Mar 292017
 

2004 Hyundai SonataNo Spark

Hi I have a 2004 2.4L automatic Hyundai Sonata. I change the timing belt as it has chewed teeth. I also change the head gasket and the 2 exhaust valves on number 4 cylinder. Changed the crank sensor as it had been destroyed by the teeth that were in the timing cover. All back together and I have compression and fuel but no spark. I have checked the crank sensor installation and it is running correctly ie the sensor plate is the right way around and is running correctly through the sensor magnetic field. Ive checked all the timing marks and everything lines up on TDC after numerous revolutions. The crank sensor only has .3 Volts coming from the PCM at the connector to the CKS which I think is the problem as I believe I read it should be around 5 Volts. so it all cranks etc but no spark at the plugs. Any suggestions? My car has 92000 miles. My car has an automatic transmission. Oh I bought the car with the damaged timing belt and stuffed valves so have never heard it start and don’t know its history.


RESPONSE

Crank Sensor Voltage

If the crank sensor is only getting .3 volts and requires 5 volts, I would start there. Check the connections and the wires in the wiring harness. Look for damaged wires or a loss of continuity. Wiggle the wiring with the test leads connected while monitoring the meter.

The crankshaft position (CKP) sensor generates a magnetic pulse signal when the engine is cranking or running. This signal is used by the powertrain control module (PCM) to detect the crankshaft position of each cylinder.

Engine speed is a very important input to the PCM. Crankshaft speed and position are the basis for many calculations made by the computer. Crankshaft position values are transmitted to the computer by pickup coils also known as Permanent Magnet (P/M) generators, Hall Effect sensors or optical sensors. The Crankshaft Position Sensor (CKP) also known as engine speed sensor is typically located in proximity to the crankshaft.

In addition, the PCM uses the CKP sensor in conjunction with the camshaft position sensor to calculate and perform misfire diagnostics.

Related Symptoms

Faulty ignition system components along with loose connections, bad grounds, high resistance or opens in the circuit, may cause the following symptoms:

  • No start condition
  • Stalling after cold start
  • Stalling after hot start
  • Surging off idle
  • Extended crank time when engine is cold
  • Unstable idle
  • Running rough during off idle acceleration
  • Bucking
  • Hesitation
  • Stumble
  • Poor fuel economy
  • Spark knock

 Leave a Reply