OSC - Transmission Drive Modes

The DRIVE MODE allows control of three transmission parameters. Each mode/parameter hits a unique set of vehicle operating requirements that the technician is required to meet before being allowed to operate OSC. The recommended procedure, when using the DRIVE MODE, is to control one parameter at a time.
The DRIVE MODE allows the technician to carry out the following functions on the transmission:
- GR_CM-allows upshifts or downshifts.
- TCC-engages or disengages the torque converter clutch.
- EPC-increases/decreases EPC pressure.

GR_CM in DRIVE MODE
This OSC function is used to test the transmission shift functions.
The OSC functions for the GR_CM parameter allows the technician to choose the following options:
- [1]-PCM selects 1st gear.
- [2]-PCM selects 2nd gear.
- [3]-PCM selects 3rd gear,
- [4]-PCM selects 4th gear.

OSC "GR_CM" Mode operates ONLY when:
- digital TR sensor is operational and no digital TR sensor DTCs present.
- vehicle speed sensor is operational and no VSS sensor DTCs present.
- engine is ON.
- TCC is OFF.
- transmission range selector lever is in O/D.
- vehicle speed is greater than 3.2 km/h (2 mph).

OSC Command Values
- [1]-PCM selects 1st gear.
- [2]-PCM selects 2nd gear.
- [3]-PCM selects 3rd gear.
- [4]-PCM selects 4th gear.
- [XXX]-cancels OSC value sent.
- [SEND]-sends the values to PCM.

DRIVE MODE Procedure for GR_CM
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-GR-CM."
- Select Value " 1-4."
- Press "SEND" to send command.
- Re-Select Value " 1-4."
- Press "SEND" to send command.
- Select "XXX" to cancel at any time.
- Press "SEND."

TCC in DRIVE MODE
This OSC function is used to test whether the torque converter clutch is engaging and disengaging correctly.
The OSC functions for the TCC parameter allows the technician to choose the following:
- TCC-activates TCC OFF and ON.
- [ON]-turns TCC solenoid ON.
- [OFF]-turns TCC solenoid OFF.

OSC "TCC OFF" DRIVE MODE operates ONLY when:
- digital TR sensor is operational and no digital TR sensor DTCs present.
- vehicle speed sensor is operational and no VSS sensor DTCs present.
- engine is ON.
- transmission range selector lever is in O/D.
- vehicle speed is greater than 3.2 km/h (2 mph).

OSC "TCC ON" DRIVE MODE operates ONLY when:
- digital TR sensor is operational and no digital TR sensor DTCs present.
- vehicle speed sensor is operational and no VSS sensor DTCs present.
- engine is ON.
- transmission range selector lever is in O/D.
- vehicle speed is greater than 3.2 km/h (2 mph).
- transmission is in 2nd gear or higher.
- TFT is between 15 and 135°C (60 and 275°F).
- brake is not applied "OFF" below 32 km/h (20 mph).
- (Not an excessive load on engine (engine lugging).

OSC Command Values
- [OFF]-turns TCC OFF.
- [ON]-turns TCC ON.
- [XXX]-cancels OSC value sent.
- [SEND]-sends the values to PCM.

Drive Mode Procedures for TCC
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-TCC. "
- Select "ON" to turn solenoid ON.
- Press "SEND" to send command ON.
- Select "OFF" to turn solenoid OFF.
- Press "SEND" to send command OFF.
- Select "XXX" to cancel at any time.
- Press "SEND."

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 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:
- digital TR sensor is operational and no digital TR sensor DTCs present.
- vehicle speed sensor is operational and no VSS sensor DTCs present.
- transmission range selector lever is in O/D.
- pressure gauge is installed.
- key is ON.
- engine is ON.
- vehicle speed is greater than 3.2 km/h (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 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."