EPC In DRIVE MODE: Notes

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 firmer shift. Firmer shifts would indicate that the EPC pressure control is working 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 is working 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 values.
• 00 - sets EPC pressure to 00 kPa (00 psi).
• 15 - sets EPC pressure to 103 kPa (15 psi).
• 30 - sets EPC pressure to 206 kPa (30 psi).
• 45 - sets EPC pressure to 310 kPa (45 psi).
• 60 - sets EPC pressure to 411 kPa (60 psi).
• 75 - sets EPC pressure to 517 kPa (75 psi).
• 90 - sets EPC pressure to 620 kPa (90 psi).

OSC "EPC" DRIVE MODE operates ONLY when:

• the digital TR sensor is operational and no digital TR sensor DTCs are present.
• the vehicle speed sensor is operational and no VSS sensor DTCs are present.
• the transmission range selector lever is in O/D.
• the pressure gauge is installed.
• the key is ON.
• the engine is ON.
• the vehicle speed is greater than 3.2 km/h (2 mph).
• the OSC value for EPC must be greater than what the PCM commands (see EPC PID).

OSC Command Values

• 00 - sets EPC pressure to 00 kPa (00 psi).
• 15 - sets EPC pressure to 103 kPa (15 psi).
• 30 - sets EPC pressure to 206 kPa (30 psi).
• 45 - sets EPC pressure to 310 kPa (45 psi).
• 60 - sets EPC pressure to 411 kPa (60 psi).
• 75 - sets EPC pressure to 517 kPa (75 psi).
• 90 - sets EPC pressure to 620 kPa (90 psi).
• 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 "0-620 kPa (0-90 psi)."
• Press "SEND" to send command.
• Re-Select Value "0-620 kPa (0-90 psi)."
• Press "SEND" to send command.
• Select "XXX" to cancel at any time.
• Press "SEND."