Diagnostic Aids
WARNING: This page is about a different variant/trim than selected.
NOTE:
After each service or repair procedure has been completed, reconnect all components. Clear DTCs and repeat QUICK TEST procedures to ensure all electronic engine control systems are working properly and DTCs are no longer present.
NOTE:
Kickdown Solenoid Relay is also referred to as downshift solenoid relay or shift control modulator relay.
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.