Electrical System
GENERAL INFORMATIONThe following instructions outline the use of the NGS Tester to operate the electrical portion of the transmission independently of vehicle electronics to allow the technician to determine transmission concerns. For instructions on hooking-up the NGS tester, refer to On-Board Diagnosis System.
OUTPUT TEST MODE
This diagnostic test mode aids in servicing output actuators associated with the PCM system. It allows the technician to energize and de-energize most of the system output actuators on command.
PERFORMING OUTPUT TEST MODE
Enter Output Test Mode with key ON, engine OFF.
Using The NGS Tester:
1. Select VEHICLE AND ENGINE SELECTION.
2. Select proper model year, engine, model, if necessary.
3. Select DIAGNOSTIC DATA LINK.
4. Select DIAGNOSTIC TEST MODE.
5. Enter ACTIVE COMMANDS.
6. Enter OUTPUT TEST MODE
OUTPUT STATE CONTROL
Output State Control (OSC) is a new feature on the NGS. OSC control allows you to function the main components of the 5R55E quickly and easily, and to provide accurate information to properly diagnose the transmission.
PERFORMING OUTPUT STATE CONTROL
Enter Output State Control with key ON, engine OFF.
Using the NGS Tester:
1. Select VEHICLE AND ENGINE SELECTION.
2. Select proper model year, engine, model, if necessary.
3. Select DIAGNOSTIC DATA LINK.
4. Select DIAGNOSTIC TEST MODE.
5. Enter ACTIVE COMMANDS.
6. Enter OUTPUT STATE CONTROL.
OSC allows the technician control of certain parameters to function the transmission and transmission shifting only when commanded by the technician.
^ If first gear is commanded, the transmission will remain in first gear until the next gear is commanded.
^ OSC control is the technician commanding a shift solenoid to turn ON or OFF when performing an electrical circuit check.
OSC has two modes of operation for transmission:
^ BENCH MODE
^ DRIVE MODE
NOTE: To operate OSC, the Transmission Range (TR) Sensor and the Vehicle Speed Sensor (VSS) must be operational. No DTCs related to the TR sensor or the VSS can be present.
OSC-TRANSMISSION BENCH MODE
Highlight TRANS-BENCH MODE and press trigger. BENCH MODE is functional ONLY when the vehicle gear selector is in Park or Neutral. Depending on the test, BENCH MODE may be used in either Key ON Engine Off (KOEO) or Key On Engine Running (KOER). BENCH MODE allows the technician to function the following components.
^ Shift Solenoid 1 (SS1)-commands the PCM to turn SS1 ON or OFF.
^ Shift Solenoid 2 (SS2)-commands the PCM to turn SS2 ON or OFF.
^ Shift Solenoid 3 (SS3)-commands the PCM to turn SS3 ON or OFF.
^ Shift Solenoid 4 (SS4)-commands the PCM to turn the Pulse Width Modulated (PWM) SS4 ON or OFF.
^ Torque Converter Clutch (TCC)-commands the PCM to turn the TCC solenoid ON or OFF.
^ Electronic Pressure Control (EPC)-commands the PCM to control the EPC solenoid to obtain commanded pressure.
SST, SS2, SS3, SS4, AND TCC IN BENCH MODE:
These OSC functions are used to turn solenoids OFF and ON when performing an electrical circuit check. The options available for these solenoids are.:
^ OFF-Commands PCM to turn solenoid OFF
^ ON-Commands PCM to turn solenoid ON
^ XXX-Cancels OSC for that particular parameter
^ SEND-Sends the values to the PCM
Vehicle requirements for sending an OSC value for SS1 SS2, SS3, SS4 and TCC in BENCH MODE are:
^ Key On Engine Off (KOEO) (engine not running).
^ Transmission Range Selector Lever in PARK.
NOTE: If an OSC command is sent and the requirements are not met, the PCM will abort the function, and "kick out" of the OSC mode.
If 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. The OSC value (XXX) may be sent at anytime to cancel OSC.
EPC IN BENCH MODE:
BENCH MODE is used to test the functionality of the transmission's Electronic Pressure Control (EPC).
In BENCH MODE, the EPC solenoid can be commanded to increase or decrease pressure from 0 to 90 psi in increments of 15 psi. To command the EPC solenoid, select EPC, then select the appropriate value and press SEND to send command.
To operate EPC in BENCH MODE, attach a hydraulic pressure gauge to the line pressure tap. The pressure gauge is required to verify the EPC solenoid and its associated mechanical and hydraulic components are working correctly.
^ 0-commands PCM to control EPC pressure to 0 psi.
^ 15-commands PCM to control EPC pressure to 15 psi.
^ 30-commands PCM to control EPC pressure to 30 psi.
^ 45-commands PCM to control EPC pressure to 45 psi.
^ 60-commands PCM to control EPC pressure to 60 psi.
^ 75-commands PCM to control EPC pressure to 75 psi. 90-commands PCM to control EPC pressure to 90 psi.
^ XXX-cancels OSC for EPC.
NOTE: If an OSC command is sent and the requirements are not met, the PCM will abort the function, and "kick out" of the OSC mode.
If vehicle requirements are not met when sending the OCS 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, 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 at any time to cancel OSC.
OSC-TRANSMISSION DRIVE MODE
Highlight DRIVE MODE and press trigger.
DRIVE MODE allows control of three transmission parameters. Each parameter has a unique set of vehicle operating requirements that the technician is required to meet before operating OSC. The recommended procedure, when using the DRIVE MODE, is to control one parameter at a time.
DRIVE MODE allows the technician to perform the following functions on the transmission.
^ GR-CM-commands the PCM to upshift or downshift.
^ TCC-commands the PCM to engage or disengage the torque converter clutch.
^ EPC-commands the PCM to increase or decrease EPC pressure.
GR-CM in DRIVE MODE:
The advantage of using the OSC for changing gears is to allow the technician to exactly duplicate the vehicle condition.
For example, it the customer concern is a 3-4 shift up a steep grade, the technician can drive the vehicle up a steep grade and command a 3-4, 4-3 shift over and over again. Also, during the shift change, the EPC pressure is the exact pressure that the vehicle normally produces.
The OSC functions for the OR-CM parameter allows the technician the following options:
^ (1)-PCM commands 1st gear
^ (2)-PCM commands 2nd gear
^ (3)-PCM commands 3rd gear
^ (4)-PCM commands 4th gear
^ (5)-PCM commands 5th gear
^ (XXX)-cancels OSC for OR-CM
^ (SEND)-sends the values to the PCM
NOTE: If an OSC command is sent and the requirements are not met, the PCM will abort the function, and "kick out" of the OSC mode.
If vehicle requirements are not met when sending the OCS 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. The OSC value (XXX) may be sent at any time to cancel the OSC.
It is recommended to use the TCC parameter in OSC to first turn OFF the torque converter clutch before testing transmission shift functions. This will allow the technician to evaluate only the gear changes. If the TCC is not turned off, the PCM may command converter clutch engagement during a shift. This will make it difficult to tell whether a shift concern is the result of the converter clutch operation or of the gear change itself.
The vehicle requirements for sending a OR-CM value are:
^ engine running.
^ transmission range selector in Overdrive position.
^ vehicle speed greater than 2 mph.
^ TCC is OFF.
TCC in DRIVE MODE:
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 allow the technician to choose the following:
^ (ON)-turns TCC solenoid ON to engage the converter clutch.
^ (OFF)-turns TCC solenoid OFF to disengage the converter clutch.
^ (XXX) -cancels the OSC for TCC.
^ (SEND)-sends the values to the PCM.
NOTE: If an OSC command is sent and the requirements are not met, the PCM will abort the function, and "kick out" of the OSC mode.
If vehicle requirements are not met when sending the OCS value, an ERROR message will appear.
When the ERROR message is received, the 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.
The OSC value (XXX) may be sent at any time to cancel the OSC.
The vehicle requirements for sending the TCC value (OFF) are:
^ engine running.
^ transmission range selector in Overdrive position.
^ vehicle speed greater than 2 mph.
The vehicle requirements for sending the TCC value (ON) are:
^ engine running.
^ transmission range selector in the Overdrive position.
^ vehicle speed is greater than 2 mph transmission in 2nd gear or higher transmission fluid temperature (TFT) is between 60 and 275:F brake is not applied "off" when the vehicle is below 20 mph.
^ no excessive load on engine (engine lugging).
EPC IN DRIVE MODE:
This OSC function is used to increase the EPC pressure while testing the transmission gear changes.
The EPC in DRIVE MODE function 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 be harsher than normal. The harsher shifts would indicate that EPC pressure control is working at higher pressures.
The best test for the EPC is to use BENCH MODE and a hydraulic pressure gauge. Using the EPC in BENCH MODE will confirm that the EPC works at both higher and lower pressures.
The OSC functions for EPC allows changes from 0 to 90 psi in 15 psi increments.
^ 0-commands PCM to control EPC pressure to 0 psi.
^ 15-commands PCM to control EPC pressure to 15 psi.
^ 30-commands PCM to control EPC pressure to 30 psi.
^ 45-commands PCM to control EPC pressure to 45 psi.
^ 60-commands PCM to control EPC pressure to 60 psi.
^ 75-commands PCM to control EPC pressure to 75 psi.
^ 90-commands PCM to control EPC pressure to 90 psi.
^ XXX-cancels OSC for EPC.
^ SEND-sends the values to the PCM.
The vehicle requirements for sending an OSC value for EPC in DRIVE MODE are:
^ engine running.
^ transmission range selector in Overdrive position.
^ vehicle speed greater than 2 mph.
^ OSC value for EPC must be greater than what the PCM commands (see EPC PID)
NOTE: If an OSC command is sent and the requirements are not met, the PCM will abort the function, and "kick out" of the OSC mode.
If vehicle requirements are not met when sending the OCS value, an ERROR message will appear.
When the ERROR message is received, the 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.
The OSC value (XXX) may be sent at anytime to cancel OSC.
LINKING OSC AND PIDS
To confirm the OSC value was sent by the OSC and the PCM has accepted the OSC substitution, the PIDs function must be linked to the OSC function so that the parameters can be monitored.
To link the OSC and PID functions, press the PID (button 7) at the bottom of the screen.
The PIDs selection screen will appear. Highlight the PIDs you wish to select and press the trigger. An asterisk will appear next to the PIDs you select.
After selecting the desired PIDs press START (button 7) and return to the OSC screen. The following 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 remains the same as the value sent from the OSC, then the OSC substitution was successful.