Here is a very simple guide i stole from another place. For the less mechanically saavy, it can help for sure.
Won't turn over, won't click, won't anything:
Is there power to the accessories?
NO - power distribution problem. Verify battery is good and power is making it to the central junction box and fuse box.
YES – continue
Is the PATS light flashing rapidly?
NO – continue
YES – PATS problem. Key is corrupt or not programmed, reciever is damaged or disconnected. ECU is damaged.
Is the Clutch in? (if equipped)
NO – depress clutch pedal all the way
YES – verify that the clutch switch is working properly by measuring resistance across the 2 wires when the clutch is depressed, should be 0 ohms, then continue.
Is the transmission in Park or Neutral? (if equipped)
NO – Move selector switch to Park or neutral.
YES – verify that the lever is actually moving the selector switch on the transmission to park or neutral, measure the resistance of the safety switch when in park or neutral, should be 0 ohms. then continue.
Do you have an alarm or lockout?
NO - continue
YES – verify that the alarm is disabled and the lockout is working properly.
Is the grey wire near the coil pack connected?
NO - connect
YES – continue
Is your engine ground less than 100 ohms?
NO – add a ground wire from a lift point to the chasis or batt-.
YES – continue
Is there power to the starter?
NO – repair broken wire or terminal.
YES – continue.
Is the starter grounded?
NO - repair engine to chasis ground wire.
YES - continue.
Is there 12v on the key terminal when the key is in the "start" position?
NO - check operation of the ignition switch, ignition relay, and fuse.
YES - bad starter.
Clicks, won't turn over or start:
Are the battery terminals connected securely and corrosion free?
NO – clean and secure the terminals
YES – continue
Will the car jump start?
NO - continue
YES – bad battery or charging circuit.
Is your engine ground less than 100 ohms?
NO – add a ground wire from a lift point to the chasis or batt-.
YES – continue
Will the rotating assembly turn freely?
NO – engine is jammed or seized
YES – continue
Is the starter seated correctly?
NO – seat properly and tighten bolts.
YES – continue
Does the starter motor turn when power is applied and load removed?
NO – bad starter
YES – have starter bench tested.
Cranks, turns over, but won't start or run:
Is there gas in the car?
NO – buy gas
YES – continue
Are the spark plugs firing?
NO – no signal from crank angle sensor or faulty coil pack/coil harness.
YES – continue
Can you hear the fuel pump whir for 2 seconds when the key is set to “on”?
NO – look under the passenger side kick panel and verify that inertia switch is not tripped and is working correctly. Fuel pump problem if switch is ok.
YES – use a fuel pressure gauge to verify that you are receiving adequate fuel pressure during cranking. Continue if ok
With the oil cap off and a friend trying to start the car, can you see the cams spinning while the engine cranks?
NO - Possibly a bad timing belt. Pull the timing gear cover off to check the belt and watch the cam gears. Replace belt if bad.
YES - continue
Are the injectors firing?
NO – damaged ECU or no signal from camshaft position sensor. (could be a broken timing belt)
YES – continue
Is there adequate compression in all cylinders?
NO – broken timing belt, head gasket leak, or damaged valvetrain componant.
YES – continue
Is there a blockage in the air intake?
NO – verify engine timing, have ECU tested.
YES – remove blockage
Won't turn over, won't click, won't anything:
Is there power to the accessories?
NO - power distribution problem. Verify battery is good and power is making it to the central junction box and fuse box.
YES – continue
Is the PATS light flashing rapidly?
NO – continue
YES – PATS problem. Key is corrupt or not programmed, reciever is damaged or disconnected. ECU is damaged.
Is the Clutch in? (if equipped)
NO – depress clutch pedal all the way
YES – verify that the clutch switch is working properly by measuring resistance across the 2 wires when the clutch is depressed, should be 0 ohms, then continue.
Is the transmission in Park or Neutral? (if equipped)
NO – Move selector switch to Park or neutral.
YES – verify that the lever is actually moving the selector switch on the transmission to park or neutral, measure the resistance of the safety switch when in park or neutral, should be 0 ohms. then continue.
Do you have an alarm or lockout?
NO - continue
YES – verify that the alarm is disabled and the lockout is working properly.
Is the grey wire near the coil pack connected?
NO - connect
YES – continue
Is your engine ground less than 100 ohms?
NO – add a ground wire from a lift point to the chasis or batt-.
YES – continue
Is there power to the starter?
NO – repair broken wire or terminal.
YES – continue.
Is the starter grounded?
NO - repair engine to chasis ground wire.
YES - continue.
Is there 12v on the key terminal when the key is in the "start" position?
NO - check operation of the ignition switch, ignition relay, and fuse.
YES - bad starter.
Clicks, won't turn over or start:
Are the battery terminals connected securely and corrosion free?
NO – clean and secure the terminals
YES – continue
Will the car jump start?
NO - continue
YES – bad battery or charging circuit.
Is your engine ground less than 100 ohms?
NO – add a ground wire from a lift point to the chasis or batt-.
YES – continue
Will the rotating assembly turn freely?
NO – engine is jammed or seized
YES – continue
Is the starter seated correctly?
NO – seat properly and tighten bolts.
YES – continue
Does the starter motor turn when power is applied and load removed?
NO – bad starter
YES – have starter bench tested.
Cranks, turns over, but won't start or run:
Is there gas in the car?
NO – buy gas
YES – continue
Are the spark plugs firing?
NO – no signal from crank angle sensor or faulty coil pack/coil harness.
YES – continue
Can you hear the fuel pump whir for 2 seconds when the key is set to “on”?
NO – look under the passenger side kick panel and verify that inertia switch is not tripped and is working correctly. Fuel pump problem if switch is ok.
YES – use a fuel pressure gauge to verify that you are receiving adequate fuel pressure during cranking. Continue if ok
With the oil cap off and a friend trying to start the car, can you see the cams spinning while the engine cranks?
NO - Possibly a bad timing belt. Pull the timing gear cover off to check the belt and watch the cam gears. Replace belt if bad.
YES - continue
Are the injectors firing?
NO – damaged ECU or no signal from camshaft position sensor. (could be a broken timing belt)
YES – continue
Is there adequate compression in all cylinders?
NO – broken timing belt, head gasket leak, or damaged valvetrain componant.
YES – continue
Is there a blockage in the air intake?
NO – verify engine timing, have ECU tested.
YES – remove blockage
