PCM - Hesitation Backfires When Cold

Article No.
01-1-9

01/22/01

DRIVEABILITY - HESITATION WHEN COLD - WITH NO
DIAGNOSTIC TROUBLE CODES (DTC) PRESENT -
VEHICLES EQUIPPED WITH 4.6L ENGINE AND
MANUAL TRANSMISSION

FORD:
1999-2000 MUSTANG

ISSUE
Some vehicles may exhibit a hesitation and in some cases engine backfiring through the induction system on cold starts (27°C/80°F and colder) with no diagnostic trouble codes (DTC) present. The hesitation is exhibited on a low speed, high load condition. This may be caused by the calibration of the Powertrain Control Module (PCM).





Obtain an Authorized Modifications Decal (FPS 8262 - obtainable through DOES II, 25/pkg) and list the date, dealer number, and summary of modifications 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.

ACTION





If condition is verified and normal diagnosis cannot pinpoint condition, reprogram the PCM to the latest level calibration. Refer to the PCM Calibration Information Chart as shown. Refer to the appropriate year Mustang Workshop Manual for reprogramming procedures.

OTHER APPLICABLE ARTICLES: NONE
WARRANTY STATUS: INFORMATION ONLY
OASIS CODES: 807000, 607400, 608000, 608400, 609000, 609400, 611000, 611500, 613000, 613400