Scan Tool Testing and Procedures

Output State Control (OSC) Mode

Output state control (OSC) mode allows the technician to take control of certain parameters to function the transmission. These parameters are called commands.

For example, OSC allows the technician to shift the transmission only when commanding a gear change. If the technician commands 1st gear in OSC, the transmission will remain in 1st gear until the technician commands the next gear.

Another example of the OSC features is that a technician can command a shift solenoid to turn ON or OFF when carrying out an electrical circuit check. OSC can be used in the service bay or while test driving the vehicle. Each command has a unique set of vehicle operating requirements that the technician must meet before being allowed to operate OSC.

NOTE: To operate OSC the digital transmission range (TR) sensor and the transmission speed sensors must be operational. No DTCs related to the digital TR sensor or the transmission speed sensors can be present.

- The vehicle requirements MUST BE MET when COMMANDING the OSC value. Refer to vehicle requirements for each individual test
- If the vehicle requirements are NOT MET when COMMANDING the OSC value, the command will be aborted
- If after a sent value is commanded and the vehicle requirements are no longer met, the PCM will cancel the OSC value and resume normal operation
- The OSC value can be cancelled at any time

OSC Procedures

- Carry out visual inspection and vehicle preparation as necessary
- Connect the scan tool
- Record all DTCs
- Repair all non-Transmission DTCs
- Repair all transmission speed sensor and digital TR sensor DTCs
- Make sure that the transmission speed sensors and digital TR sensors are functional

OSC - Service Bay

The following OSC service bay procedures may be used as necessary during diagnostics.

SSA/SS1, SSB/SS2, SSC/SS3, SSD/SS4 Commands - Service Bay

WARNING: Block all wheels, set the parking brake and firmly apply the service brake to reduce the risk of vehicle movement during this procedure. Failure to follow these instructions may result in serious personal injury.

OSC allows the technician to carry out electrical circuit checks on the following components:

- SSA/SS1 - Activates SSA OFF or ON
- SSB/SS2 - Activates SSB OFF or ON
- SSC/SS3 - Activates SSC OFF or ON
- SSD/SS4 - Activates SSD OFF or ON
- TCC - Activates TCC OFF or ON

OSC "SSA/SS1, SSB/SS2, SSC/SS3, SSD/SS4 and TCC" Commands operate ONLY when the following vehicle requirements are met:

- Transmission speed sensors and digital TR sensor are operational
- No transmission speed sensor and digital TR sensor DTCs are present
- Transmission selector lever is in P or N
- Key ON
- Engine OFF

Procedure for SSA/SS1, SSB/SS2, SSC/SS3, SSD/SS4 and TCC - Service Bay

To activate SSA/SS1, SSB/SS2, SSC/SS3, SSD/SS4 and TCC commands:

- be sure the vehicle requirements are met.
- follow operating instructions from the scan tool.
- using the scan tool, ACTIVATE the command ON or OFF.
- MONITOR the PID.

PCA, PCB, PCC in Commands - Service Bay

WARNING: Block all wheels, set the parking brake and firmly apply the service brake to reduce the risk of vehicle movement during this procedure. Failure to follow these instructions may result in serious personal injury.

OSC is also used to test the functionality of the transmission electronic pressure control. The PC solenoids can be commanded from 0 to 621 kPa (0 to 90 psi) and 621 to 0 kPa (90 to 0 psi).

The line pressure tap is used to verify output pressure from PCA or PCB by turning either one off while verifying the output from the other solenoid. The second pressure tap is used to verify the output from the PCC solenoid.

The OSC functions for the command PCA# allows the technician to choose the following options:

-PCA# - Activates PCA, PCB or PCC to the selected value between 0 to 621 kPa (0 to 90 psi)

OSC "PCA#" commands should ONLY be operated to check PRESSURE FUNCTIONALITY using an installed pressure gauge 2,068 kPa (300 psi) when the following vehicle requirements are met:

- Transmission speed sensors and digital TR sensor are operational
- No transmission speed sensor or digital TR sensor DTCs are present
- Transmission selector lever is in P or N
- Pressure gauge installed
- Key ON
- Engine ON
- Engine rpm at least 1,500

OSC "PCA#" commands should ONLY be operated to complete PCA# SOLENOID CIRCUIT PINPOINT TESTS when:

- transmission speed sensors and digital TR sensor are operational.
- no transmission speed sensor or digital TR sensor DTCs are present.
- transmission selector lever is in P or N.
- key is ON.
- engine is OFF.
- using the scan tool, ACTIVATE the PCA, PCB or PCC commands between 0 to 621 kPa (0 to 90 psi).

Procedure for PCA# - Service Bay

To activate PCA, PCB or PCC commands:

- be sure vehicle requirements are met.
- follow operating instructions from the scan tool.
- using the scan tool, ACTIVATE the command between 0 to 621 kPa (0 to 90 psi).
- monitor the selected PID.

OSC - Drive Test

The OSC Drive Test allows control of 3 transmission parameters. Each parameter has a unique set of vehicle operating requirements that the technician must meet before being allowed to operate OSC. The recommended procedure during a transmission drive test is to control one parameter at a time.

The OSC drive test 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
- HRSH_SFT - Commands a higher control pressure during upshift

The pressure control (PC) solenoids for this transmission are not directly controlled during OSC testing. Pressures may be raised during an upshift via the harsh shift control channel (HRSH_SFT).

GEAR in OSC Drive Test

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" command operates ONLY when:

- transmission speed sensors and digital TR sensor are operational.
- no transmission speed sensor and digital TR sensor DTCs are present.
- engine ON.
- TCC OFF (TCC cannot be engaged).
- transmission selector lever in (D).
- vehicle speed is greater than 3 km/h (2 mph).

Drive Test Procedure for GEAR

To activate the GEAR command:

- be sure the vehicle requirements are met.
- transmission speed sensors and digital TR sensor are operational.
- no transmission speed sensor and digital TR sensor DTCs are present.
- follow operating instructions from the scan tool.
- using the scan tool, ACTIVATE the command value "1-5".
- monitor the PID.

TCC in Drive Test

This OSC function is used to test whether the torque converter clutch (TCC) 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" Command operates ONLY when:

- transmission speed sensors and digital TR sensors are operational.
no transmission speed and digital TR sensor DTCs are present.
- engine is ON.
- transmission selector lever is in (D).
- vehicle speed is greater than 3 km/h (2 mph).

OSC "TCC ON" Command operates ONLY when:

- transmission speed sensors and digital TR sensors are operational.
- no transmission speed and digital TR sensor DTCs are present.
- engine is ON.
- transmission selector lever is in (D).
- vehicle speed is greater than 3 km/h (2 mph).
- transmission is in 2nd gear or higher.
- transmission fluid temperature (TFT) is between 33-153�C (60-275�F).
- brake is not applied (OFF) below 32 km/h (20 mph).
- maintaining a steady speed.

Drive Test Procedures for TCC

To activate the TCC command:

- be sure the vehicle requirements are met.
- follow operating instructions from the scan tool.
- using the scan tool, ACTIVATE command value ON and OFF.
- monitor the PID.

HRSH_SHFT in Drive Test

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 command test using a hydraulic pressure gauge.

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

- HRSH_SHFT - Command to activate the harsh shift command
- 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)

OSC "HRSH_SHFT" Drive Test operates ONLY when the following vehicle requirements are met:

- Transmission speed sensors and digital TR sensor are operational
- No transmission speed sensor or digital TR sensor DTCs are present
- Transmission selector lever in (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)

Drive Test Procedure for HRSH_SHFT

To ACTIVATE the HRSH_SHFT command:

- be sure the vehicle requirements are met.
- follow operating instructions from the scan tool.
- using the scan tool, ACTIVATE the command value ON and OFF.
- monitor the PID