PCM - MIL ON/Code 173 Set

9235ford02

Article No.
92-15-13

07/15/92


LAMP - "CHECK ENGINE" MALFUNCTION INDICATOR LIGHT (MIL) LIT - SERVICE CODE 173 IN CONTINUOUS MEMORY - VEHICLES WITH 5.0L AND E40D


LIGHT TRUCK:
1992 BRONCO, F-150, F-250


CALIBRATION:
2-54L-R00, 2-54L-R10, 2-54X-R00, 2-54X-R10, 2-54P-R00, 2-54P-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:
The "Check Engine" Malfunction Indicator Light may be lit and service code 173 (HEGO indicating Rich) stored in memory. The strategy is performing the HEGO Test during open-loop engine operation. This, in combination with a Green Vehicle KAM (Keep Alive Memory), results in a no HEGO switching situation during VIP test conditions and activates the MIL Light. No driveability symptoms exist.

ACTION:
Replace the EEC IV Processor if, after performing the appropriate Quick Test Procedure in the 1992 Powertrain Control/Emissions Diagnosis Service Manual, the KOEO (Key On Engine Off) and KOER (Key On Engine Running) Tests show Pass Code "111". Refer to the following procedure for service details.


1. Follow the appropriate Quick Test Procedure in the 1992 Powertrain Control/Emissions Diagnosis Service Manual for "MIL" Light.

2. If a code 173 appears in continuous memory, and Pass Code "111" appears in the KOEO (Key On Engine Off) and KOER (Key On Engine Running) Tests, then replace the EEC IV Processor. Refer to the EEC IV Processor Reference Chart in this article for correct parts usage.


3. If a code 173 appears in continuous memory, and fault codes appear in the KOEO or KOER tests, other concerns may be occurring. Service as required.

NOTE:
DO NOT REPLACE THE PROCESSOR UNTIL BOTH KOEO AND KOER SHOW PASS CODES.

4. If a processor change is made, the spark plugs need to be gapped at 0.052-0.056" (1.32-1.42 mm). (Refer to the note that follows the EEC IV Processor 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.





EEC IV PROCESSOR REFERENCE CHART


NOTE:
PER THE CHART ABOVE, THE ROO LEVEL CALIBRATIONS HAVE THE SPARK PLUGS GAPPED AT 0.042-0.046" (1.07-1.17 MM). THE R10 AND R12 LEVEL CALIBRATIONS SHOULD HAVE THE SPARK PLUGS GAPPED AT 0.052-0.056" (1.32-1.42 MM). FOR THE PROCESSORS IN THE CHART ABOVE, AN R11 LEVEL CALIBRATION DOES NOT EXIST.

PART NUMBER PART NAME CLASS

F2TZ-12A650-AHB EEC (V Processor (49 State) B
F2TZ-12A650-AKB EEC IV Processor (Altitude) B
F2TZ-12A650-AJB EEC IV Processor (California) W


OTHER APPLICABLE ARTICLES:
92-4-4
WARRANTY STATUS:
Eligible Under Bumper To Bumper Warranty Coverage, Emissions Warranty Coverage
OPERATION DESCRIPTION TIME
921513A Perform Diagnostics 1.5 Hrs.
921513B Perform Diagnostics, 2.4 Hrs.
Replace EEC IV Processor,
Reset Spark Plug Gap And
Install Modification Decal.
DEALER CODING
BASIC PART NO. CONDITION CODE
12A650 08
OASIS CODES:
206000