Suspension - Warning Lamp ON/DTC's C1770/C1845

Article No.
98-25-4

12/21/98

SUSPENSION - CHECK SUSPENSION LAMP
ILLUMINATED WITH DIAGNOSTIC TROUBLE CODE
(DTC) C1770 AND/OR C1845 STORED IN MEMORY -
VEHICLES BUILT THROUGH 10/1/1998

LIGHT TRUCK:
1997-99 EXPEDITION
1998-99 NAVIGATOR

ISSUE
Some vehicles equipped with air suspension may exhibit an intermittent check suspension lamp on and Diagnostic Trouble Code (DTC) C1770 and/or C1845 illuminated. Vehicles with these codes may not exhibit any ride height concerns. This may be caused by the air suspension control module.

ACTION
Replace the air suspension control module with a revised air suspension control module and recalibrate ride height. Refer to the following Service Procedure for details.

SERVICE PROCEDURE

1. Connect New Generation Star (NGS) Tester and go to Air Suspension menu to retrieve stored codes. Confirm that you have code C1770 and/or C1845 in memory. If you have any other codes, proceed with appropriate pinpoint tests in the 1998 Expedition/Navigator Workshop Manual, Section 204-OSA (Rear) or 204-05B (4-Wheel).

2. With NGS Tester, run the air suspension On-Demand self test. If you have any codes, proceed with appropriate pinpoint tests in the Workshop Manual, Section 204-OSA or 204-05B.

3. With NGS Tester, select Active Command Modes menu and manually raise and lower vehicle per Ride Height Adjustment procedure, 1998 Workshop Manual, Section 204-OSA or 204-05B. Monitor vehicle height changes. If vehicle does not respond, follow pinpoint tests for pneumatic failures. If vehicle does function properly, continue with Step 4.

4. Replace air suspension control module per the 1998 Workshop Manual, Section 204-OSA or 204-05B.

NOTE
A NEW OR EXCHANGED AIR SUSPENSION CONTROL MODULE REQUIRES THAT THE RIDE HEIGHT ADJUSTMENT CALIBRATION PROCESS BE PERFORMED; REFER TO FRONT RIDE HEIGHT RESETTING-CLEAR B2140 DTC.

PART NUMBER PART NAME

F7SZ-5A919-DB Air Suspension Module (1997-98)
XL1Z-5A919-AA Air Suspension Module (1999)

OTHER APPLICABLE ARTICLES: NONE
WARRANTY STATUS: Eligible Under The Provisions Of Bumper To Bumper Warranty Coverage

OPERATION DESCRIPTION TIME

982504A Perform Diagnostics, Install 1.2 Hrs.
Air Suspension Module,
And Perform Ride Height
Adjustment Calibration
Process

DEALER CODING
CONDITION
BASIC PART NO. CODE
5A919 42

OASIS CODES: 206000, 304000