EEC Processor - MIL ON/Code 173 Set

Article No.
92-18-12

08/26/92

LAMP - "MALFUNCTIONING INDICATOR LAMP" - ON AND CODE 173 (HEGO INDICATING RICH) IN CONTINUOUS MEMORY - 5.8L WITH E40D TRANSMISSION

LIGHT TRUCK:
1991-92 BRONCO, ECONOLINE, F-150-350 SERIES

CALIBRATION:
1-64E-R10, 2-64E-R10, 1-64H-R10,
2-64H-R10, 2-64K-R00, 1-64M-R10,
2-64M-R10, 1-64P-R10, 2-64P-R10,
2-64R-R00, 1-64R-R10, 2-64S-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 5.8L engines and E40D transmissions may exhibit a Check Engine Light "MIL", On and code 173 in continuous 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 no HEGO switching during VP test conditions and activates the MIL light.

ACTION:
Diagnose for proper operation of the "MIL" Light. Refer to the following procedure for service details.

SERVICE PROCEDURE

1. Following the appropriate Quick Test Procedure in the 1992 Powertrain Control/Emission Diagnostic Manual for "MIL" light.

2. If a code 173 appears in continuous memory and pass code 111 appears in the KOEO (Key Engine Off) and KOER (Key On Engine Running) Tests, then replace the EEC IV processor. Refer to the EEC IV Processor Reference Chart.

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

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





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





PART NUMBER

OTHER APPLICABLE ARTICLES:
NONE

WARRANTY STATUS:
Eligible Under Bumper To Bumper And Emissions Warranty Coverage

OPERATION DESCRIPTION TIME
921812A Perform EEC IV Quick Test 0.5 Hr.
921812B Perform EEC IV Quick Test 0.9 Hr.
Replace EEC IV Processor
And Install Modification Decal

DEALER CODING
BASIC PART NO. CONDITION CODE
12A650 08

OASIS CODES:
206000