With 4L60-E Transmission

Data Link Connector(DLC):

DATA LINK CONNECTOR
The Powertrain Control Module (PCM) can communicate a variety of information through Data Link Connector (DLC) terminal "M." This data is transmitted at high frequency which requires a scan tool for interpretation.

With an understanding of the data which the scan tool displays, and knowledge of the circuits involved, the scan tool can be very useful in obtaining information which would be more difficult or impossible to obtain with other equipment.

Scan tools do not make the use of diagnostic charts unnecessary, nor can they indicate exactly where a problem is in a particular circuit. Diagnostic tree charts incorporate diagnosis procedures using a scan tool where possible and most charts require the use of a scan tool when it is applicable.

NOTICE: Tech 1 tool that displays faulty data should not be used and the problem should be reported to the manufacturer. The use of a faulty scan tool can result in misdiagnosis and unnecessary parts replacement.

The tech 1 scan tool has the ability to save time in diagnosis and prevent the replacement of good parts. The key to using the scan tool successfully for diagnosis lies in the technician's ability to understand the system being diagnosed as well as an understanding of the scan tool's limitations.

SCAN TOOL USE WITH INTERMITTENTS
In some scan tool applications, the data update rate makes the tool less effective than a voltmeter, such as when trying to detect an intermittent problem which lasts for a very short time. However, the Tech 1 allows manipulation of wiring harnesses or components under the hood with the engine not running, while observing the Tech 1 readout.

The Tech 1 tool can be plugged in and observed while driving the vehicle under the condition when the Malfunction Indicator Lamp (MIL) (Service Engine Soon/Check Engine) turns "ON" momentarily or when the engine driveability is momentarily poor. if the problem seems to be related to certain parameters that can be checked on the Tech 1, they should be checked while driving the vehicle. If there does NOT seem to be any correlation between the problem and any specific circuit, the Tech 1 can be checked on each position, watching for a period of time to see if there is any change in the readings that indicates intermittent operation.
The Tech 1 is also an easy way to compare the operating parameters of a poorly operating engine with those of a known good one. For example, a sensor may shift in value but not set a diagnostic trouble code. Comparing the sensor's readings with those of a known good vehicle may uncover the problem.

The scan tool has the ability to save time in diagnosis and prevent the replacement of good parts. The key to using the scan tool successfully for diagnosis lies in the technician's ability to understand the system he is trying to diagnose as well as an understanding of the scan tool operation and limitations. The technician should read the tool manufacturer's operating manual to become familiar with the tool's operation.

T1OO - GM CAMS
The T1OO-GM CAMS (Computerized Automotive Maintenance System) is a computerized technician's terminal unit. When connected to a vehicle, performs engine, electronic circuits and systems test to find possible vehicle problems in the engine system or the PCM.

The terminal diagnoses as follows:

^ Circuit diagnostic procedures provide information on how to isolate a problem and repair requirements.
^ If no problem exists, engine performance problems are diagnosed.
^ DTCs stored in the PCM are read and diagnosed by the system.

Also needed are a test light, ohmmeter, digital voltmeter with 10 megohms impedance (J 39200), vacuum gage and jumper wires for diagnosis. Special tools which are required for system service. Refer to Tools and Equipment. Tools and Equipment