Diagnostic Aids
WARNING: This page does not describe the selected car, but rather 10 other vehicles, including the 2002 Ford RV Cutaway, 2002 Ford Pickup, 2002 Ford F550 Super Duty, 2002 Ford F450 Super Duty, and 2002 Ford Excursion. However, it is still accessible from the selected car via links, so may be relevant.
Perform this test only when directed by QUICK TEST. This test is only intended to diagnose the following components and circuits:
- Wiring Harness Circuits (ASM, ASMM, B+ & VPWR)
- Blown Battery Junction Box Fuse No. 10 (15-Amp)
- Downshift Solenoid
- Downshift Solenoid Relay
- Powertrain Control Module (PCM)
NOTE:
Kickdown Solenoid Relay is used on F650-750 with an Allison AT545 automatic transmission only.
On F650-750, PCM controls a relay which provides kickdown necessary for Wide Open Throttle (WOT) downshifts. Downshift solenoid relay is powered through VPWR circuit. When PCM sends a signal to downshift solenoid relay control (ASM) circuit, it causes downshift solenoid relay to switch voltage from battery junction box fuse No. 10 (15-Amp) to positive side of transmission mounted downshift solenoid. PCM monitors switched side of relay through terminal No. 40 for diagnostics.