Windstar V6-232 3.8L (1995)
General Module: All Technical Service Bulletins
Air Suspension (Rear) - Warning Lamp ON/DTC C1818 Set
Article No.
97-16-8
08/04/97
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SUSPENSION - REAR - LOAD LEVELING REAR AIR
SUSPENSION WARNING LAMP ILLUMINATED -
DIAGNOSTIC TROUBLE CODE (DTC) C1818
STORED IN MEMORY - VEHICLES BUILT THROUGH
9/97
^
LAMP - LOAD LEVELING REAR AIR SUSPENSION
WARNING LAMP ILLUMINATED - DIAGNOSTIC
TROUBLE CODE (DTC) C1818 STORED IN
MEMORY - VEHICLES BUILT THROUGH 9/97
LIGHT TRUCK:
1995-98 WINDSTAR
This TSB article is being republished in its entirety to correct a service part number and expand service procedure.
ISSUE:
The load leveling rear air suspension warning lamp may be illuminated intermittently with Diagnostic Trouble Code (DTC) C1818 stored in memory.
This may be caused by either line back pressure, piston connector rod position, low generator voltage, or connection corrosion.
ACTION:
Replace the Generic Electronic Module (GEM) with a revised strategy GEM. Refer to the following Service Procedure for details.
NOTE:
DO NOT USE THIS TSB IF CODES OTHER THAN C1818 HAVE BEEN SET IN THE VEHICLE'S MEMORY. REFER TO THE PINPOINT
TEST AS INDICATED IN THE APPROPRIATE YEAR WINDSTAR SERVICE MANUAL.
NOTE:
THE 1996 WINDSTAR SERVICE MANUAL SHOULD BE REFERENCED WHEN SERVICING 1995 WINDSTARS.
SERVICE PROCEDURE
It is imperative that concerns with the computer-controlled rear air suspension be diagnosed and serviced utilizing the Pinpoint Tests detailed in the
Windstar Service Manual, Section 04. Using this approach will eliminate the haphazard replacement of (expensive) components that may not be
defective. This TSB article outlines the Pinpoint Tests for diagnosing and servicing DTC 01818 only. There are several possible causes of DTC C1818,
most of which do not involve the GEM. Do not attempt to replace the GEM with the new service version unless instructed to do so by the Pinpoint Test.
Do not use this service procedure if the New Generation Star (NGS) Tester is displaying only codes other than C1818.
The new service GEM includes a rear air suspension strategy that is intended to purge the line pressure and retry the system prior to setting DTC 01818.
This strategy is intended to avoid intermittent illumination of the warning lamp caused by "normal" circumstances surrounding a compressor time-out
such as low generator voltage, crank position, line back pressure, etc. Again, note that by following the Service Manual Pinpoint Test procedure
carefully, causal factors such as corrosion of electrical connectors will be identified and eliminated prior to pinpointing the GEM.
Proper diagnosis of the computer-controlled rear air suspension requires the use of the NGS Tester. However, some versions of NGS software are not
compatible with the Rear Air Suspension (RAS) codes within GEM. Use the following as a guide to selecting the correct NGS software version.
In order to properly diagnose and repair DTC C1818 perform the following:
1.
Review the Diagnostic Instructions (appropriate model year Windstar Service Manual, Pages 04-05-14 and 04-05-15) regarding diagnosis using
the NGS Tester.
2.
Service all DTCs other than C1818 first, following the Pinpoint Test in the Windstar Service Manual.
