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Scan Tool Testing and Procedures

Output State Control (OSC) Mode

Output state control (OSC) allows the technician to take control of certain parameters to function the transmission. For example, OSC allows the technician to shift the transmission only when commanding a gear change. If the technician commands first gear in OSC, the transmission will remain in first gear until the technician commands the next gear. For another example, the technician can command a shift solenoid to turn on or off when carrying out an electrical circuit check. OSC has 2 modes of operation for transmission, the BENCH MODE and the DRIVE MODE. Each mode/parameter 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 vehicle speed sensor (VSS) must be operational. No diagnostic trouble codes (DTCs) related to the digital TR sensor or the VSS can be present.

^ The vehicle requirements MUST BE MET when SENDING the OSC value. Refer to vehicle requirements for each individual test.
^ If the vehicle requirements are NOT MET when SENDING the OSC value, an ERROR MESSAGE will appear. When the ERROR MESSAGE is received, OSC is aborted and must be restarted.
^ If after a sent value is substituted and the vehicle requirements are no longer met, the PCM will cancel the OSC value and resume normal operation. No error message will be sent.
^ The OSC value XXX may be sent anytime to cancel OSC.

Output State Control (OSC) Procedures
^ Carry out visual inspection and vehicle preparation as necessary.
^ Select Vehicle and Engine Selection menu.
^ Select appropriate vehicle and engine.
^ Select Diagnostic Data Link.
^ Select Powertrain Control Module.
^ Select Diagnostic Test Mode.
^ Select KOEO On-Demand Self Test and KOER On-Demand Self Tests.
^ Carry out test and record DTCs.
^ Repair all NON-Transmission DTCs.
^ Repair all VSS and digital TR sensor DTCs.
^ Make sure that VSS and digital TR sensors are functional.
^ Select Active Command Modes.
^ Select Output State Control.
^ Select Trans - Bench Mode or Trans - Drive Mode.

OSC Transmission Bench Modes
The following Transmission Bench Modes may be used as necessary during diagnostics.

SSA, SSB, SSC, SSD and TCC in BENCH MODE

CAUTION: The parking brake must be set prior to carrying out this procedure.

The BENCH MODE allows the technician to carry out electrical circuit checks on the following components:
^ SSA - Activates SS A OFF or ON.
^ SSB - Activates SS B OFF or ON.
^ SSC - Activates SS C OFF or ON.
^ SSD - Activates SS D OFF or ON.
^ TCC - Activates TCC OFF or ON.

OSC SSA, SSB, SSC, SSD, TCC BENCH MODE operates ONLY when:
^ VSS and digital TR sensor are operational.
^ No VSS and digital TR sensor DTCs.
^ Transmission range selector lever in P or N.
^ Key ON.
^ Engine OFF.

OSC Command Values
^ OFF - turns solenoid OFF.
^ ON - turns solenoid ON.
^ XXX - cancels OSC value sent.
^ SEND - sends the values to PCM.

BENCH MODE Procedure for SSA, SSB, SSC, SSD and TCC
Follow operating instructions from the NGS menu screen:
^ Select Output State Control .
^ Select Trans - Bench Mode .
^ Select PIDs to be monitored.
^ Monitor all selected PIDs during test.
^ Select Parameters - SSA, SSB, SSC, SSD or 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 .

PCA, PCB, PCC in BENCH MODE

CAUTION: The parking brake must be set prior to carrying out this procedure.

The BENCH MODE is also used to test the functionality of the transmission electronic pressure control. During BENCH MODE, the PCx solenoids can be commanded in increments of 15 psi from 0 to 90 psi and 90 to 0 psi.

The line pressure tap is used to verify output pressure from PC A or PC B 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 PC C solenoid.

The OSC functions for the parameter PCx allows the technician to choose the following options:
^ PCx - Activates PCx to selected values.
^ 00 - sets PCx pressure to 00 psi.
^ 15 - sets PCx pressure to 15 psi.
^ 30 - sets PCx pressure to 30 psi.
^ 45 - sets PCx pressure to 45 psi.
^ 60 - sets PCx pressure to 60 psi.
^ 75 - sets PCx pressure to 75 psi.
^ 90 - sets PCx pressure to 90 psi.

OSC PCx Bench Mode should ONLY be operated to check PRESSURE FUNCTIONALITY using an installed pressure gauge (300 psi) when:
^ VSS and digital TR sensor are operational.
^ No VSS and digital TR sensor DTCs.
^ Transmission range selector lever in P or N.
^ Pressure gauge installed.
^ Key ON.
^ Engine ON.
^ Engine rpm at least 1500.

OSC PCx Bench Mode should ONLY be operated to complete PCx SOLENOID CIRCUIT PINPOINT TESTS when:
^ VSS and digital TR sensor are operational.
^ No VSS and digital TR sensor DTCs are present.
^ Transmission range selector lever is in P or N.
^ Key ON.
^ Engine OFF.

OSC Command Values
^ 00 - sets PCx pressure to 00 psi.
^ 15 - sets PCx pressure to 15 psi.
^ 30 - sets PCx pressure to 30 psi.
^ 45 - sets PCx pressure to 45 psi.
^ 60 - sets PCx pressure to 60 psi.
^ 75 - sets PCx pressure to 75 psi.
^ 90 - sets PCx pressure to 90 psi.
^ XXX - cancels OSC value sent.
^ SEND - sends the values to PCM.

BENCH MODE Procedure for PCx
Following operating instructions from the NGS menu screen:
^ Select "Output State Control".
^ Select "Trans - Bench Mode".
^ Select "PIDs" to be monitored.
^ Monitor all selected PIDs during test.
^ Select "Parameters - PCx".
^ Select Value 0 - 90 psi".
^ Press "SEND" to send command.
^ Select "XXX" to cancel at any time.
^ Press "SEND".

OSC Transmission DRIVE MODES
The DRIVE MODE allows control of 3 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 (D) .
^ 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.
^ Reselect 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 (D) .
^ 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 (D) .
^ 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 .

Using Output State Control (OSC) and Accessing PIDs
To confirm that the OSC value was sent by the NGS and the PCM has accepted the OSC substitution, a corresponding PID for each OSC parameter must be monitored. Additional PIDs should be monitored to help the technician adequately diagnose the transmission.





This chart is a list of OSC parameters and their corresponding PID.

To confirm that the OSC substitution occurred, SEND the OSC value and monitor the corresponding PID value. If no ERROR MESSAGE was received and the value of the corresponding PID is the same as the value sent from OSC, then the OSC substitution was successful.