FIRM_SFT in DRIVE MODE

This OSC function is used to raise pressure during an upshift to determine whether the pressure control system is functioning correctly. Harsher shifts indicate that the pressure control system works at higher pressure. The best test for isolating pressure control system problems is to carry out the PCA, PCB, PCC in BENCH MODE using a hydraulic pressure gauge.

The OSC functions for the parameter FIRM_SFT allows the technician to choose the following options:

• FIRM_SFT - activates the harsh shift channel.
  • ON - sets control pressure higher for all upshifts (determined by the PCM)
  • OFF - sets control pressure to normal for all upshifts (determined by the PCM)
  • XXX - cancel OSC for FIRM_SFT

OSC "FIRM_SFT" DRIVE MODE operates ONLY when:

• VSS and digital TR sensor are operational.
• No VSS and digital TR sensor DTCs.
• Transmission range selector lever in O/D.
• Pressure gauge installed (optional).
• Key ON.
• Engine ON.
• Vehicle speed greater than 3 km/h (2 mph).
• TCC is OFF (TCC is not engaged).

OSC Command Values

• ON - sets control pressure high for all upshifts (determined by the PCM)
• OFF - sets control pressure to normal for all upshifts (determined by the PCM)
• XXX - cancel OSC for FIRM_SFT
• SEND - sends the values to the PCM

DRIVE MODE Procedure for FIRM_SFT

Follow operating instructions from the NGS menu screen.

• Select "Output State Control".
• Select "Trans - Drive Mode".
• Select "PIDs" to be monitored.
• Monitor all selected PIDs during test.
• Select "Parameters - FIRM_SFT.
• Press "SEND" to send command.
• Select "XXX" to cancel at any time.
• Press "SEND".