EGR - Intermittent MIL ON/Multiple DTC's Set
Article No.96-23-4
11/04/96
^ DETONATION - 4.6L - INTERMITTENT MALFUNCTION INDICATOR LAMP (MIL) ILLUMINATION - DIAGNOSTIC TROUBLE CODES (DTCS) 332, P1407 AND/OR P1408 UNDER NORMAL DRIVING CONDITIONS
^ MALFUNCTION INDICATOR LAMP (MIL) - INTERMITTENT ILLUMINATION - DIAGNOSTIC TROUBLE CODES (DTCS) 332, P14O7 AND/OR P1408 - 4.6L - DETONATION UNDER NORMAL DRIVING CONDITIONS
FORD:
1992-95 CROWN VICTORIA
1994-95 THUNDERBIRD
LINCOLN-MERCURY:
1991-95 TOWN CAR
1992-95 GRAND MARQUIS
1994-95 COUGAR
This TSB article is being republished in its entirety to include two additional Diagnostic Trouble Codes (DTCs) for vehicles with OBD II systems.
ISSUE:
Detonation and/or Malfunction Indicator Lamp (MIL) illumination with DTCs 332, P1407, and/or P1408 may occur under normal driving conditions. This is due to carbon buildup in the Exhaust Gas Recirculation (EGR) groove of the intake manifold (throttle body base).
ACTION:
Refer to the following Service Procedure for details.
SERVICE PROCEDURE
1. Perform "DL" Pinpoint Test as instructed in the appropriate year Powertrain Control/Emissions Diagnosis (PC/ED) Service Manual.
2. If Step 1 does not solve the concern, refer to the appropriate year PC/ED, Section 10A, EGR System Functional Diagnosis, and perform the tests involved.
3. If engine rpm does not change when performing test "EGR3" of Step 2, and the EGR valve checks good, check the EGR passage between the intake manifold and the throttle body for carbon blockage (Figure 1).
a. Remove the throttle adapter from the intake manifold. Refer to the appropriate model/year Service Manual, Section 03-01, for service procedure.
b. Keep objects from entering into the intake manifold by covering the opening.
c. Using an appropriate size chisel, remove carbon deposits that have accumulated in the EGR groove (Figure 2) on the intake manifold or sealing surfaces.
CAUTION:
USE CARE AS NOT TO DAMAGE SEALING SURFACES OF INTAKE MANIFOLD.
d. Brush off all carbon that has been removed, wash EGR groove and adapter surface with suitable solvent.
e. Replace Intake Manifold-to-Throttle Body Adapter Gasket (F1AZ-9H486-A).
f. Reinstall throttle body and adapter assembly. Refer to appropriate model/year Service Manual, Section 03-01, for correct torque specifications.
PART NUMBER PART NAME
F1AZ-9H486-A Gasket - Intake Manifold-To-Throttle Body Adapter
OTHER APPLICABLE ARTICLES: NONE
SUPERSEDES: 95-18-3 950911
WARRANTY STATUS: Eligible Under The Provisions Of Bumper To Bumper Warranty Coverage And Emissions Warranty Coverage
OPERATION DESCRIPTION TIME
962304A Clean Carbon From EGR 0.6 Hr.
Groove At Throttle Body -
Air By-Pass - All Models
DEALER CODING
CONDITION
BASIC PART NO. CODE
9A589 55
OASIS CODES: 206000, 615000, 698298