Transmission Failure Mode Effects Management, Shift Concerns: Erratic/Hunting or Erratic Scheduling

WARNING: This page is about a different car, the 2011 Ford F550 Super Duty and 2011 Ford F450 Super Duty. However, it is still accessible from the selected car via links, so may be relevant.

DIAGNOSTIC ROUTINES - TRANSMISSION FAILURE MODE EFFECTS MANAGEMENT, SHIFT CONCERNS: ERRATIC/HUNTING OR ERRATIC SCHEDULING

Possible Component	Reference/Action
265 - ROUTINE
Powertrain Control System	CARRY OUT On-Board Diagnostic (OBD) tests. REFER to the INTRODUCTION article for diagnosis and testing of the PCM. For diagnosing TFT sensor, GO to PINPOINT TEST B . For diagnosing TR sensor, GO to PINPOINT TEST C . For diagnosing TSS /intermediate shaft speed and OSS sensor, GO to PINPOINT TEST D . REPAIR as necessary. CLEAR the DTCs, ROAD TEST the vehicle and RERUN the OBD test. REFER to Routine 212.
PCM, vehicle wiring harnesses, transmission internal harness, Turbine Shaft Speed (TSS)/intermediate shaft speed sensor, Output Shaft Speed (OSS) sensor, Transmission Range (TR) sensor, Transmission Fluid Temperature (TFT) sensor, Transmission Control Indicator Lamp (TCIL), tow/haul switch, Transmission Solenoid Power Control driver circuit
The transmission Failure Mode Effects Management serves 3 purposes: Prevents invalid combinations of applied clutches that cause tie-ups Isolates a potential fault down to a specific pressure switch, solenoid or clutch Limits gears of operation based on the failure after the fault had been isolated	When failures occur the customer may complain of erratic shifting or transmission hanging in gear. This is normal for the Failure Mode Effects Management strategy. DETERMINE which gears are being commanded, and which gears are being avoided, and this will in turn point to a specific pressure switch, solenoid or clutch fault.