. 12. If vent valve does not click, replace vacuum pump or repair open circuit. If vent valve clicks, check control unit, connector terminals and wiring harness connector. Repair or replace as necessary. REMOVAL & INSTALLATION BRAKE & CLUTCH VENT VALVES Removal WARNING: Cruise control unit is located behind glove box. See the AIR BAG RESTRAINT SYSTEM article before removing glove box. 1. Remove trim panel and vent duct from beneath left side of instrument panel. Brake and clutch switches are located on a bracket in front of associated pedal. 2. Disconnect wiring and vacuum hose from valve. With J-Shaped Tool (2041), remove vent valve from bushing by pulling J-shaped tool toward driver's seat. Installation Install brake or clutch vent valve into bushing until valve is seated in bushing. Pull back pedal as far as it will go. Slowly release pedal to adjust switch. CONTROL UNIT Remove glove box. See AIR BAG RESTRAINT SYSTEM article before removing glove box. Remove screw from rear side of instrument panel. Remove control unit from strap and disconnect electrical connector. To install, reverse removal procedure. STEERING COLUMN CONTROL SWITCH Remove steering wheel. See AIR BAG RESTRAINT SYSTEM article before removing steering wheel. Loosen steering column switch clamp and pull up steering column switch. Disconnect electrical connector and remove steering column control switch. To install, reverse removal procedure. VACUUM PUMP Remove coolant recovery tank. Remove screws and vacuum pump from fender. To install, reverse removal procedure. VACUUM SERVO 1. Detach linkage and remove vacuum hose from vacuum servo. Remove nut and servo from bracket. 2. To install, reverse removal procedure. Tighten retaining nut to 18 ft. lbs. (25 N.m). Set throttle in idle position. Install servo and turn adjuster nut so a .004-.012" (.10-.30 mm) gap exists between bushing and contact plate. VEHICLE SPEED SENSOR (VSS) VSS is installed on left side of transmission housing, near driveshaft flange. Remove VSS wiring harness connector and unscrew speed sensor from transmission. To install, reverse removal procedure. Fig. 1: Cruise Control Unit Wiring Harness Connector Terminals Courtesy of AUDI OF AMERICA, INC.


http://www.2carpros.com/forum/automotive_pictures/62217_Cruisea_1.jpg


If you remove the negative battery cable to dissable the air bags, know your radio codes if needed!
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Friday, September 24th, 2010 AT 3:24 PM

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