Transmission Data Definitions
TRANSMISSION TECH 1 DATA DEFINITIONSA list of "Transmission" data messages displayed on the Tech 1 scan tool will be explained. This information will assist in emission or driveability problems. The displays can be viewed while the vehicle is being driven.
With the Tech 1 connected, the Traction Control System (TCS) may be disabled and the "Service TCS" lamp may turn "ON."
ENGINE SPEED - Range 0-9999 RPM - Engine speed is computed by the Powertrain Control Module (PCM) from the distributor reference input (low resolution circuit). It should remain close to desired idle under various engine loads with engine idling.
TRANS OUTPUT SPEED - Scan tool displays 0 RPM to 8191 RPM - This parameter indicates the rotational speed of the transmission output shaft expressed as revolutions per minute.
ENG COOL TEMP - Range -40°C to 151°C, -40°F to 304°F - The Engine Coolant Temperature (ECT) sensor is mounted in the coolant pump and sends engine temperature information to the PCM. The PCM supplies 5 volts to the ECT sensor circuit. The sensor is a thermistor which changes internal resistance as temperature changes. When the sensor is cold (internal resistance high), the PCM monitors a high signal voltage and interprets it as a cold engine. As the sensor warms (internal resistance decreases), the voltage signal will decrease and the PCM will interpret the lower voltage as a warm engine.
TRANS FLUID TEMP - Scan tool displays a range of -40°C to 151°C, 40°F to 304°F - This parameter is the input signal of the transmission fluid temperature sensor. Transmission fluid temperature is high (151°C) when signal voltage is low (0 volt), and transmission fluid temperature is low (-40°C) when signal voltage is high (5 volts).
THROT POSITION - Range 0-5.00 Volts - Used by the PCM to determine the amount of throttle demanded by the driver. The display should read 0.36-0.96 volt at idle to greater than 4 volts at wide open throttle.
THROTTLE ANGLE - Range 0 - 100% - Computed by the PCM from Throttle Position (TP) sensor voltage (throttle position) and should display 0% at idle and 100% at wide open throttle. Refer to DTC 21 if TP sensor angle is not 0% at idle.
A/B/C RANGE (RNG) - Scan tool displays ON/OFF, ON/OFF, ON/OFF - These parameters are the three inputs from the transmission range pressure switch assembly. "ON" represents a B+ voltage signal, "OFF" represents a 0 voltage signal.
TRANS RANGE SWITCH (SW) - Scan tool displays a range of Invalid, Park/Neutral. Reverse, Drive 4, Drive 3, Drive 2, and Low - This parameter is the decoded status of the three A/B/C range inputs from the transmission range pressure switch assembly and represents the position of the transmission manual valve.
COMMANDED GEAR - Scan tool displays a range of 1, 2, 3, or 4 - This parameter is the decoded commanded state of the 1-2 and 2-3 shift solenoids. Gear 1 = ON, ON. Gear 2 = OFF, ON. Gear 3 = OFF, OFF. Gear 4 = ON, OFF.
ADAPTABLE SHIFT - This value indicates if the current shift will update the 1-2 adapt tables. The adapt tables are used to modify line pressure. The following items cause a shift not to be adaptable:
^ Braking pressure (manual gear ranges).
^ Long shift delay (shift delay is the time the solenoid changes state until the shift starts).
^ Long shift time.
^ Throttle range.
^ Significant throttle angle change.
^ Hot mode.
^ Transmission fluid temperature range.
^ Manual gear ranges (D1, D2).
^ If shift starts too soon after the solenoid state change.
^ Diagnostic failures - 21, 22, 24, 28, 53, 58, 59, 72,73, 75, 79, 81, or 82.
^ Time since last shift.
^ Time since the last range change.
^ Significant vehicle speed change.
1 - 2 SOLENOID (SOL)/2-3 SOLENOID (SOL) - Scan tool displays ON/OFF - These parameters are the commanded status of the 1-2 and 2-3 shift solenoids. "ON" represents a commanded energized state (current flowing through solenoid). "OFF" represents a commanded non-energized state (current not flowing through solenoid).
CONTROL (CTR) FEEDBACK (FDBK) 1/2 2/3 - Scan tool displays "OK" or "FAULT." - These parameters are the actual states of the 1-2 and 2-3 shift solenoid driver control circuits.
TCC PWM SOLENOID Displays ON/OFF - This parameter is the commanded state of the TCC PWM solenoid. "ON" indicates a commanded energized state (current flowing through the solenoid). "OFF" indicates a commanded non-energized state (current not flowing through the solenoid).
3 - 2 CONTROL SOLENOID (SOL) - Scan tool displays a range of 0% to 100% - This parameter is the commanded percentage of "ON" time of the 3-2 Control Solenoid. "0%" represents a completely "OFF" (non- energized) commanded state. "100%" represents an "ON" (energized) commanded state.
3 - 2 CONTROL (CTR) FEEDBACK (FDBK) - Scan tool displays "OK" or "FAULT." - This parameter is the actual state of the 3-2 control solenoid driver control circuit.
HOT MODE - The scan tool will display this value either "NO" or "YES." When displayed "YES," the transmission fluid temperature has become greater than 135°C and the following actions will occur:
1. The TCC will engage in fourth gear, except when the brakes are applied, low TP signal, or a DTC is stored.
2. When the fluid temperature obtains 150°C but, less than 154°C for 15 minutes, DTC 79 will set. When DTC 79 is set, TCC application will still occur in the same criteria as when hot mode started.
3. When fluid temperature increases from 150°C for 1 second, in a time period less than 15 minutes, DTC 79 will not set. DTC 58 will set when transmission fluid temperature is greater than 154°C for 1 second.
4. When DTC 58 is set and in hot mode, the vehicle will retain hot mode criteria until the next ignition cycle.
5. If fluid temperature cools from 135°C down to less than 125°C, hot mode criteria will discontinue.
TCC SLIP SPEED - Scan tool displays a range of -4096 RPM to +4095 RPM. - This parameter is the difference between transmission input speed (derived from the distributor reference pulses, or crankshaft/camshaft position sensors) and transmission output speed (derived from the vehicle speed sensor). A negative value indicates input speed is less than output speed (deceleration). A positive value indicates input speed is greater than output speed (acceleration). A value of zero indicates input speed is equal to output speed (TCC applied).
TCC SOLENOID - Scan tool displays ON/OFF - This parameter is the commanded state of the TCC solenoid. "ON" indicates a commanded energized state (current flowing through the solenoid). "OFF" indicates a commended non-energized state (current not flowing through the solenoid).
CONTROL (CTR) FEEDBACK (FDBK) TCC SOL - Scan tool displays "OK"/" FAULT. " - This parameter is the actual state of the TCC solenoid driver control circuit.
DESIRED PRESSURE CONTROL SOLENOID (PCS) - Scan tool displays a range of 0.00 amp to 1.10 amps - This parameter is the commanded current of the pressure control solenoid circuit. 0.00 amps (no current flow) indicates commended higher line pressure. 1.10 amps (high current flow) indicates commanded lower line pressure.
ACTUAL PRESSURE CONTROL SOLENOID (PCS) - Scan tool displays a range of 0.00 amp to 1.10 amps This parameter is the actual current of the pressure Control solenoid circuit at the control module. 0.00 amps (no current flow) indicates actual higher line pressure. 1.10 amps (high current flow) indicates actual lower line pressure.
PRESSURE CONTROL SOLENOID (PCS) DUTY CYCLE - Scan tool displays a range of 0% to 100%. - This parameter is the commanded state of the pressure control solenoid expressed as a percent of energized on- time. 0% indicates zero on-time (non-energized) or no current flow. 100% indicates maximum on-time (energized) or high current flow. Normal operations range is 0%-60%.
MPH Km/h - Scan tool displays a range of 0 mph to 255 mph. - This parameter is input signal from the vehicle speed sensor.
VEHICLE SPEED - Range 0-255 km/h, mph - The vehicle speed sensor signal is converted into km/h and mph for display.
TCS/ASR ACTIVE - Tech 1 displays YES/NO - When the TCS/ASR system is active, the Tech 1 will display "YES."
TCC FLUID TEMP SWITCH - Tech 1 Displays Open/Closed - This parameter indicates the state of the TCC fluid temp switch circuit input. At 164°C (327°F), the switch will close and the input to the PCM drops to 0 volts. When the switch is open the input voltage will be B +.
TCC BRAKE SWITCH - Scan tool displays OPEN/CLOSED. - This parameter indicates the state of the TCC brake switch circuit input. Open indicates a 0 voltage input (brake switch open, brake pedal applied). Closed indicates a B+ voltage input (brake switch closed, brake pedal released).
KICKDOWN ENABLED - Scan tool displays NO/YES - This parameter indicates whether enabling conditions exists for an acceleration mode downshift. "NO" indicates enabling conditions (throttle position, vehicle speed, input speed, etc.) do not exists for an acceleration mode downshift. "YES" indicates enabling conditions exists for an acceleration mode downshift.
1-2 SHIFT TIME - Scan tool displays a range of 0.00 seconds to 6.38 seconds. - This parameter is the actual time of the last 1-2 shift. These are accurate unless adaptable indicates YES.
2-3 SHIFT TIME - Scan tool displays a range of 0.00 seconds to 6.38 seconds. - This parameter is the actual time of the last 2-3 shift. Please refer to road test procedure in section 7A14A to achieve accurate 2-3 shift time. 2-3 shift time is normally between 0.3 sec and 1.35 sec.
1 - 2 SHIFT ERROR - Scan tool displays a range of 0.00 seconds to 6.38 seconds - This parameter is the difference between the desired 1-2 shift time and the actual 1-2 shift time.
CURRENT (CURR) ADAPT CELL - Scan tool displays a range of NOT USED, 25% TP CELL, 40% TP CELL and 70% TP CELL. - This parameter indicates the current throttle position cell used for fluid line pressure modification (adaptation). N/A represents 0% to 25% throttle angle. 25% TP CELL represents 25% to 39% throttle cell. 40% TP CELL represents 40% to 70% throttle angle. 70% TP CELL represents 70% to 100% throttle angle.
ENG/TRANS DTC DETECTED - Tech 1 Displays YES/NO - This will display "YES" if the PCM detects a fault in an engine or transmission circuit that caused a DTC.
PARK/NEUTRAL POS - Tech 1 displays - P-N-- or -R-DL - P-N-- displayed indicates that the gear select lever is in park or neutral.
SYSTEM VOLTAGE - Range 0.0-25.5 Volts - This represents the system voltage measured by the PCM.