Preliminary Checks

WITH 4L60-E AUTOMATIC TRANSMISSION

PRELIMINARY CHECKS - BEFORE USING THIS SECTION
Before using this section you should have performed the Diagnostic System Check and determined that:

1. The control module and Malfunction Indicator Lamp (MIL) (Service Engine Soon) are operating correctly.
2. There are no diagnostic trouble codes stored or there is a diagnostic code but no MIL (Service Engine Soon). Refer to Computers and Control Systems / System Diagnosis / Flow of Diagnosis.
Testing and Inspection

Several of the following symptom procedures call for a careful visual/physical check. The importance of visual/physical checks cannot be over stressed, because they can lead to correcting a problem without further checks and can save valuable time.

VISUAL/PHYSICAL CHECK
This check should include:
- Control module grounds for being clean, tight and in their proper location.
- Vacuum hoses for splits, kinks and proper connections, as shown on the "Vehicle Emission Control Information" label. Check thoroughly for any type of leak or restriction.
- Air leaks at all mounting areas of the intake manifold sealing surfaces.
- Ignition wires for cracking, hardness, proper routing, or carbon tracking.
- Wiring for proper connections, pinches, and cuts.
- The following symptom charts contain groups of possible causes for each symptom and cover several engines.

These procedures are not necessarily meant to be done in consecutive order. If TECH 1 scan tool readings do not indicate the problems, then proceed in a logical order, easiest to check or most likely cause first. To determine if a particular system or component is used on a specific vehicle, refer to the system diagrams at Diagrams / Electrical. Electrical Diagrams

SYMPTOM
Verify the customer complaint, and locate the correct symptom in the table.