Transmission Control Module Scan Tool Information (MVA)

The Transmission Control Module Scan Tool Data List contains all transmission related parameters that are available on the scan tool. The list is arranged in alphabetical order. A given parameter may appear in any one of the data lists, and in some cases may appear more than once, or in more than one data list in order to group certain related parameters together.

The values below represent a typical display recorded from a properly functioning system.

IMPORTANT: Do not use a scan tool that displays faulty data. Report the condition to the scan tool manufacturer. The use of a faulty scan tool can result in misdiagnosis and the unnecessary replacement of parts.

Only the parameters listed below are used/referenced in this manual for diagnosis. If a scan tool displays other parameters, those values are not recommended by General Motors for use in diagnosis.

The scan tool values from a properly functioning transmission may be used for comparison with the transmission you are diagnosing. The values below represent a typical display recorded from a properly functioning system.

Transmission Control Module Scan Tool Data Parameters

Parameter	System State	Expected Value	Definition
A/T Oil Temperature 1	-	Varies	The scan tool displays temperature (°C or °F). This is the current A/T oil temperature.
Lock Up	-	OFF	The scan tool displays ON or OFF. ON if lock up. Off if except lock up.
Lock Up Solenoid Status	-	OFF	The scan tool displays ON or OFF. This is the current status of the lock up solenoid.
Neutral Position SW Signal	-	OFF	The scan tool displays ON or OFF. ON if shift lever position is P and N. Off if shift lever position is not P or N.
Shift Status	-	1st	The scan tool displays 1st, 2nd, 3rd or 4th (O/D). This is the actual shift lever position.
Shift SW Status (2 Range)	-	ON	The scan tool displays ON or OFF. On if shift lever position is 2. Off if shift lever position not 2.
Shift SW Status (3 Range)	-	OFF	The scan tool displays ON or OFF. ON if shift lever position is 3. Off if shift lever position is not 3.
Shift SW Status (D Range)	-	ON	The scan tool displays ON or OFF. ON if shift lever position is D and 3. Off if shift lever position is not D and 3.
Shift SW Status (L Range)	-	OFF	The scan tool displays ON or OFF. ON if shift lever position is L. Off if shift lever position is not L.
Shift SW Status (N Range)	-	OFF	The scan tool displays ON or OFF. ON if shift lever position is N. Off if shift lever position is not N.
Shift SW Status (P Range)	-	OFF	The scan tool displays ON or OFF. ON if shift lever position is P. Off if shift lever position is not P.
Shift SW Status (R Range	-	Varies	The scan tool displays ON or OFF. ON if shift lever position is R. Off if shift lever position is not R.
SPD (NC)	-	Varies	The scan tool displays RPM. This is the counter gear speed.
SPD (NT)	-	Varies	The scan tool displays RPM. This is the input turbine speed.

Transmission Control Module Scan Tool Output Controls

Scan Tool Output Control	Description
Activate the Lock Up	This output control is used to control the shift solenoid DSL to set the automatic transaxle to the lock-up condition.
Activate the Solenoid (DSL)	This output control is used to control the operation of the shift solenoid DSL.
Activate the Solenoid (SL1)	This output control is used to control the operation of the shift solenoid SL1.
Activate the Solenoid (SL2)	This output control is used to control the operation of the shift solenoid SL2.
Activate the Solenoid (SL4)	This output control is used to control the operation of the shift solenoid SL4.
Activate the Solenoid (SLT)	This output control is used to control the operation of the shift solenoid SLT and raise the line pressure.
Control the Shift Position	This output control is used to control the operation of the shift solenoid valves.