LEMON Manuals: Even more car manuals for everyone
Home >> Porsche >> 1988 >> 944 Base, Standard >> Repair and Diagnosis (Single Page) >> Accessories & Equipment >> Cruise Control Systems >> Testing >> Control Unit Testing >> 911 Series

911 Series

  1. Disconnect harness plug at control unit. Control unit is located behind a cover in luggage compartment. Following tests should be made at harness plug. See Figure .
  2. Ensure ignition switch is in "OFF" position. Check for continuity between terminal No. 3 and ground. When clutch pedal is depressed, resistance should be 10 ohms. If there is no resistance with pedal depressed, suspect defective switch or disconnected (or defective) solenoid on servo unit.
  3. Measure resistance between terminal No. 17 and ground. Resistance should be 11-17 ohms. If not, replace servo.
  4. Terminal No. 12 is a direct ground connection. Terminal No. 11 should receive a pulse signal when speedometer moves. Rotate one rear wheel and check with ohmmeter.
  5. Check brake light operation. If okay, terminal No. 6 should be open.
  6. Turn ignition switch to "ON" position. Connect voltmeter to terminal No. 6. With brake pedal depressed, battery voltage should be present.
  7. Hold control switch lever in upward position. Battery voltage should be present at terminal No. 9.
  8. Check for battery voltage at terminal No. 8. Circuit should be open when control lever is moved toward steering wheel.
  9. Move control lever downward. Battery voltage should be present at terminal No. 10. Repair or replace defective switch controls or wiring as necessary. If defective control unit is suspected, test by substitution.
scientia non olet · About LEMON Manuals