Symptom Router
You should not need to know the failed part before you can use FPV. Describe the symptom, choose a system, then follow the diagnostic path that matches the actual year and configuration.
Cranks but will not start
No spark, no injector operation, fuel or distributor-reference branch.
LT1 · 1994Cranks but will not start
Exact-year preliminary checks and symptom split.
LT1 · 1995Cranks but will not start
Factory-backed crank/no-start workflow.
LT1 · 1993Stalls intermittently
Capture spark, injector and reference behavior while the failure is present.
LT1 · 1996Misfire / P0300
Separate ignition, fuel, mechanical and modification-related causes.
LT1 · 1996No crank / slow crank
Battery, cable, control and starter path before parts.
LT1 · 1996Security / VATS fuel enable
Separate theft-deterrent authorization from fuel and ignition faults.
LT1 · 1994Cooling fans not working
Identify command, relay, feed and motor branches.
LS1 · 2002Cranks but will not start
Starting condition, fuel, spark, injector and security branches.
LS1 · 2002Misfire / P0300
Prove cylinder, ignition, injector, fuel or mechanical cause.
LS1 · 2002Rough / lean / fuel-trim problem
Use scan data and operating condition before blaming an O2 sensor.
LS1 · ModifiedBoth banks lean
Modified-car checkpoints for intake, exhaust, calibration and fuel delivery.
LS1 · 2002Overheating / coolant loss
Separate true overheating, fan control, circulation and leakage.
LS1 · 2002Low / no fuel pressure
Test pressure and electrical delivery under load before a pump.
4L60EP1870 / TCC slip
Separate converter-clutch apply problems from internal transmission slip.
4L60EHot TCC dropout
Reproduce the hot failure and isolate command, input and hydraulic causes.
T56 · 2002Will not go into gear
Separate clutch-release trouble from shifter/internal transmission trouble.
T56 · 2002Clutch pedal / release complaint
Pedal feel, hydraulics, release travel and mechanical branches.
Chassis · 2002Wheel bearing / hub noise
Road-test and isolate hub noise before replacement.
Chassis · 2002Pulls / wanders
Tires, alignment, steering, suspension and brake-drag branches.
Brakes · 2002Brake pulsation
Separate rotor-related pulsation from hub/runout and other causes.
ABS · 2002ABS / wheel-speed fault
Prove sensor, wiring, tone/sensing architecture and module inputs.
FirebirdHeadlight door grinds / clicks
Mechanical gear and motor diagnosis before replacing the whole assembly.
Body · 2002Headlamp doors do not operate
Separate command/module, feed, motor and mechanical faults.
ElectricalBattery dies while parked
Battery and charging first, then a controlled parasitic-draw test.
Body · 2002Power windows do not work
Shared power/RAP, switch, wiring, motor and binding branches.
Body · 2002Wipers / washers do not work
Choose the exact failed mode before testing the circuit.
Body · 2002Fuel gauge wrong / dead
Separate sender, circuit, cluster and input problems.
HVAC · 2002Blower does not work
Power, control, resistor/module and blower-motor branches.
A/C · 2002Compressor clutch will not engage
Do not jump refrigerant or compressor conclusions; verify enable conditions.
Modified carProblem started after modifications
Start with what changed and prove compatibility before blaming unrelated stock parts.
Modified carWheel / tire rub
Locate the contact point and separate static fitment from dynamic clearance.
Modified carDriveline vibration after mods
Check working angles, mounts, torque arm and driveline configuration.
Modified carRear suspension complaint
Diagnose the installed rear suspension and axle combination, not the VIN alone.
No direct symptom route matched. Search the full FPV database →
Exact-year starting, cooling, fuel & drivability paths
Choose the exact model year before using a hard specification or control path.
Modified-car symptoms
If the complaint started after a modification—or the car is no longer stock—start with the installed combination, not the VIN assumptions.
CLUTCH / SHIFT HYDRAULIC DIAGNOSTICS
4L60E MODIFIED-CAR DIAGNOSTICS
Converter and tune complaints now split command, calibration, hydraulic apply and internal capacity before parts are condemned.
Modified LS1 Fueling / Airflow Diagnostics
Proof-first journeys for injector, fuel-system, MAF/intake and long-tube/O₂ changes.
Modified Ignition / Cooling / Electrical Diagnostics
Post-modification faults now split power, ground, command, calibration and component failure before replacement.
Browse all diagnostic journeys
If symptom-first routing is not enough, use the complete diagnostic index.
Open all diagnostic journeys →Dynamic Brake / T56 Electronics / Vehicle Identity
New proof-first paths cover dynamic wheel/caliper and brake-hose fitment, uneven pad wear, Magnum reverse lockout/VSS/reverse lights, and VIN-versus-installed-configuration checks.