Battery and starting is one area on A6, 9 of the 50 scored questions. It asks you to test a battery properly, measure what the starter draws and what its cables lose, and tell an electrical slow crank from a mechanical one.
9questions on the test
18%of the scored questions
15practice questions here
What the area covers
What the 2026 task list asks for in battery and starting:
Battery type and layout: the guide says low-voltage energy storage system, which takes in non-traditional chemistry, multi-battery setups and boost capacitors, not just one lead-acid battery.
State of charge, load and capacitance tests, and charging to the maker's procedure.
Electronic memory: keeping or restoring it when the battery is disconnected.
Jump-starting with cables, a booster battery or an auxiliary power supply.
Cables, clamps, hold-downs, trays and vent tubes.
Starter current draw and starter circuit voltage drop.
Starter circuit parts: starter, relays, solenoids, modules, switches and wiring.
Slow crank, no crank, extended crank or a cranking noise: electrical or engine mechanical?
Reading a starter problem
Start with the battery: a starter test on a weak battery tells you nothing. Then sort by what the starter draws while cranking:
High draw, slow crank. The starter or the engine is working too hard. Worn bushings, a dragging armature, grounded field coils, or an engine that is hard to turn, such as a seized accessory. The EXCEPT sample in the 2026 guide lists causes like these against one that cannot raise draw.
Low draw, slow crank. Resistance is limiting current: corroded cable ends, a loose engine ground, burned solenoid contacts. A voltage drop test on each cable while cranking finds which.
Click, no crank. The solenoid gets its signal but the motor doesn't get its current. Burned contacts and a poor cable connection both fit.
No click. Look at the control side: ignition switch, park/neutral or clutch switch, starter relay, and the immobilizer or module that enables cranking.
Trap: a battery that reads full
Open-circuit voltage shows state of charge, not capacity. A battery can read full and still collapse under load, so a voltmeter alone never clears it: follow up with a load or capacitance test, and use the test the maker specifies for AGM or lithium batteries.
15 battery and starting questions
0 of 15 answered · 0 correct
Question 1 of 15 · Battery and Starting System Diagnosis and Repair · 18%Not answered
A vehicle has just been driven and is shut off. A technician measures battery voltage and finds 13.2 V. Technician A says the battery is overcharged. Technician B says the technician should wait several hours or apply a load to remove the surface charge before checking open-circuit voltage. Who is correct?
Explanation
Incorrect: Technician A mistakes surface charge for overcharging; 13.2 V right after driving is normal.
Correct: Technician B is right: surface charge must be removed, by resting or a brief load, before a true open-circuit reading.
Incorrect: Technician A is wrong, because a fresh 13.2 V reading is surface charge, not overcharge.
Incorrect: Technician B correctly calls for removing surface charge before reading open-circuit voltage.
Question 2 of 15 · Battery and Starting System Diagnosis and Repair · 18%Not answered
A vehicle has a sluggish cranking condition. A technician measures 12.6 V across the battery posts with the key off and concludes the battery is perfectly healthy. Which essential diagnostic step was omitted?
Explanation
Incorrect: Another open-circuit reading, even on a scope, still shows only state of charge.
Incorrect: Ripple testing checks alternator diodes and says nothing about battery capacity.
Correct: Open-circuit voltage shows state of charge only; a load or conductance test shows whether the battery can deliver cranking current.
Incorrect: Starter draw is measured while cranking, not with the engine idling.
Incorrect: A draw test explains a battery that drains while parked; it does not measure cranking capacity.
Question 3 of 15 · Battery and Starting System Diagnosis and Repair · 18%Not answered
A technician performs a cranking voltage test on a standard 12-volt system at 70°F (21°C). The ignition is disabled, and the engine cranks for 15 seconds. What is the minimum acceptable voltage reading during this test?
Explanation
Correct: At 70°F a good battery should hold at least 9.6 V through a 15-second load or cranking test.
Incorrect: 12.0 V is close to a resting voltage, and no battery holds that while cranking.
Incorrect: 12.6 V is a fully charged battery at rest, not a cranking value.
Incorrect: 10.5 V is the end point used for reserve capacity ratings, not the cranking minimum.
Incorrect: 13.5 V is a charging voltage with the engine running and cannot occur while cranking.
Question 4 of 15 · Battery and Starting System Diagnosis and Repair · 18%Not answered
A vehicle exhibits a slow, labored engine crank accompanied by the interior lights dimming significantly. When the technician turns the key again, only a rapid clicking sound is heard from the starter relay. Swapping the starter motor did not resolve the issue. What should the technician have checked first?
Explanation
Incorrect: The swapped starter replaced the solenoid too, and the battery still had to be verified first.
Incorrect: Alternator output matters once the engine runs; it does not explain a collapse while cranking.
Incorrect: The relay clicks, so the start signal reaches it; the shortfall is power to the starter.
Incorrect: A mechanical drag check comes after the battery and cables are proven good.
Correct: Dimming lights and rapid clicking mean voltage collapses under load, so the battery and its terminals come first.
Question 5 of 15 · Battery and Starting System Diagnosis and Repair · 18%Not answered
During an engine cranking test, a technician measures a 1.2-volt drop across the negative battery cable. The starter motor current draw during this exact measurement was 150 amps. Based on Ohm's law, what is the calculated electrical resistance of the negative battery cable?
Explanation
Incorrect: 0.1200 Ω divides 1.2 V by 10 instead of by 150 A.
Incorrect: 0.8000 Ω at 150 A would drop 120 V, impossible on a 12 V system.
Incorrect: 0.0125 Ω would need a 1.875 V drop at 150 A.
Correct: R = V ÷ I = 1.2 V ÷ 150 A = 0.008 Ω.
Incorrect: 0.0008 Ω slips the decimal point one place.
Question 6 of 15 · Battery and Starting System Diagnosis and Repair · 18%Not answered
An engine cranks slowly. The battery and all cable connections pass load tests, and the engine rotates freely when turned by hand. Starter current draw measures 250 A; specification is 150 to 180 A. What is the most likely starter fault and the necessary action?
Explanation
Incorrect: The engine turns freely by hand, which rules out a mechanical bind.
Incorrect: The battery passed its load test, and a weak battery lowers draw rather than raising it.
Incorrect: An open field winding reduces or stops current, so it cannot cause 250 A.
Incorrect: Burned contacts add resistance and cut starter current, the opposite of 250 A.
Correct: Battery, cables and engine all check out and draw is far over spec, so a shorted armature or field inside the starter is left.
Question 7 of 15 · Battery and Starting System Diagnosis and Repair · 18%Not answered
A vehicle cranks slowly, and a scan tool reports no communication with multiple modules. Battery voltage at rest is 10.5 V. Technician A says to charge and test the battery first. Technician B says to diagnose the CAN bus for a short. Who is correct?
Explanation
Correct: Technician A is right: a battery resting at 10.5 V can cause both the slow crank and the lost communication, so it is charged and tested first.
Incorrect: Technician B jumps to the network while the battery is low enough to cause the no-communication codes by itself.
Incorrect: Diagnosing the CAN bus first is premature with a 10.5 V battery, so only Technician A is right.
Incorrect: Technician A's charge-and-test step is the correct place to start.
Question 8 of 15 · Battery and Starting System Diagnosis and Repair · 18%Not answered
A battery is rated at 650 CCA. A conductance tester measures 520 CCA at 32 deg F (0 deg C). According to the manufacturer's specification, the battery must be replaced if the measured CCA is below 70% of the rated CCA at this temperature. What is the correct assessment?
Explanation
Incorrect: Replacing a battery that meets the manufacturer's criterion is unnecessary.
Incorrect: The battery already met the criterion as tested, so no retest is called for.
Correct: 70 % of 650 is 455 CCA, and 520 CCA is above it, so the battery passes.
Incorrect: Failure starts below 455 CCA, and this battery measured 520 CCA.
Incorrect: 520 CCA clears the 455 CCA cutoff, so it does not fail.
Question 9 of 15 · Battery and Starting System Diagnosis and Repair · 18%Not answered
After replacing a failed battery, a technician verifies that the engine cranks and starts, then returns the vehicle to the customer. Which of the following best evaluates this practice?
Explanation
Incorrect: A load test proves the new battery, not the charging system or key-off draw.
Incorrect: A new battery can still be drained by a parasitic load or left flat by a weak alternator.
Incorrect: Nothing requires an alternator with a battery; it is replaced only if testing shows a fault.
Incorrect: A start check shows the new battery has charge, not why the old one failed.
Correct: Batteries usually fail for a reason, so charging output and key-off draw are verified before release.
Question 10 of 15 · Battery and Starting System Diagnosis and Repair · 18%Not answered
Time (sec)
Voltage at Starter
Current Draw (A)
1.0
9.2 V
155 A
3.0
9.0 V
150 A
5.0
9.1 V
148 A
A technician is evaluating an automotive starting system. Using the provided measurements recorded during a 5-second engine crank, calculate the total electrical power being consumed by the starter motor under steady cranking conditions exactly at the 3.0-second mark.
Explanation
Incorrect: 1.890 kW would require 12.6 V at 150 A, the resting voltage rather than the cranking voltage.
Incorrect: 1.575 kW would require 10.5 V at 150 A, not the 9.0 V recorded.
Incorrect: 1.426 kW uses the 1.0-second row (9.2 V × 155 A) instead of the 3.0-second mark.
Correct: P = V × I = 9.0 V × 150 A = 1,350 W, or 1.350 kW.
Incorrect: 1.347 kW does not match 9.0 V × 150 A at the 3.0-second mark.
Question 11 of 15 · Battery and Starting System Diagnosis and Repair · 18%Not answered
When replacing a battery in a late-model vehicle, which procedure is MOST important to prevent system memory loss?
Explanation
Incorrect: The negative cable comes off first for safety, and the order does not save memory either way.
Incorrect: Engine temperature has nothing to do with whether modules lose memory.
Incorrect: Key-on during a disconnect risks voltage spikes and does not keep memory.
Correct: A memory saver keeps modules powered through the swap, so presets, learned values and settings survive.
Question 12 of 15 · Battery and Starting System Diagnosis and Repair · 18%Not answered
A vehicle intermittently will not crank. Bypassing the starter relay with a jumper starts the engine. During the no-crank condition, there is no voltage at the relay control terminal from the PCM, the ignition switch START signal at the PCM input is 12 V, and the scan tool shows the park/neutral input as 'in gear' with the shifter in Park. What is the most likely cause?
Explanation
Correct: The PCM gets the start request but reads 'in gear' with the shifter in Park, so it withholds the relay command because of a bad park/neutral input.
Incorrect: The relay never receives a command from the PCM, so the relay is not the fault.
Incorrect: Jumping the relay cranks the engine, which proves the starter ground.
Incorrect: The engine starts when the relay is jumped, so the starter works.
Incorrect: The PCM is doing what it should when its park/neutral input says the transmission is in gear.
Question 13 of 15 · Battery and Starting System Diagnosis and Repair · 18%Not answered
What is the minimum battery state of charge for accurate load testing?
Explanation
Incorrect: A full charge is ideal but not required; 75 % is the accepted minimum.
Incorrect: At 50 % a good battery can still fail the load test from low charge alone.
Correct: Load test results mean something only at about 75 % charge or more, so a lower battery is charged first.
Incorrect: At 25 % even a good battery fails a load test simply because it is discharged.
Question 14 of 15 · Battery and Starting System Diagnosis and Repair · 18%Not answered
What is the proper battery electrolyte specific gravity reading for a fully charged battery?
Explanation
Incorrect: 1.100 is close to a fully discharged cell.
Incorrect: 1.000 is plain water, which means a completely dead cell.
Correct: About 1.265 is the specific gravity of a fully charged lead-acid cell at 80°F.
Incorrect: 1.400 is above any normal electrolyte reading.
Question 15 of 15 · Battery and Starting System Diagnosis and Repair · 18%Not answered
During a crank attempt, the starter motor spins at full speed and the drive pinion moves out, but the engine does not turn. What should be checked?
Explanation
Incorrect: The starter spins at full speed, so it is getting enough voltage.
Incorrect: A poor ground would slow the starter, and it spins at full speed.
Incorrect: The pinion moves out, so the solenoid is shifting it.
Correct: Full-speed spin with the pinion out but no engine rotation means the overrunning clutch is slipping or the pinion teeth are stripped.
Whether the starter pulls more or less current than spec while cranking. Read it with an inductive clamp on the battery cable. High draw points to a dragging starter or a hard-to-turn engine; low draw to resistance in the cables, connections or solenoid.
How many battery and starting questions are on A6?
9 of the 50 scored questions, 18%. Battery and starting are one area in the 2026 guide, not two.
Is a slow crank always electrical?
No. The task list asks you to separate electrical causes from engine mechanical ones. Normal draw with good cable voltage drops points away from the starter circuit and toward the engine.