ASE Electrical and Electronic Systems 3

Question 1

A fully rested battery shows an open-circuit voltage of 12.4 volts. Its approximate state of charge is:

Accepted Answer

75%

Answer

About 12.6 V is full charge and 12.4 V corresponds to roughly 75% state of charge.

Question 2

During a battery load test at 70°F (21°C) using half the CCA rating for 15 seconds, voltage should not fall below:

Accepted Answer

9.6 volts

Answer

A good battery maintains at least 9.6 V at 70°F during a 15-second half-CCA load test.

Question 3

With the battery disconnected, resistance measured between CAN High and CAN Low at DLC pins 6 and 14 on a healthy high-speed CAN bus should be about:

Accepted Answer

60 ohms

Answer

Two 120-ohm terminating resistors in parallel produce about 60 ohms total.

Question 4

A fuse blows instantly every time a circuit is switched on. The most likely cause is:

Accepted Answer

A short to ground before the load

Answer

A short to ground ahead of the load bypasses its resistance, causing excessive current that blows the fuse.

Question 5

A starter cranks slowly while drawing much higher than specified current. Which is the most likely cause?

Accepted Answer

Shorted starter armature or engine mechanical binding

Answer

High current with slow cranking points to excessive load such as a shorted armature or a tight engine.

ASE - Automotive Service Excellence Certified Tech Practice Test