Acura 37500-P72-A01 Crank-Tdc Sensor Assembly

These are three sensors connected to the distributor that measure when the crankshaft hits its highest position, to help determine when each cylinder completes its cycle. The PCM uses the CKP signal to control when the engine gets fuel and air, change the ignition spark timing, and measure how fast the engine turns. The TDC sensor helps set the right timing for the spark plug during engine starts. The CYP sensor tells the PCM when to deliver fuel to each cylinder in order. First, technicians search for error messages and then measure the right resistance for each sensor by unplugging the electrical wire. To check the sensors, disconnect the electrical connector at the distributor and measure the resistance across the terminals: Testing CKP at terminals 2 and 6, TDC at terminals 3 and 7, and CYP at terminals 4 and 8, we check electrical resistance and compare against rated values. As you test, make sure each lead gets no electrical connection to an engine ground for both terminals at once. You have to change the distributor when any of the sensors shows values beyond the accepted range or when any terminal connects directly with ground.

The crankshaft fluctuation sensor features a pulse rotor on the front end of the crankshaft and a pickup sensor mounted on the engine adjacent to the rotor, with the PCM utilizing the signal to monitor changes in the crankshaft's rotational speed; if these changes surpass a predetermined limit, a misfire is indicated. To check the sensor, locate the electrical connector at the timing belt end of the engine, ensuring the key is in the OFF position before disconnecting it. An ohmmeter should be connected between the two outer terminals of the connector, with a reading of 1.6 to 3.2 k-ohms indicating proper function; if the reading is outside this range, the sensor needs replacement. Additionally, connecting the ohmmeter between body ground and each of the sensor's outer terminals should show no continuity; if it does, the sensor must be replaced. For replacement, remove the valve cover, crankshaft pulley, and timing belt cover, then disconnect the sensor's electrical connector and remove its mounting bolt, with installation following the reverse order of removal.