OSC-Transmission Drive Modes
The DRIVE MODE allows control of three transmission parameters. Each mode/parameter has a unique set of vehicle operating requirements that the technician must 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:
- GEAR - allows upshifts or downshifts.
- TCC - engages or disengages the torque converter clutch.
- FIRM_SFT - Commands a higher control pressure during upshift.
The Pressure Control (PCx) solenoids for this transmission are not directly controlled during DRIVE MODE testing. Pressures may be raised during an upshift via the harsh shift control channel (FIRM_SFT)
GEAR in DRIVE MODE
This OSC function is used to test the transmission shift functions.
The OSC functions for the GEAR parameter allow 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.
- [5]-PCM selects 5th gear.
OSC "GEAR" Mode operates ONLY when:
- VSS and digital TR sensor are operational.
- No VSS and digital TR sensor DTCs.
- Engine ON.
- TCC "OFF" (TCC cannot be engaged)
- Transmission range selector lever in D5.
- Vehicle speed is greater than 3 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.
- [5]-PCM selects 5th gear.
- [XXX]-cancels OSC value sent.
- [SEND]-sends the values to PCM.
DRIVE MODE Procedure for GEAR
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 - GEAR."
- Select Value " 1-5."
- Press "SEND" to send command.
- Re-Select Value " 1-5."
- 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:
- VSS and digital TR sensors are operational.
- No VSS and digital TR sensor DTCs present.
- Engine ON.
- Transmission range selector lever in D5.
- Vehicle speed is greater than 3 km/h (2 mph).
OSC "TCC ON" DRIVE MODE operates ONLY when:
- VSS and digital TR sensors are operational.
- No VSS and digital TR sensor DTCs present.
- Engine ON.
- Transmission range selector lever in D5.
- Vehicle speed is greater than 3 km/h (2 mph).
- Transmission in 2nd gear or higher.
- TFT is between 33 - 153°C (60 - 275°F).
- Brake not applied "OFF" below 32 km/h (20 mph).
- Maintain steady speed.
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 NGS 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."
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."