Cruise Control - Troubleshooting With Breakout Box: Overview

CATEGORY
Electrical

SECTION
3

PAGE
26

ISSUE
07/92

CODE
368

Subject:
Troubleshooting Cruise Control
System With Breakout Box

Application:
1992 900 and 9000 Models





A new Cruise Control Electronic Control Unit (ECU) incorporating a released 15-pole connector was introduced on 1992 900 and 9000 models. This new ECU makes it impossible to use the Cruise Control Tester (figure 1) for diagnostic purposes on these models. Instead, Breakout Box (P/N 86 11 006) and Cable (P/N 86 11 121) (figure 2) must be used to troubleshoot the Cruise Control Systems on 1992 900 and 9000 models.

Note that the same troubleshooting procedures outlined here using the Breakout Box can also be used by hooking up a jumper wire to the back of the connector housing of the disconnected ECU.

Cars Affected:



All 1992 900 models

All 1992 9000 models without TCS

Parts:

Breakout Box 86 11 006

Breakout Box Cable 86 11 121

Action:


Before starting any work, be sure to check the following points:

1. 900:
Check that voltage is present at fuse 8 on manual transmission vehicles and at fuses 8 and 13 on automatic transmission cars.

9000:
Check that voltage is present at fuse 2 on manual transmission vehicles and at fuses 2 and 9 on automatic transmission cars.

2. Disconnect vacuum pump 187 and connect an external vacuum source (hand-held vacuum pump) to vacuum hose. Create a vacuum and make sure there are no leaks within the vacuum system and that the butterfly flap moves.

If there is leakage, check:

^ all hoses

^ vacuum regulator

^ pedal switches



If the butterfly valve does not move, even though there is vacuum, the ball valve between the vacuum regulator and the throttle pedal may be loose. This check can also be done with the Breakout Box. See step 6, Vacuum Hoses.