|
| FORD: | 1997-1999 CROWN VICTORIA, MUSTANG, ECONOLINE, EXPEDITION, EXPLORER, F-150, F-250 LD |
| LINCOLN: | 1997-1998 MARK VIII 1997-1999 TOWN CAR |
| MERCURY: | 1997-1999 GRAND MARQUIS, MOUNTAINEER |
A perceived 2-3 delayed upshift, primarily when the transmission is cold, may be evident on some vehicles.
The Powertrain Control Module (PCM) strategy is designed to delay shifts in some vehicles when Transmission Fluid Temperature (TFT) is below approximately 21°C (70°F) for faster heater warmup.
The 2-3 shift may be delayed approximately 14-24 km/h (9-15 mph) when compared to the shift speed charts listed in the appropriate Service or Workshop Manual.
A leaking 2-3 accumulator may cause Diagnostic Trouble Code (DTC) P0782.
ACTION:
Verify if delayed upshift is normal cold shift scheduling or a possible leak past the large diameter 2-3 accumulator seal. Refer to the following Service Procedure for details.
SERVICE PROCEDURE
- Using New Generation Star (NGS) Tester or Scan Tool, perform all self tests and record DTCs.
- Monitor rpm, and gear command Parameter Identification Displays (PIDs) with the NGS Tester during the 2-3 shift.
- If engine rpm decreases within 1-2 seconds after the gear command has changed on the NGS Tester, then vehicle has upshifted properly and no repair is necessary. If engine rpm does not drop within 1-2 seconds, continue to Step 4.
- If engine rpm does not drop when the PCM commands third gear, then replace the 2-3 accumulator piston using the revised Accumulator Piston (F7AZ-7H292-AB). Refer to the appropriate Service or Workshop Manual for replacement procedure.
