A/T - Idle Increase & Backup Light Malfunction
CATEGORYElectrical
SECTION
3
PAGE
39
ISSUE
02/93-0306
CODE
368
Subject:
Idling Increase Malfunction, Cruise Control, Automatic Transmission
Application:
1989-1993 900 Models
On 1989- 900 models, a new gear selector switch with a diode was introduced to give an idling increase signal also in reverse.
Upon replacement or removal of the gear selector switch or any of its connections, make sure to reconnect the leads as they were. There is a danger of mistaking the leads for each other and if this should happen, then:
^ +12 volts will be supplied continuously across the diode,
^ the fuel injection system will receive a continuous idling increase signal causing the idle to run several hundred RPM higher than normal.
^ the backup lights will be switched on even when the gear selector is in position D or 2.
CAUTION
Current through the diode in this situation will be too high for it, and it will be unable to be serviced.
Cars Affected:
All 1989-1993 900 model cars with automatic transmission and cruise control.
Fault Symptoms
1. The backup lights come on when the gear selector is in position D or 2 and the idling increase function is continuously engaged.
Possible Cause:
The diode is OK but the leads to the backup lights are not connected correctly.
2. Inoperative idling increase function/Cruise Control system.
Possible Cause:
The diode is not OK and the leads to the backup lights are not connected correctly.
3. No Idling increase in position R.
Possible Cause:
The diode is = OK and the leads are connected correctly.
Action:
1. Check that fuse 8 for the cruise control and fuse 13 for the backup lights are intact in the main fuse box in the engine bay.
2. Carefully remove the gear selector lever indicator cover and undo the selector lever center console at front and rear.
3. Check the electrical connections on thg gear selector switch, Figure 1.
White cable: should be connected to pin 2.
Blue/white and white lead: should be connected to pin 1.
If the leads are not connected correctly, change them as stated above.
4. Connect a volt meter to the orange lead connected to pin 3 and a good grounding point, such as the gear selector lever housing. Turn the ignition switch to the Drive position. The meter should now show battery voltage in positions R, D and 2 and 0-5 volts in the other positions.
a. If the meter shows 0-5 volts in position R and battery voltage in positions D and 2, the diode isn OK and a new gear selector switch, P/N A 95 64 733 should be fitted.
b. If the meter shows battery voltage in all positions, the leads to the backup lights are ne connected correctly. Switch the leads and take a new reading.
c. If the meter shows 0-5 volts in all positions, the diode is not OK and the leads to the backup lights are not connected correctly. Fit a new gear selector switch and make sure the leads are connected correctly.
5. When fitting a new gear selector switch, move the selector lever to the Neutral position. Turn the switch housing so that the switch lever is opposite the mark on the housing. Tighten the contact housing's two retaining screws.
6. Check the operation of the switch as in steps 3 and 4 above.
7. Refit the selector lever center console and selector lever indicator cover.
8. Drive the car and check the operation of the backup lights, neutral safety function, idling increase function and Cruise Control.