PCM - MIL ON/Code 41 Set/No Driving Concerns
Article No.94-18-9
09/07/94
LAMP - "MALFUNCTIONING INDICATOR LIGHT" - ON AND CODE 41 IN CONTINUOUS MEMORY - 5.0L WITH AOD AND MANUAL TRANSMISSION
LIGHT TRUCK:
1992-93 BRONCO, F-150
This TSB article is being republished in its entirety to include the latest level Powertrain Control Modules (PCM).
CALIBRATION:
2-54J-ROO, 2-54J-R10, 3-54J-R10, 2-54W-R00, 2-54W-R10, 3-54W-R10, 2-54E-R00, 2-54E-R10, 3-54E-R10, 2-54Z-R00, 2-54Z-R10, 3-64Z-R10, 2-53E-R00, 2-53E-R10, 2-53F-R00, 2-53F-R10
WARNING:
THIS MODIFICATION IS AUTHORIZED ONLY FOR THE LISTED ENGINE. PERFORMING THIS MODIFICATION ON OTHER ENGINE CALIBRATIONS IS UNAUTHORIZED AND COULD CREATE LIABILITY UNDER APPLICABLE FEDERAL OR LOCAL LAWS.
ISSUE:
Vehicles equipped with 5.0L engines and AOD or manual transmissions may exhibit a Check Engine Light, "MIL", ON and code 41 in continuous memory. No driveability concerns are encountered. This is due to the limitation of the PCM strategy. The "MIL" is activated when the driver enters a steady state cruise condition after a cold start or tips in and/or out of the throttle more than ten (10) times before the H02S switches eight (8) times.
ACTION:
Diagnose for proper operation of the "MIL" light. Refer to the following procedure for service details.
SERVICE PROCEDURE
1. Follow the appropriate Quick Test Procedure in the 1992 or 1993 Powertrain Control/Emission Diagnostic Manual for "MIL" light.
2. If a code 41 appears in continuous memory and fault codes appear in the KOEO (Key On Engine Off) or KOER (Key On Engine Running) tests, other concerns may be occurring. Service them as required.
NOTE:
DO NOT REPLACE THE PROCESSOR UNTIL BOTH KOEO AND KOER SHOW PASS CODE (11).
3. If a code 41 appears in continuous memory and pass code 11 appears in the KOEO or KOER tests, then replace the PCM using the PCM Reference Chart in this article.
4. If a processor change is made, gap the spark plugs at 0.052-0.056" (1.32 mm-1.42 mm). Refer to the NOTE following the PCM Reference Chart.
Obtain an Authorized Modifications Decal and list the date, dealer number, and summary of alterations performed. Select a prominent place adjacent to the Vehicle Emission Control Information Decal suitable for installing the Authorized Modifications Decal. Clean the area, install the decal, and cover it with a clear plastic decal shield.
NOTE:
BE SURE TO INDICATE THE NEW CALIBRATION NUMBER ON THE MODIFICATION LABEL.
NOTE:
WITH THE PCM CHART ABOVE, THE SPARK PLUG GAPS HAVE CHANGED. THE FORMER R00 LEVEL CALIBRATIONS HAD THE SPARK PLUGS GAPPED AT 0.042-0.046" (1.07 mm - 1.17 mm). THE R10 LEVEL CALIBRATIONS SHOULD HAVE THE SPARK PLUGS GAPPED AT 0.052-0.056, (1.32 mm - 1.42 mm).
Parts Block
OTHER APPLICABLE ARTICLES: NONE
SUPERSEDES: 93-16-11
WARRANTY STATUS: Eligible Under Bumper To Bumper And Emissions Warranty Coverage
OPERATION DESCRIPTION TIME
941809A Perform Quick Test, 1.8 Hrs.
Replace PCM, Re-gap
Spark Plugs, Perform Final
Quick Test
DEALER CODING
BASIC PART NO. CONDITION CODE
12A650 08
OASIS CODES: 206000, 690000, 698298