Autel AutoLink AL539B [77/92] Start test

8. Start Test

8.1 Starter Test

The function of a vehicle's starting system is to rotate the engine's

crankshaft fast enough so that combustion can take place, and the

engine can begin to run under its own power. This system is

commonly referred to as the "cranking system".

Providing the cranking power needed for reliable engine starts

requires all starting system components to be in good working order.

Testing the starting system can confirm that it is functioning properly,

or provide valuable diagnostic information to isolate a problem in the

system.

The STARTER TEST measures the cranking voltage. If the engine

cranking speed is good, and the cranking voltage reading is within

specifications, you can generally conclude that the starting system is

functioning properly. But, if the starter does not crank, cranks too

slowly, or the volts reading is not within specifications, further

testing will be required. To get more accurate results, this scan tool

incorporates a temperature compensation feature to aid in tests.

Before performing the STARTER TEST, the starting system should

be visually inspected for physical defects, and some preliminary

checks should be performed that will aid you in diagnosing a starting

system problem. These are taken care of during the pretest.

PRETEST

1. To prevent possible personal injury and protest the vehicle from

damage, inspect the starting system for defects. Check for the

following; then repair and/or replace any defective components.

 Battery defects.

 Frayed or broken electrical wiring.

 Corroded or loose connections.

 Loosely mounted starter motor, series-parallel switch,

magnetic switch, solenoid, starter relay, etc.