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Home >> GMC >> 1997 >> Yukon 4WD V8-6.5L DSL Turbo VIN S >> Repair and Diagnosis >> Powertrain Management >> Computers and Control Systems >> Testing and Inspection >> Symptom Related Diagnostic Procedures >> No Scan Tool Data
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No Scan Tool Data

Diagnostic Chart:




Diagnostic Chart:




Diagnostic Chart:









Circuit Description

There should always be a steady Malfunction Indicator Lamp (MIL) when the ignition is ON and engine OFF. Battery ignition voltage is supplied to the lamp. The PCM will turn the lamp ON by grounding the ignition feed circuit.

Test Description

Number(s) below refer to the step number(s) on the Diagnostic Table.

3. Check that the Scan Tool is functioning properly on another vehicle. If the scan is functioning properly, and CKT the serial data circuit is OK, the PCM may be at fault for the NO DLC symptom.

5. If the light goes OFF when the PCM connector is disconnected, then the control circuit is not shorted to ground.

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