NAG1 Automatic Transmission - Electrical Diagnostics: Wiring

Additional Wiring

For complete wiring diagrams, refer to SYSTEM WIRING DIAGRAMS .

The Transmission Control Module (TCM) receives information from the Engine, Anti-lock Brake System, and the Electronic Gear Shift control modules over the CAN C bus. The CAN C bus is a high speed communication bus that allows real time control capability between various controllers. Most messages are sent every 20 msec, this means critical information can be shared between multiple controllers almost instantaneously. The CAN C bus is a two wire bus with a CAN (+) and a CAN (-) circuit. To reduce the potential of radio and other electrical noise interference, the CAN Bus circuit wiring is manufactured using a twisted pair configuration within the electrical wiring harness.

For complete wiring diagrams, refer to SYSTEM WIRING DIAGRAMS .

The Transmission Control Module (TCM) monitors ignition voltage. The DTC will set if the monitored battery voltage drops below 8.5 volts and a temporary limp in will be activated. If the voltage rises above 9.0 volts, normal operations is resumed and the TCM will record the DTC as a one trip fault. The DTC will only mature to a full DTC if the voltage is less than 8.5 volts with an engine speed greater than 2000 RPM for a least 60 seconds.

For complete wiring diagrams, refer to SYSTEM WIRING DIAGRAMS .

The Transmission Control Module (TCM) monitors ignition voltage. The DTC will set and temporary limp-in will be activated, if the monitored battery voltage rises above 16.9 volts. If the voltage drops below 16.4 volts, normal operations is resumed and the TCM will record the DTC as a one trip fault. The DTC will only mature to a full DTC if the voltage rises above 16.9 volts with an engine speed greater than 2000 RPM for a least 60 seconds.

For complete wiring diagrams, refer to SYSTEM WIRING DIAGRAMS .

The Transmission Control Module (TCM) performs various internal tests to verify proper controller operation. If the TCM detects that the variables that dictate the vehicle application are not present a DTC will set.

For complete wiring diagrams, refer to SYSTEM WIRING DIAGRAMS .

The Transmission Control Module (TCM) performs various internal tests to verify proper controller operation. If the TCM detects an error with the controllers Random Access Memory (RAM), the controller will enter Limp-in mode and illuminate the MIL.

For complete wiring diagrams, refer to SYSTEM WIRING DIAGRAMS .

The Transmission Control Module (TCM) performs various internal tests to verify proper controller operation. If the TCM detects an error with the controllers Read Only Memory (ROM), the controller will enter Limp-in mode and illuminate the MIL.

For complete wiring diagrams, refer to SYSTEM WIRING DIAGRAMS .

The Transmission Control Module (TCM) performs various internal tests to verify proper controller operation. If the TCM detects an error with the controllers processor, the controller will enter Limp-in mode and illuminate the MIL.

For complete wiring diagrams, refer to SYSTEM WIRING DIAGRAMS .

The Sensor Supply Voltage circuit supplies a 6-volt power supply to the two input speed sensors. The Sensor Supply Voltage circuit is constantly monitored for correct voltage between 4.8 to 7.2 volts. If the voltage does not stay within the 4.8 to 7.2 volt range, the appropriate DTC will set.

For complete wiring diagrams, refer to SYSTEM WIRING DIAGRAMS .

The Sensor Supply Voltage circuit supplies a 6 volt power supply for the two input speed sensors. The Sensor Supply Voltage circuit is constantly monitored for correct voltage between 4.8 to 7.2 volts. If the voltage does not stay within the 4.8 to 7.2 volt range, the appropriate DTC will set.

For complete wiring diagrams, refer to SYSTEM WIRING DIAGRAMS .

The Solenoid Supply Voltage output of the Transmission Control Module (TCM) provides the voltage to the three shift, two pressure and TCC solenoids. The output is active whenever the system is in normal operation. If a major system fault is detected, this output is turned off to ensure that no solenoids are active.

For complete wiring diagrams, refer to SYSTEM WIRING DIAGRAMS .

The Electrohydraulic Control Unit Assembly of the NAG1 transmission contains a temperature sensor to monitor the transmission oil temperature. This sensor is wired in series with the transmission Park/Neutral switch. The Transmission Control Module (TCM) expects to see a valid voltage level from the sensor when the shifter is in Reverse or any forward Drive position. The TCM also expects to see an open circuit condition when the shifter is in the Park or Neutral position. When the controller detects an open circuit when in Reverse or any forward drive position the DTC will set. Note: Due to an open circuit condition in Park or Neutral, the TCM substitutes the Transmission Temperature reading with Engine Temperature when in Park or Neutral

For complete wiring diagrams, refer to SYSTEM WIRING DIAGRAMS .

The Electrohydraulic Control Unit Assembly of the NAG1 transmission contains a temperature sensor to monitor the transmission oil temperature. This sensor is wired in series with the transmission Park/Neutral switch. The Transmission Control Module (TCM) expects to see a valid voltage level from the sensor when the shifter is in Reverse or any forward Drive position. The TCM also expects to see an open circuit condition when the shifter is in the Park or Neutral position. When the controller detects an open circuit when in Reverse or any forward drive position the DTC will set. Note: The TCM substitutes the Transmission Temperature reading with Engine Temperature due to an open circuit condition in Park or Neutral.

For complete wiring diagrams, refer to SYSTEM WIRING DIAGRAMS .

The Electrohydraulic Control Unit Assembly of the NAG1 transmission contains a temperature sensor to monitor the transmission oil temperature. This sensor is wired in series with the transmission Park/Neutral switch. The Transmission Control Module (TCM) expects to see a valid voltage level from the sensor when the shifter is in Reverse or any forward Drive position. The TCM also expects to see an open circuit condition when the shifter is in the Park or Neutral position. When the controller detects an open circuit when in Reverse or any forward drive position the DTC will set. Note: The TCM substitutes the Transmission Temperature reading with Engine Temperature due to an open circuit condition in Park or Neutral.

For complete wiring diagrams, refer to SYSTEM WIRING DIAGRAMS .

The Input Speed Sensor 1 (N2) is one of two hall effect speed sensors that are used by the Transmission Control Module (TCM) to calculate the transmissions turbine speed. Since the turbine speed could not be measured directly, two of the drive elements are measured. Two input speed sensors are required because both elements are not active in all gears.

For complete wiring diagrams, refer to SYSTEM WIRING DIAGRAMS .

The Transmission Control Module (TCM) constantly calculates the transmission ratio based on the input speed sensor 1 and 2 (N2-N3) signals and the calculated output shaft speed. The intent of this diagnostic is to detect if the transmission is trying to mechanically shift into a different gear than the TCM intends.

Note. The transmission control module is programmed to immediately place the transmission into neutral if P0730 or P1731 codes are set. These codes indicate that the transmission experienced an unknown or incorrect gear ratio. Placing the transmission in neutral prevents potential catastrophic failure. When this occurs, the transmission will remain in neutral until the vehicle slows to 29 Km/h (18 mph).

For complete wiring diagrams, refer to SYSTEM WIRING DIAGRAMS .

The Transmission Control Module (TCM) constantly monitors the amount of torque converter slippage. When the Torque Converter Clutch (TCC) is closed the slippage is expected to be below a predetermined threshold. If the slippage is more then expected when the TCC is closed, the DTC will set.

For complete wiring diagrams, refer to SYSTEM WIRING DIAGRAMS .

The Transmission Control Module (TCM) constantly monitors the amount of torque converter slippage. When the Torque Converter Clutch (TCC) is open the slippage is expected to be above a threshold. If the slippage is less then expected when the TCC is open, the TCM assumes that the TCC is stuck on.

For complete wiring diagrams, refer to SYSTEM WIRING DIAGRAMS .

The TCC Solenoid is activated when the Transmission Control Module (TCM) determines that the Torque Converter Clutch should be activated. The Torque Converter Clutch is a variable slip torque clutch that allows control of the slip from 5.5% to 95.5% of lock-up. The Clutch is controlled by the TCC Solenoid which is pulse width modulated (PWM) to provide the desired amount of slip. The clutch requires both an electrical PWM of 1000Hz and an hydraulic PWM of 100Hz.

For complete wiring diagrams, refer to SYSTEM WIRING DIAGRAMS .

The Modulating Pressure Control Solenoid Valve's purpose is to control the modulating pressure depending on the continuously changing operating conditions, such as load and gear change.

The Modulating Pressure Control Solenoid Valve is always active. The solenoid uses pulse width modulation (PWM) to control the transmissions hydraulic fluid pressure that is determined by the Transmission Control Module (TCM).

For complete wiring diagrams, refer to SYSTEM WIRING DIAGRAMS .

The 1-2/4-5 Solenoid is activated when the Transmission Control Module (TCM) determines that the transmission must shift into or out of second or fifth gear. The solenoid is only activated during the actual shift of the transmission. When the solenoid is activated, hydraulic pressure is applied to the proper shift elements in the transmission to allow the desired shift. Once the shift is completed the solenoid is turned off.

For complete wiring diagrams, refer to SYSTEM WIRING DIAGRAMS .

The 2-3 Solenoid is activated when the Transmission Control Module (TCM) determines that the transmission must shift into or out of 3rd gear. The solenoid is only activated during the shifting of the transmission. When the solenoid is activated, hydraulic pressure is applied to the proper shift elements in the transmission to allow the desired shift. Once the shift is completed the solenoid is turned off.

For complete wiring diagrams, refer to SYSTEM WIRING DIAGRAMS .

The 3-4 Solenoid is activated when the Transmission Control Module (TCM) determines that the transmission must shift into or out of 4th gear. The solenoid is only activated during the shifting of the transmission. When the solenoid is activated, hydraulic pressure is applied to the proper shift elements in the transmission to allow the desired shift. Once the shift is completed the solenoid is turned off.

For complete wiring diagrams, refer to SYSTEM WIRING DIAGRAMS .

The Shift Pressure Solenoid is activated when the Transmission Control Module (TCM) determines that a transmission gear shift is required. The Shift Pressure Solenoid is pulse width modulated (PWM) controlled to allow the proper amount of hydraulic pressure to the shift elements. The Shift Pressure Solenoid is only activated during the shift of the transmission. When the Shift Pressure Solenoid is activated, hydraulic pressure is applied to the proper shift elements through one of the shift solenoids in the transmission to allow the desired shift. Once the shift is completed the solenoid is turned off.

For complete wiring diagrams, refer to SYSTEM WIRING DIAGRAMS .

The Transmission Control Module (TCM) performs various internal tests to verify proper controller operation. During the power up of the controller, the TCM tests the ability of the TCM to shut down the Solenoid Supply Voltage circuit. The controller monitors the A/D feedback on the Solenoid Supply driver output to ensure that battery voltage is no longer present. Note: A short to voltage on the Solenoid Supply Voltage circuit or any one of the solenoids may set this DTC.

For complete wiring diagrams, refer to SYSTEM WIRING DIAGRAMS .

The Transmission Control Module (TCM) performs various internal tests to verify proper controller operation. This DTC indicates that there is an issue with the TCM's internal clock. If the TCM detects an error with the controllers internal clock, the controller will enter Limp-in mode and illuminate the MIL.

For complete wiring diagrams, refer to SYSTEM WIRING DIAGRAMS .

The Transmission Control Module (TCM) performs various internal tests to verify proper controller operation. This DTC indicates that there is an issue with the TCM's internal watchdog. If the TCM detects an error with the controllers internal watchdog, the controller will enter Limp-in mode and illuminate the MIL.

For complete wiring diagrams, refer to SYSTEM WIRING DIAGRAMS .

The Transmission Control Module (TCM) performs various internal tests to verify proper controller operation. This DTC indicates that there is an issue with the TCM's external watchdog. If the TCM detects an error with the controllers external watchdog, failed the power up test, the controller will enter Limp-in mode and illuminate the MIL.

For complete wiring diagrams, refer to SYSTEM WIRING DIAGRAMS .

The Transmission Control Module (TCM) performs various internal tests to verify proper controller operation. This DTC indicates that the controller's microprocessor internal watchdog has detected an error. If the TCM microprocessor detects an internal watchdog error, the controller will enter Limp-in mode and illuminate the MIL.

For complete wiring diagrams, refer to SYSTEM WIRING DIAGRAMS .

The Transmission Control Module (TCM) performs various internal tests to verify proper controller operation. This DTC indicates that watchdog circuitry external to the microprocessor has detected an error. If the TCM watch dog circuitry external to the microprocessor detects an error, the controller will enter Limp-in mode and illuminate the MIL.

For complete wiring diagrams, refer to SYSTEM WIRING DIAGRAMS .

The Transmission Control Module (TCM) performs various internal tests to verify proper controller operation. This DTC indicates that there is an internal error with the controllers Random Access Memory. If detected, the controller will enter Limp-in mode and illuminate the MIL.

For complete wiring diagrams, refer to SYSTEM WIRING DIAGRAMS .

The Transmission Control Module (TCM) performs various internal tests to verify proper controller operation. This DTC indicates that there is an internal error with the controllers Random Access Memory (RAM) on the CAN controller 1 section of the microprocessor. If detected, the controller will enter Limp-in mode and illuminate the MIL.

For complete wiring diagrams, refer to SYSTEM WIRING DIAGRAMS .

The Transmission Control Module (TCM) performs various internal tests to verify proper controller operation. This DTC indicates that there is an internal error with the controllers Random Access Memory (RAM) on the CAN controller 2 section of the microprocessor. If detected, the controller will enter Limp-in mode and illuminate the MIL.

For complete wiring diagrams, refer to SYSTEM WIRING DIAGRAMS .

The NAG1 transmission has two input speed sensors 1 and 2 (N2 and N3), both speed sensors are located on the valve body. The speed sensors are hall effect speed sensors that are used by the Transmission Control Module (TCM) to calculate the transmissions input speed. Since the input speed could not be measured directly, two of the drive elements are measured. Two input speed sensors were required because both drive elements are not active in all gears.

The input speed sensors 1 and 2 will report the same input speed in gears 2nd, 3rd or 4th. If the 1 and 2 input speed sensor signals are not the same in these gears, the TCM will set the DTC P2784-Input Speed Sensor 1/2 Correlation. The input speed sensor 2 is not reported in 1st and 5th gears. The input speed sensor 1 (N2) is not reported in Reverse. The P1704-Input Speed Sensor 1 Overspeed and P1705-Input Speed Sensor 2 Overspeed DTCs are rationality checks designed to detect a major transmission failure. If either DTC is detected, the TCM will place the transmission in Neutral.

For complete wiring diagrams, refer to SYSTEM WIRING DIAGRAMS .

The Transmission Control Module (TCM) requests torque reductions over the CAN bus during a transmission shift to improve shift quality. The TCM verifies that the PCM / ECM has performed the requested torque reduction by monitoring the response to the request. If the response is not within a specified tolerance, the TCM increments a counter, and if this counter reaches a threshold, the DTC sets.

For complete wiring diagrams, refer to SYSTEM WIRING DIAGRAMS .

The Input Speed Sensor 2 (N3) is one of two hall effect speed sensors that are used by the Transmission Control Module (TCM) to calculate the transmissions turbine speed. Since the turbine speed could not be measured directly, two of the drive elements are measured. Two input speed sensors are required because both elements are not active in all gears.

For complete wiring diagrams, refer to SYSTEM WIRING DIAGRAMS .

The Transmission Control Module (TCM) monitors the friction loss of the torque converter clutch while it is in slipping mode. The TCM calculates friction loss using CAN communication signals such as, engine speed and engine torque, as well as the torque converter turbine speed computed by the TCM. Depending on the friction loss calculated in each program cycle, a corresponding value is added to a factor as long as the torque converter clutch is in slipping mode. The factor is set to 0 when the clutch is opened. If the factor reaches a specified value, a DTC is set.

For complete wiring diagrams, refer to SYSTEM WIRING DIAGRAMS .

The Input Speed Sensors 1 and 2 (N2 - N3) will report the same speed in 2nd, 3rd and 4th gears. If the Input Speed Sensor 1 and 2 signals are not the same in these gears, the DTC will set.

For complete wiring diagrams, refer to SYSTEM WIRING DIAGRAMS .

The Transmission Control Module (TCM) receives information from the Engine, Anti-lock Brake System, and the Electronic Gear Shift control modules over the CAN C bus. The CAN C bus is a high speed communication bus that allows real time control capability between various controllers. Most messages are sent every 20 msec, this means critical information can be shared between controllers. The CAN C bus is a two wire bus with a CAN (+) and a CAN (-) circuit. To reduce the potential of radio and other electrical noise interference, the CAN Bus circuit wiring is manufactured in a twisted pair within the electrical harness.

For complete wiring diagrams, refer to SYSTEM WIRING DIAGRAMS .

The Transmission Control Module (TCM) receives information from the Engine, Anti-lock Brake System, and the Electronic Gear Shift control modules over the CAN C bus. The CAN C bus is a high speed communication bus that allows real time control capability between various controllers. Most messages are sent every 20 mSec, this means critical information can be shared between multiple controllers almost instantaneously. The CAN C bus is a two wire bus with a CAN (+) and a CAN (-) circuit. To reduce the potential of radio and other electrical noise interference, the CAN Bus circuit wiring is manufactured using a twisted pair configuration within the electrical wiring harness.