LS1 · 2002 · COILS / IGNITION
2002 LS1 Individual Ignition / Coil Diagnosis
Each cylinder has an individual coil, but the system still contains shared bank feeds and grounds. The pattern tells you what to test first.
APPLICATION: 2002 Firebird / Formula / Trans Am 5.7L LS1. Exact 2002 electronic-ignition architecture controls.
What the system is doing
- The PCM controls eight individual ignition-control circuits using crank and cam information.
- Each bank of four coils also depends on ignition voltage, low-reference and ground paths.
One cylinder
- Confirm the misfire follows that cylinder.
- Inspect plug, wire, coil connection and control path.
- A controlled component swap can be useful evidence when done one variable at a time and verified afterward.
Several cylinders on one bank
- Check the shared ignition feed/ground and related fuse/circuit before replacing multiple coils.
- The factory diagnostic specifically uses multiple same-bank misfire counters as a clue to a shared problem.
Intermittent / hot failure
- Reproduce RPM, load, vehicle speed and temperature from failure records when possible.
- Inspect connector fit and harness movement under the same condition; do not test only after the car cools and then call it fixed.
DO NOT REPLACE YET
A P0300 or dead cylinder does not automatically prove the coil. Prove coil command, power/ground, secondary path and cylinder fuel/mechanical health.
FPV DIAGNOSTIC RULE
OBSERVE → MEASURE → ISOLATE → PROVE → REPAIR → VERIFY. A code or symptom identifies the next test, not the part to buy.
AFTER THE FAILURE IS PROVEN
Use the proven failed branch—not the original symptom—to choose the replacement. Go from diagnosis to the Parts Verdict →