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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 transaxle. For example, OSC allows the technician to shift the transaxle only when commanding a gear change. If the technician commands 1st gear in OSC, the transaxle will remain in 1st 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 two modes of operation for transaxle, 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 Transmission Range (TR) sensor and the Vehicle Speed Sensor (VSS) must be operational. No Diagnostic Trouble Codes (DTCs) related to the TR sensor or the VSS can be present.

NOTE: Technician should perform a key of before initiating any OSC activities in order to clear any previously learned Failure Mode Effects Management (FMEM) actions from the vehicle memory.

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 SENDING an OSC value, the vehicle requirements are no longer met, the PCM will cancel the OSC value and NO ERROR message will appear. Once the vehicle requirements are met again, the PCM will automatically SEND the previous OSC value without any additional actions required by the technician. 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-transaxle DTCs.
- Repair all VSS and TR sensor DTCs.
- Make sure that VSS/TR sensors are functional.
- Select "Active Command Modes."
- Select "Output State Control.
- Select "Trans-Bench Mode or Trans-Drive Mode."

OSC-Transaxle Bench Modes
The following Transaxle Bench Modes may be used or necessary during diagnostics.

SSA, SSB in BENCH MODE
The BENCH MODE allows the technician to carry out electrical circuit checks on the following components:
- SSA-Activates SSA OFF or ON.
- SSB-Activates SSB OFF or ON.

OSC "SSA/B" BENCH MODE operates ONLY when:
- VSS and TR sensor are operational.
- No VSS and TR sensor DTCs.
- Transaxle range selector level in P.
- Key ON.
- Engine OFF.

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

BENCH MODE Procedure for SSA, SSB:
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 (= SST, SS2).
- Select "ON" to turn solenoid ON.
- Press "SEND" to send command.
- Select "OFF" to turn solenoid OFF.
- Press "SEND" to send command.
- Select "XXX" to cancel at any time. Press "SEND."

SSC, SSD and SSE in BENCH MODE
The BENCH MODE is also used to test the functionality of pulse width modulated solenoids of the transaxle. During BENCH MODE, the SSC/D/E solenoids can ramp in increments of 25% from 0% to 100% duty cycle and 100% to 0% duty cycle. The OSC functions for the parameters SSC/D/E allow the technician to choose the following options:
- SSC-Activates SSC to selected values.
- SSD-Activates SSD to selected values.
- SSE-Activates SSE to selected values.
- 00-sets SSC/D/E duty cycle to 00%
- 25-sets SSC/D/E duty cycle to 25%
- 50-sets SSC/D/E duty cycle to 50%
- 75-sets SSC/D/E duty cycle to 75%
- 100-sets SSC/D/E duty cycle to 100%

OSC "SSC/D/E" BENCH MODE operates ONLY when:
- VSS and TR sensor are operational. - No VSS and TR sensor DTCs.
- Transaxle range selector level in P.
- Key ON.
- Engine ON.
- Engine speed at least 1,500 RPM.
- Pressure gauge installed (optional). OSC Command Values:
- 00-sets SSC/D/E duty cycle to 00%
- 25-sets SSC/D/E duty cycle to 25%
- 50-sets SSC/D/E duty cycle to 50%
- sets SSC/D/E duty cycle to 75%
- 100-sets SSC/DIE duty cycle to 100%
- XXX-cancels OSC value sent.
- SEND-sends the values to PCM.

BENCH MODE Procedure for SSC, SSD and SSE 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-SSC, SSD, SSE."
- Select Value "0-100%."
- Press "SEND" to send command.
- Select "XXX" to cancel at any time.
- Press "SEND" to send command.

PCA in BENCH MODE

NOTE: PCA, EPC and VFS all refer to the solenoids. PCA is preferred for this transmission because the diagnostic tool display PCA.

The BENCH MODE is also used to test the functionality of the transaxle electronic pressure control. During BENCH MODE, the PCA solenoid can ramp in increments of 20 PSI from 50 PSI to 150 PSI and 150 PSI to 50 PSI.

NOTE: PCA pressure represents transaxle line pressure. The technician should measure PCA pressure using the line pressure lap.

The OSC function for the parameter PCA allows the technician to choose the following options:
- EPC-Activates PCA to selected values.
- 50-sets PCA pressure to 50 PST.
- 70-sets PCA pressure to 70 PSI.
- 90-sets PCA pressure to 90 PSI.
- 110-sets PCA pressure to 110 PSI.
- 130-sets PCA pressure to 130 PSI.
- 150-sets PCA pressure to 150 PSI.

OCS PCA" BENCH MODE should ONLY be operated to check PRESSURE FUNCTIONALITY using an installed pressure gauge when:
- VSS and digital TR sensor are operational.
- No VSS and digital TR sensor are operational.
- Key ON.
- Engine ON.
- Engine speed at least 1,500 RPM.

OSC "PCA" BENCH MODE should ONLY be operated to compete PCA SOLENOID CIRCUIT PINPOINT TESTS when:
- VSS and digital TR sensor are operational.
- No VSS and digital TR sensor DTCs.
- Transmission range selector lever in P.
- Key ON.
- Engine ON.

OSC Command Values:
- 50-sets PCA pressure to 50 PSI.
- 70-sets PCA pressure to 70 PSI.
- 90-sets PCA pressure to 90 PSI.
- 110-sets PCA pressure to 110 PSI.
- 130-sets PCA pressure to 130 PSI.
- 150-sets PCA pressure to 150 PSI.
- XXX-cancels OSC sent value.
- SEND-sends the values to PCM.

BENCH MODE Procedure for PCA:
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 lest.
- Select "Parameters-PCA."
- Select Value "50-150 PSI."
- Press "SEND" to send command.
- Select "XXX" to cancel at any time
- Press "SEND" to send the command.

OSC-Transmission DRIVE MODES
The DRIVE MODE allows control of three transaxle 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 transaxle:
- GEAR-allows upshifts or downshifts.
- TCC-engages or disengages the torque converter clutch.
- FIRM_SFT-commands a higher control pressure during upshift only.

Electronic Pressure Control solenoid A (EPC) for this transaxle cannot directly be controlled during DRIVE MODE testing. Pressures may be raised during an upshift via the firm shift control function (FIRM_SFT).

GEAR in DRIVE MODE
This OSC function is used to lest the transaxle shift functions.

NOTE: When the technician commands 1st gear during OSC mode, engine braking is automatically activated for 1st gear. Be aware that normal transaxle operation does not use engine braking in 1st gear.

The OSC function for the GEAR parameter allows the technician to choose the following options:
- PCM selects first gear.
- 2-PCM selects second gear.
- 3-PCM selects third gear.
- 4-PCM selects fourth gear.

OSC "GEAR" Mode operates ONLY when:
- VSS and TR sensor are operational.
- No VSS and TR sensor DTCs.
- Engine "ON. "
- Transaxle range selector lever in O/D.
- Vehicle speed is greater than 3 km/h (2 mph).
- Gear selected is equal to or below maximum gear available (PID "GEARTOP").
- Maximum vehicle speed for downshift into first gear is 40 km/h (25 mph).
- Maximum vehicle speed for downshift into second gear is 97 km/h (60 mph).
- Maximum vehicle speed for downshift into third gear is 204 km/h (127 mph).
- Minimum vehicle speed for an upshift to fourth gear is 32 km/h (20 mph).

OSC Command Values:
- 1
- PCM selects first gear.
- 2-PCM selects second gear.
- 3-PCM selects third gear.
- 4-PCM selects fourth gear.
- XXX-cancels OSC sent value.
- 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 " 1-4."
- Press "SEND" to send command.
- Re-Select Value " 1-4."
- Press "SEND" to send command.
- Select "XXX" to cancel at any time.
- Press "SEND" to send command.

TCC in DRIVE MODE
This OSC function is used to test whether the torque converter clutch is engaging and disengaging correctly.

CAUTION: Technicians should maintain an engine speed of at least 1,500 RPM during torque converter engagement testing. Failure to maintain at least 1,500 RPM can produce severe vehicle lugging and vibrations depending upon driving/vehicle loading conditions. During output state control testing, the TCC could oscillate between engaged and disengaged mode if engine speed requirements are not followed.

The OSC function for the TCC parameter allows the technician to choose the following:
- TCC-activates TCC OFF and ON.
- ON-turns TCC ON.
- OFF-turns TCC OFF.

OSC "TCC OFF" DRIVE MODE operates ONLY when:
- VSS and TR sensors are operational.
- No VSS and TR sensor DTCs present.
- Engine ON.
- Transaxle range selector lever in O/D.
- Vehicle speed is greater than 3 km/h (2 mph).
- No transaxle gear shifts are in progress.

OSC "TCC ON" DRIVE MODE operates ONLY when:
- VSS and TR sensors are operational.
- No VSS and TR sensor DTCs present.
- Engine "ON".
- Transaxle range selector lever in O/D.
- Vehicle speed is greater than 3 km/h (2 mph).
- Transaxle in second or higher gear.
- TFT is between 16°C and 33°C (60°F and 270°F).
- Brake is "OFF" when vehicle speed is below 20 mph.
- Engine speed at least 1,500 RPM.
- Speed ratio across the converter (PID "TCCRAT") is between 0.70 and 1.0.
- No transaxle gear shifts are in progress. OSC Command Values
- OFF-Turns TCC OFF.
- ON-Turns TCC ON.
- XXX-Cancels OSC value sent.
- SEND-Sends the values to PCM.

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

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. Firmer 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 EPC solenoid test 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 firm shift channel.
- 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).

OSC "FIRM_SFT" DRIVE MODE operates ONLY when:
- VSS and TR sensor are operational.
- No VSS and TR sensor DTCs present.
- Transaxle range selector lever in O/D.
- Engine "ON."
- Key"ON."
- Vehicle speed greater than 2 mph.

TCC cannot be forced ON using NGS OSC mode (PID "OSC TCC" not equal to ON)

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."
- Select "ON" to turn Firm Shift Mode ON.
- Select "SEND" to send command.
- Select "OFF" to turn Firm Shift Mode OFF.
- Select "SEND" to send command. Select "XXX" to cancel at any time.
- Select "SEND" to send command.

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 or PIDs for each OSC parameter should be monitored. Additional PIDs should be monitored to help the technician adequately diagnose the transaxle.








The following is a list of OSC parameters and their corresponding PIDs:

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.

The following general PID list may be of use to the technician when exercising OSC.