TSB
01-1-9 DRIVEABILITY - HESITATION WHEN COLD - WITH NO DIAGNOSTIC TROUBLE CODES (DTC) PRESENT - VEHICLES EQUIPPED WITH 4.6L ENGINE AND MANUAL TRANSMISSION
Publication Date: JANUARY 11, 2001
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).
ACTION:
If condition is verified and normal diagnosis cannot pinpoint condition, reprogram the PCM to the latest level calibration. Refer to the following PCM Calibration Information Chart. Refer to the appropriate year Mustang Workshop Manual for reprogramming procedures.
PCM CALIBRATION INFORMATION
Application Old Part Number (-12A650-) Tear Tag New Part Number (-12A650-) Old Calibration New Calibration NGS/WDS Qualifier
1999 - 4.6L 2V T-45, Fed., 16 inch tires XR3F-ZD FTL3 XU7Z-AAA 9VXM-AAC 9VXM-AAC N/A use WDS
1999 - 4.6L 2V T-45, Fed., 17 inch tires XR3F-AAD GTG3 XU7Z-ABA 9VXM-ABC 9VXM-ABC N/A use WDS
1999 - 4.6L 2V T-45, Calif., 16 inch tires XR3F-ABE HJX4 XU7Z-ACA 9VMM-BAD 9VMM-BAD N/A use WDS
1999 - 4.6L 2V T-45, Calif., 17 inch tires XR3F-ACE JKU4 XU7Z-ADA 9VXM-BBD 9VXM-BBD N/A use WDS
2000 - 4.6L 2V T-45, Calif., 16 inch tires YR3F-DA KPL0 YU7Z-CMA 0ZE2GB0B00 0ZE2GB0B00 N/A use WDS
2000 - 4.6L 2V T-45, Calif., 17 inch tires YR3F-EA JRX0 YU7Z-CNA 0ZE2GAB0B0 0ZE2GA0B00 N/A use WDS