ASE4 Engine Electrical Systems 3

Question 1

A vehicle with a smart charging system shows 12.6V on the scan tool but 14.4V on a voltmeter at the battery. The discrepancy is because:

Accepted Answer

The BCM is reporting battery voltage, not alternator output voltage

Answer

The scan tool is inaccurate and should be calibrated

Answer

The alternator is overcharging

Answer

The battery has a bad cell causing a false reading

Question 2

A no-start complaint: the engine cranks normally but will not start. Battery and charging tests are normal. The technician should next check:

Accepted Answer

Spark, fuel pressure, and injector pulse with a noid light

Answer

The battery ground cable

Answer

Starter current draw

Answer

Charging voltage under load

Question 3

Excessive AC ripple on the charging circuit (above 0.5 volts AC) can cause:

Accepted Answer

ECM and module faults, erratic sensor readings, and communication errors

Answer

Battery overcharging and boiling

Answer

Low charging voltage at idle

Answer

Hard starting due to low current output

Question 4

The purpose of the battery's CCA (Cold Cranking Amps) rating is to indicate:

Accepted Answer

The current a battery can deliver at 0°F for 30 seconds while maintaining 7.2 volts

Answer

The total energy storage capacity of the battery in watt-hours

Answer

The maximum charging current the battery can accept

Answer

The normal operating temperature range of the battery

Question 5

A voltage drop test on the ground side of the starting circuit shows 0.6 volts. This indicates:

Accepted Answer

Excessive resistance in the ground circuit reducing starter power

Answer

Normal ground circuit resistance

Answer

The starter is drawing too much current

Answer

The battery ground cable needs replacement at the battery end only

Question 6

A technician measures 14.1 volts at the battery with the engine running and all accessories on. This reading indicates:

Accepted Answer

Normal charging system output

Answer

The alternator is undercharging the battery

Answer

The battery has a bad cell causing a false high reading

Answer

The voltage regulator is failing high