INTERMITTENT IWE NOISE, 4WDH LIGHT AND/OR 4X4 SYSTEM INOPERATIVE, DTCS—C1979 AND C1980

TSB 06-8-15

Some 2004-2006 F-150 and 2006 Mark LT 4X4 vehicles built before 4/24/2006 may exhibit a noise in 2 wheel drive from the front Integrated Wheel Ends (IWE) and/or the 4X4 system being inoperative. The IWE solenoid may have ingested water and passed it to the IWE system causing water contami

nation in the vacuum portion of the system. A shorted IWE solenoid can set the codes C1979 and C1980. If either code is present, the 4WDH light will be inoperative.

ACTION

Use the following Service Procedure to check and repair the 4X4 system.

SERVICE PROCEDURE

1. Replace the IWE solenoid. Torque the new design bracket and solenoid to 62 lb-in (7 N•m). It will be necessary to remove the  vacuum lines from each IWE down at the wheels to check for water being present.

a. If no water is present at the vacuum line at the IWE, install the new solenoid with bracket. Reconnect all vacuum hoses.

b. If water is present allow it to drain from the vacuum lines. Then follow the updated procedure outlined in 2006 Workshop Manual (WSM) on-line version, Section 308-07A, Pin Point Tests B21 and B22. These tests checks IWE leak rates with vacuum and will remove any residual water from the IWE. Reconnect all vacuum hoses.

2. If the IWE looses vacuum quicker than specification. Refer to WSM, Section 204-01B for normal diagnostic procedures.

PART NUMBER: 6L3Z-9E441-A

PART NAME: IWE Solenoid

WARRANTY STATUS: Eligible Under Provisions Of New Vehicle Limited Warranty Coverage

OPERATION: 060815A

DESCRIPTION: 2004-2006 F-150 4X4 and 2006 Mark LT 4X4: Check Diagnostic Trouble Codes And Replace The IWE Solenoid (Includes Time To Check For Water At The Wheels) (Do Not Use With 12650D).

TIME: 0.5 HRS

OPERATION: MT060815

Claim Additional Labor Required As Actual Time Or Use SLTS Operation If available.

TIME: Actual

DEALER CODING:

BASIC PART NO. 9E441

CONDITION CODE: 42