Seven customer complaints. One disciplined diagnostic process: understand the symptom, collect evidence, isolate the cause, correct it, and verify the result.
This final lighting unit combines position lights, headlamps, stop lamps, turn signals, reverse inputs, electronic LED drivers, and instrument-cluster warning displays. In each case you will identify a failed function and select tests that distinguish it from nearby causes.
Explain power distribution, control requests, output stages, ground returns, and the difference between a symptom and a confirmed cause.
Complete all seven virtual cases with required evidence and repair verification, earn at least 10/12 on the cumulative assessment, and separately document supervised practical tasks.
A complaint such as “the lights don't work” is not a circuit diagnosis. Identify which lamps, which mode, when it fails, and what still operates. Confirm switch selection, ignition state, battery condition, and whether the system is commanded directly or by a module.
If hazard lamps work but one turn mode fails, shared lamp hardware may be functional. Check the unique turn-mode request instead of immediately replacing lamps.
Check brake lamps with pedal released and applied. For reverse-lamp checks, secure the vehicle, chock wheels, and follow OEM procedures; use scan data where appropriate.
SIMPLIFIED LIGHTING SYSTEM: actual vehicles may use separate fuses, modules, network messages, or dedicated wires.
Do not confuse a controller's received request with its output, or its output with actual lamp performance. A cluster may receive a warning request even when a defective display makes the symbol invisible.
Use a loaded voltage-drop test to reveal unwanted resistance. In the dim-headlamp case, a nearly normal feed reading does not rule out a poor return path. Compare voltage across the operating lamp with the voltage lost in its ground path. When a load is not drawing current, a zero ground drop is not proof the ground path is healthy.
With a circuit commanded ON, battery voltage at a fuse input and 0 V at its output can indicate an open fuse. Correct the original fault and restore specified protection; do not bypass it.
Confirm control requests and driver outputs with the approved scan tool and the applicable wiring diagram. Never apply battery power to an unfamiliar electronic module output to “see what happens.”
Recheck the failed condition under its original operating conditions. Compare new measurements to previous evidence; verify every related function still works. For intermittent complaints, repeat the test after warm-up, vibration, or another applicable condition following safe OEM instructions. Document the complaint, test method, reading, diagnosis, correction, and post-repair result.
Select a customer complaint. Every case has its own modeled conditions. Take measurements, select the supported cause, apply an appropriate correction, then retest the relevant point before declaring the case complete.
0 / 7 cases verified
Select a test to add its reading to the job card. Readings reflect the selected case and its modeled conditions; they are not real multimeter outputs.
Choose a test to populate your job card.
Answer all 12 questions. A score of at least 10/12 meets the virtual knowledge target. Review the answer explanations after each submission; retry to improve your understanding.
Use an instructor-approved vehicle or low-voltage trainer, a correct wiring diagram, appropriate PPE, and the manufacturer's procedure. These checklist items are practice records, not verified credentials; an instructor must independently observe the skills.
0 of 8 practice items recorded on this device.