With Manufacturer's Scan Tool (NGS Tester)

DIAGNOSTICS
Diagnosing an electronically controlled automatic transmission is simplified by using the following procedures. One of the most important things to remember is that there is a definite procedure to follow. DO NOT TAKE SHORT CUTS OR ASSUME THAT CRITICAL CHECKS OR ADJUSTMENTS HAVE ALREADY BEEN MADE. Follow the procedures as written to avoid missing critical components or steps. By following the diagnostic sequence, the technician will be able to diagnose and repair the concern the first time.


ON-BOARD DIAGNOSTICS WITH NGS

NOTE: These quick tests should be used to diagnose the powertrain control and should be performed in order.
- Quick Test 1.0-Visual Inspection
- Quick Test 2.0-Set Up
- Quick Test 3.0-Key On, Engine Off (KOEO)
- Quick Test 4.0-Continuous Memory
- Quick Test 5.0-Key On, Engine Running (KOER)
- Special Test Mode
- Wiggle Test
- Output Test Mode
- PCM Reset Mode
- Clearing DTCs
- OBD II Drive Cycle
- Other NGS Features

Other diagnostic methods include the following:
- Parameter Identification (PID) Access Mode
- Freeze Frame Data Access Mode
- Oxygen Sensor Monitor Mode


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 1st gear in OSC, the transmission will remain in 1st gear until the technician commands the next gear. Another example, the technician can command a shift solenoid to turn on or off when performing an electrical circuit check. OSC has two 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 is required to 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 individual test modes for vehicle requirement.
- If the vehicle requirements are NOT MET when SENDING the OSC value, and ERROR MESSAGE will appear. When the ERROR MESSAGE is received, OSC is aborted and must be restarted.
- If AFTER SENDING an OSC value, and the vehicle requirements are no longer met, the PCM will cancel the OSC value and NO ERROR message will appear.
- The OSC value [XXX] may be sent anytime to cancel OSC.


OUTPUT STATE CONTROL (OSC) PROCEDURES:
- Perform visual inspection and vehicle preparation as required.
- 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."
- Perform test and record DTCs.
- Repair all NON-transmission DTCs.
- Repair all VSS and digital TR sensor DTCs.
- Ensure that VSS/digital TR sensors are functional.
- Select "Active Command Modes."
- Select "Trans-Bench Mode" or "Trans-Drive Mode."


OSC-TRANSMISSION BENCH MODES
The following Transmission Bench Modes may be used or required during diagnostics.


SSA, SSB AND TCC IN BENCH MODE:
The BENCH MODE allows the technician to perform electrical circuit checks on the following components:
- SSA-Activates SS#1 OFF or ON.
- SSB-Activates SS#2 OFF or ON.
- TCC-Activates TCC OFF or ON.

OSC -SSA, SSB, 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.
- 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 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 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."


EPC IN BENCH MODE:
The BENCH MODE is also used to test the functionality of the transmission's electronic pressure control. During BENCH MODE, the EPC solenoid can ramp in increments of 15 PSI from zero to 90 PSI and 90 to zero PSI.

The OSC functions for the parameter EPC allows the technician to choose the following options:
- EPC-Activates EPC to selected values.
- [00]-sets EPC pressure to 00 kPa (00 PSI).
- [15]-sets EPC pressure to 103 kPa (15 PSI).
- [30]-sets EPC pressure to 206 kPa (30 PSI).
- [45]-sets EPC pressure to 310 kPa (45 PSI).
- [60]-sets EPC pressure to 411 kPa (60 PSI).
- [75]-sets EPC pressure to 517 kPa (75 PSI).
- [90]-sets EPC pressure to 620 kPa (90 PSI).

OSC -EPC- 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.
- Pressure gauge installed.
- Key ON.
- Engine on.
- Engine rpm at 1500.

OSC Command Values
- [00]-sets EPC pressure to 00 kPa (00 PSI).
- [15]-sets EPC pressure to 103 kPa (15 PSI).
- [30]-sets EPC pressure to 206 kPa (30 PSI).
- [45]-sets EPC pressure to 310 kPa (45 PSI).
- [60]-sets EPC pressure to 411 kPa (60 PSI).
- [75]-sets EPC pressure to 517 kPa (75 PSI).
- [90]-sets EPC pressure to 620 kPa (90 PSI).
- [OFF]-turns solenoid off.
- [ON]-turns solenoid on.
- [XXX]-cancels OSC value sent.
- [SEND]-sends the values to.


BENCH MODE PROCEDURE FOR EPC
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-EPC. "
- Select Value -0-620 kPa (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 three transmission parameters. Each mode/parameter has a unique set of vehicle operating requirements that the technician is required to 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 perform the following functions on the transmission:
- GR_CM-allows upshifts or downshifts.
- TCC-engages or disengages the torque converter clutch.
- EPC-increases/decreases EPC pressure.


GR_CM IN DRIVE MODE
This OSC function is used to test the transmission shift functions. The OSC functions for the GR_CM parameter allows 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-GR_CM- Mode Operates ONLY when:
- VSS and digital TR Sensor are operational.
- No VSS and digital TR Sensor DTCs.
- Engine "ON."
- TCC "OFF."
- Transmission range selector lever in O/D.
- Vehicle speed is greater than 2 mph.

OSC Command Values
- [I]-PCM selects 1st gear.
- [2]-PCM selects 2nd gear.
- [3]-PCM selects 3rd gear.
- [4]-PCM selects 4th gear.
- [5]-PCM selects 5th gear.
- [OFF]-turns solenoid off.
- [ON]-turns solenoid on.
- [XXX]-cancels OSC value sent.
- [SEND]-sends the values to.


DRIVE MODE PROCEDURE FOR GR_CM
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-GR_CM.
- 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 O/D.
- Vehicle speed is greater than 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 O/D.
- Vehicle speed is greater than 3.2 km/h (2 mph).
- Transmission in 2nd gear or higher.
- TFT is between 15°-135°C (60°-275°F).
- Brake not applied "OFF" below 32 km/h (20 mph).
- (Not an excessive load on engine (engine lugging).

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."


EPC IN DRIVE MODE
This OSC functions is used to increase the EPC pressure while testing the transmission shift functions. This OSC functions can only increase the EPC pressure greater than what the PCM normally commands. If an OSC value, such as [75] or [90] PSI is sent, the upshifts and downshifts should exhibit a harsher shift. Harsher shifts would indicate that the EPC pressure control works at higher pressures. The best test for the EPC is to use the BENCH MODE and a hydraulic pressure gauge. Using EPC in the BENCH MODE will confirm that the EPC works at both the higher and lower pressures. The OSC functions for the parameter EPC allows the technician to choose the following options:

- EPC-Activates EPC to selected
- [00]-sets EPC pressure to 00 kPa (00 PSI).
- [15]-sets EPC pressure to 103 kPa (15 PSI).
- [30]-sets EPC pressure to 206 kPa (30 PSI).
- [45]-sets EPC pressure to 310 kPa (45 PSI).
- [60]-sets EPC pressure to 411 kPa (60 PSI).
- [75]-sets EPC pressure to 517 kPa (75 PSI).
- [90]-sets EPC pressure to 620 kPa (90 PSI).

OSC -EPC- 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.
- Key ON.
- Engine ON.
- Vehicle speed greater than 2 mph.
- OSC value for EPC must be greater than what the PCM commands (see EPC PID).

OSC Command Values
- [00]-sets EPC pressure to 00 kPa (00 PSI).
- [15]-sets EPC pressure to 103 kPa (15 PSI).
- [30]-sets EPC pressure to 206 kPa (30 PSI).
- [45]-sets EPC pressure to 310 kPa (45 PSI).
- [60]-sets EPC pressure to 411 kPa (60 PSI).
- [75]-sets EPC pressure to 517 kPa (75 PSI).
- [90]-sets EPC pressure to 620 kPa (90 PSI).
- [OFF]-turns solenoid off.
- [ON]-turns solenoid on.
- [XXX]-cancels OSC value sent.
- [SEND]-sends the values to PCM.

DRIVE MODE Procedure for EPC.
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-EPC. "
- Select Value -0-620 kPa (0-90 psi)."
- Press "SEND" to send command.
- Re-Select Value " 0-620 kPa (0-90 psi)."
- Press "SEND" to send command.
- Select "XXX" to cancel at any time.
- Press "SEND."

USING OUTPUT STATE CONTROL (OSC) AND ACCESSING PIDS

Part 1 Of 2:

Part 2 Of 2:

To confirm that the OSC value was sent by the NGS and the EEC 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. The 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 remains the same as the value sent from OSC, then the OSC substitution was successful.