2003 s10 blazer cranks no start . when I was trying to test the crank sensor signal wire I found 10 volts present with ignition on not cranking. the ground wire has 12.5 with the key off and 12.21 volts...
Will a scan tool communicate with it or on the screen does it say NO COMM ! That's how you test a PCM/ECM . If no comm ,check power an ground's ,that's it .
Why were you messing with the crank sensor ? If the fuel pump primes for two seconds there is nothing wrong with it . When cranking the engine the PCM/ECM will only energize the fuel pump if it see's an input from the crank sensor ! You will not see 12 volts on the crank sensor signal return wire ! Crankshaft Position (CKP) Sensor
The CKP sensor is a three wire sensor based on the magneto resistive principle. A magneto resistive sensor uses two magnetic pickups between a permanent magnet. As an element such as a reluctor wheel passes the magnets the resulting change in the magnetic field is used by the sensor electronics to produce a digital output pulse. The PCM supplies a 12-volt, low reference, and signal circuit to the CKP sensor. The sensor returns a digital ON/OFF pulse 3 times per crankshaft revolution for the V6 engine, 4 times for the V8 engine. The CKP sensor reads the crankshaft mounted reluctor wheel to identify pairs of cylinders at top dead center (TDC).
May 20, 2017 |
2003 Chevrolet Blazer