OSCGEAR in DRIVE MODE:

This OSC function is used to test the transaxle gear changes. The advantage of using OSC for changing gears is to allow the technician to easily test a specific gear and/or upshift or down shift that has been identified as the customer complaint. When using the OSC to command a shift change, the PCM should command the correct or normal pressure for that shift. The transaxle remains in the gear that OSC has commanded until OSC commands another gear or OSC is cancelled.

The OSC functions for the OSCGEAR parameter allow the technician to choose the following options:

• 1 - Directs the PCM to command first gear
• 2 - Directs the PCM to command second gear
• 3 - Directs the PCM to command third gear
• 4 - Directs the PCM to command fourth gear
• XXX - Cancels the OSC command for GEAR (returns to normal operation)

The vehicle requirements must be met when sending the OSC value for GEAR. If the vehicle requirements are not met when sending the OSC value, an ERROR MESSAGE appears. When the ERROR MESSAGE is received, OSC is aborted and must be restarted. After the OSC value for GEAR is sent, if the vehicle requirements are no longer met the ERROR MESSAGE does not appear but the OSC value is canceled by the PCM (monitoring corresponding PID). The OSC value XXX may be sent anytime to cancel OSC.

It is recommended to use the OSCTCC parameter in OSC to first turn off the converter clutch when testing the transaxle gear changes. This allows the technician to evaluate just the gear changes. If the torque converter clutch is not turned off, then the PCM may command the torque converter clutch to engage during a shift. This could make it more difficult for the technician to determine whether a bad shift is the result of the torque converter engaging or the actual gear change. The vehicle requirements for SENDING a OSCGEAR value is as follows:

• engine is running
• gear selector is in DRIVE
• vehicle speed is greater than 3 km/h (2 mph)
• vehicle speed must be lower than 48 km/h (30 mph) to command a downshift to first gear
• vehicle speed must be lower than 96 km/h (60 mph) to command a downshift to second gear
• vehicle speed must be lower than 145 km/h (90 mph) to command a downshift to third
• vehicle speed must be greater than 48 km/h (30 mph) to command an upshift to fourth gear