PCM - Hesitation/Rough Idle On Warm Startup
Article No.00-10-2
05/15/00
^ HESITATION - DURING STARTUP AFTER HOT
SOAK - 2.5L VEHICLES BUILT THROUGH 5/1/2000
^ ROUGH IDLE - DURING STARTUP AFTER HOT
SOAK - 2.5L VEHICLES BUILT THROUGH 5/1/2000
FORD:
1999-2000 CONTOUR
MERCURY:
1999-2000 COUGAR, MYSTIQUE
ISSUE
Some vehicles may exhibit a rough idle, or hesitation when first operated after being parked for 20-30 minutes (also known as a hot soak condition). This may be due to the presence of winter grade fuels along with the existing Powertrain Control Module (PCM) calibration. The present calibration may not increase the fuel pressure sufficiently when first started after a hot soak to compensate for the winter grade fuels. This may result in fuel vapor (instead of liquid fuel) accumulating in the fuel rail and ultimately being directed to the cylinders through the injectors.
ACTION
Reprogram the PCM with a new calibration which has a revised fuel pressure strategy. Refer to the following Service Procedure for details.
SERVICE PROCEDURE
1. Perform the diagnostic self-test to check for Diagnostic Trouble Codes (DTCs). If any codes are present, refer to the appropriate diagnostic routines in the Powertrain Control/Emissions Diagnosis (PC/ED) Service Manual and repair as necessary.
2. Using the New Generation Star (NGS) Tester or Worldwide Diagnostic System (WDS), access the PCM identification function (Log File on WDS) to obtain the present part number of the PCM.
3. Use the PCM part number to identify the vehicle's existing calibration by referring to the following PCM Reprogramming Information Chart.
4. Once the existing calibration has been identified, reprogram the PCM to the latest calibration revision level using an NGS Tester or WDS.
NOTE:
AFTER A MODEL YEAR GOES OUT OF PRODUCTION, THE SERVICE CALIBRATION SUFFIX IS NOT CHANGED. ONLY THE PCM PART NUMBER IS UPDATED WHEN THE PCM IS RECALIBRATED.
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.
OTHER APPLICABLE ARTICLES: NONE
WARRANTY STATUS: Eligible Under The Provisions Of Bumper To Bumper Warranty Coverage
OPERATION DESCRIPTION TIME
001002A Reprogram Powertrain 0.6 Hrs.
Control Module (PCM)
DEALER CODING
CONDITION
BASIC PART NO. CODE
RECAL 42
OASIS CODES: 602300, 603300, 607000, 607400, 607500, 607700, 608000, 608400, 608500, 609000, 609400, 610000, 610500, 611000, 611500, 612000, 612500, 614000, 614500, 618400