EPC in DRIVE MODE

This OSC function is used to increase the EPC pressure while testing the transmission shift functions. This OSC function can only increase the EPC pressure greater than what the PCM normally commands. If an OSC value, such as 75 or 90 psi is sent, the upshifts and downshifts should exhibit a harsher shift. Harsher shifts would indicate that the EPC pressure control works at higher pressures. The best test for the EPC is to use the BENCH MODE and a hydraulic pressure gauge. Using EPC in the BENCH MODE will confirm that the EPC works at both the higher and lower pressures.

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

• EPC - activates EPC to selected
  • 00 - sets EPC pressure to 0 psi.
  • 15 - sets EPC pressure to 15 psi.
  • 30 - sets EPC pressure to 30 psi.
  • 45 - sets EPC pressure to 45 psi.
  • 60 - sets EPC pressure to 60 psi.
  • 75 - sets EPC pressure to 75 psi.
  • 90 - sets EPC pressure to 90 psi.

OSC "EPC" 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.
• Key ON.
• Engine ON.
• Vehicle speed greater than 2 mph.
• OSC value for EPC must be greater than what the PCM commands (see EPC PID).

OSC Command Values

• 00 - sets EPC pressure to 0 psi.
• 15 - sets EPC pressure to 15 psi.
• 30 - sets EPC pressure to 30 psi.
• 45 - sets EPC pressure to 45 psi.
• 60 - sets EPC pressure to 60 psi.
• 75 - sets EPC pressure to 75 psi.
• 90 - sets EPC pressure to 90 psi.
• OFF - turns solenoid OFF.
• ON - turns solenoid ON.
• XXX - cancels OSC value sent.
• SEND - sends the values to PCM.

DRIVE MODE Procedure for EPC.

Follow operating instructions from the scan tool menu screen.

• Select "Output State Control."
• Select "Trans - Drive Mode."
• Select "PIDs" to be monitored.
• Monitor all selected PIDs during test.
• Select "Parameters - EPC."
• Select Value "0-90 psi."
• Press "SEND" to send command.
• Re-Select Value "0-90 psi."
• Press "SEND" to send command.
• Select "XXX" to cancel at any time.
• Press "SEND."