DTC 22

Operation

The crankshaft position sensor functions to detect the crank angle (position) of each cylinder, and to convent those data to pulse signals, which are then input to the engine control module. The engine control module, based upon those signals, calculates the engine rpm, and also regulates the fuel injection timing and the ignition timing.

The power for the crankshaft position sensor is supplied from the ignition switch-IG and is grounded to the vehicle body. The cranksnaft position sensor, by intermitting the flow (to ground) of the 5V voltage applied from the engine control module, produces pulse signals.

Troubleshooting Hints

Hint 1:

If an impact is suddenly felt during driving or the engine suddenly stalls during idling, try shaking the crankshaft position sensor during idling.

If the engine stalls, the cause may be presumed to be improper or incomplete contact of the crankshaft position sensor's connector.

Hint 2:

If the crankshaft position sensor output rpm is 0 rpm during cranking when the engine cannot be started, the cause may be presumed to be a malfunction of the crankshaft position sensor or a broken timing belt.

Hint 3:

If the indicated value of the crankshaft position sensor output rpm is 0 rpm during cranking when the engine cannot be started, the cause may be presumed to be a failure of the ignition coil's primary current to intermittently pulse correctly, so a malfunction of the ignition system circuitry, the ignition coil and/or the ignition power transistor is the probable cause.


Hint4:

If idling is possible even though the cranksnaft position sensor indicated rpm is a deviation from the standard value the cause is usually a malfunction of something other than the crankshaft position sensor.


Examples:

(1) Malfunction of the coolant-temperature sensor
(2) Malfunction of the idling-speed control motor.
(3) Improper adjustment of the standard idling speed.





Inspection








Harness Inspection

Using Oscilloscope





(1) Run the engine at ide speed.
(2) Connect the probe to the oscilloscope pick-up point as shown in the circuit diagram, and check the waveform.