My 2002 alero has 65,000 miles and ran great until I was in an accident a few days ago. I tried to start it and it wouldn't start. The check engine light came on and the low track light too. After a few attempts it kicked over, however it was shaking, making loud noises, and when I was depressing the accelerator to the floor of my car, the car would not accelerate. When stopped a light it would try to shut off. The car then began smoking and was undrivable. Any ideas?

Sounds like the Crankshaft sensor is damaged and needs to be replaced.
The Camshaft position sensor works along with the Crankshaft position sensor.
Determining the timing and injectors’ pulse, to deliver fuel to the cylinders.
The Camshaft position sensor is a hall sensor, which it triggered by a magnet in the Camshaft.

On 4 cyl(2.4) models the Camshaft position sensor is located to the left side of the timing cover.
On the V6(3.1 & 3.4) it’s located at the front of the engine block (passenger side), below the power steering pump.
Check the terminals for breaks and looseness, repair if needed.
Here is the plug indentification picture.
The wires are different for the 4cyl and V6, Please note below.
Though the plugs are the same three wire connectors.
Plug is as listed : 1 - Camshaft position sensor signal on 4 cyl,
12 volt supply on the V6
2 – Sensor ground 4 cylinder,
Camshaft position sensor signal on the V6
3 – 12 volt supply on the 4 cylinder,
sensor ground on the V6

First check for voltage and ground circuits from the PCM.
Disconnect the electrical connector from the Camshaft sensor and connect the positive lead (on the wiring harness) of the voltmeter to the red wire(#3) on the 4 cyl and the red/white wire on the V6(#1).

Connect the negative to the pink/black wire on the 4 cyl(#2), or black on the V6(#3).
Turn the key on, the voltmeter should read 12 volts, if not check the wiring to the PCM.
If the circuits are good, have the PCM checked out by a Dealer or other properly trained shop.
To check the operations;
Reconnect the Camshaft position sensor, using a probe to back probe the brown/white wire terminal of the camshaft PS. Plug locations on4 cyl (#1) and theV6(#2)
Connect the positive lead of the voltmeter to the probe and the negative to a good engine ground.
Turn the key on, the voltmeter should read approx 10 volts.

*Rotating the engine by hand with a breaker bar attached to the crank pulley. Watching the voltmeter, the voltage should remain a steady 10volts then quickly drop to zero and back to 10vlts as the magnet passes the sensor.
If the tests results are incorrect then replace the camshaft position sensor.

* Rotating the engine slowly, and at least two full revolutions of the engine for accurate results.


Camshaft sensor Replacement

On the 4 cylinder
- Disconnect the electrical connector
- Remove the camshaft position sensor-mounting bolt and pull the sensor out of the camshaft cover.
- Replace the “O” ring and lightly lubricate it with clean engine oil.
- Install in the reverse of those procedures.

On V6
- Remover the drive belt.
- Remove the power steering unit but don’t disconnect the hoses, just lay it aside.
- Disconnect the electrical connector from the harness; paying attention to the route the wires are in.
- Remove the camshaft ps mounting bolt and pull the sensor out of the block.
- Install in reverse procedure.

If the sensor flange breaks off and you cant remove the CPS, try screwing a heavy screw into the top of the sensor and pulling it out with plyers/vise-grips.
Good luck and thank you for using Fixya

Sounds like the fuel mix could be off. Ordinarily I'd suspect the oxygen sensor. However since you've had an accident, is there any chance that the engine wiring harness could have been damaged during the accident? It's possible that the accident could have damaged the computer also. Sorry, it's hard to be more definitive. Sounds like it needs to be hooked up to a computer diagnostic machine. Good luck!