EGR System - MIL ON Intermittently
CATEGORYEngine
SECTION
2
PAGE
24
ISSUE
10/92-0264
CODE
254
Subject:
EGR System
Application:
900 Turbocharged models with EGR 1990-1992
This PSI was also released in September, 1992 as an Emission Recall (281), applicable only in the State of California. The recommendations herein may be followed to correct a complaint of intermittent illumination of the Malfunction Indicator Lamp (CHECK ENGINE lamp) related to the EGR system. This is not a campaign or a service directive.
Under certain operating conditions, such as prolonged deceleration, or very light throttle cruise, exhaust gas temperature may drop below the sensor threshold for the On-Board Diagnostic monitoring system. The LH Electronic Control Module (ECM) will then light the MIL, falsely indicating that there is no exhaust gas recirculation (EGR) flow under operating conditions in which there ought to be. Follow the Action below to rectify this complaint.
Cars Affected:
1990-1992 900 Turbocharged models with EGR
Parts Required
Action:
Remove the EGR system and fit a new LH ECM as follows:
1. Remove the EGR valve retaining bolts and remove the EGR pipe from the exhaust manifold. Lift out the valve and pipe (figure 1).
Plug the pipe connection in the exhaust manifold by means of threaded plug P/N 81 23 739 and replace the EGR valve with plate P/N 93 58 177, gasket P/N 75 07 973 and two bolts 80 19 887.
2. Remove the modulating valve and vacuum hoses (figure 2).
3. Remove the vacuum tank and its vacuum hoses. Plug the hose connection on the intake pipe and the nipple on the pressure pipe by means of rubber plug P/N 83 35 614 (figure 3).
4. Fit a new LH ECM, P/N 02 42 172 (see figure 4).
5. Remove the existing emission control label (using a heat gun), clean the surface and affix a new emission control label on the left-hand inner fender in front of the fuse box (figure 5).
6. Test drive the vehicle, ensuring that all systems are operational.
Warranty Information:
For owner complaints arising under warranty, use failure coding 25439-67-0-01-06. Time allowance is Labor Operation Numbers 24810 (0.2), 25430 (0.2). 25433 (0.2), 25461 (0.2) and 0.4 hour in straight time.