Heres how to test the crankshaft position sensor thodle position sensor and map sensor
See Figure 1
Fig. 1: Attach suitable jumper wires between the CKP sensor and CKP sensor harness. A DC volt meter can then be attached to the necessary terminals to test the sensor as the engine is being cranked
Typically, when a crankshaft position sensor DTC is set, checking the integrity of the wiring connecting the sensor (using a digital volt meter) to the PCM harness connector is the best way to determine if the sensor is faulty. If the wires all have continuity, and a DTC is set, it is probable that the sensor is faulty.
Although a procedure is given here for testing of the crankshaft sensor itself, it is generic, and may not apply to every vehicle. Typically, the crankshaft position sensor harness connector wire leads are labeled. However, it is advisable to use this procedure in conjunction with the wiring diagrams in to identify the terminals on the crankshaft sensor before connecting test leads.
Turn the ignition key OFF.
Unplug the sensor electrical harness and check the terminals for corrosion and damage.
Check the sensor wiring harness wires for continuity and repair as necessary.
Attach the sensor harness making sure it is firmly engaged.
Using a Digital Volt Ohm Meter (DVOM) set on the DC scale, backprobe the sensor signal terminal (terminal A) with the positive lead of the meter and backprobe the sensor ground terminal (terminal B) with the negative lead of the meter.
Have an assistant crank the engine and observe the meter.
You should have approximately a 5 volt reference signal pulse. If not the sensor may be defective.
Fig. 2: The TPS is located on the side of the throttle body
Fig. 3: Inspect the voltage of the TPS when the linkage is closed, then ....
Fig. 4: ... check for change when the TPS linkage is at WOT
Disconnect the TPS harness from the TPS.
Using suitable jumper wires, connect a digital voltmeter to terminals A and B on the TPS.
With the ignition ON and the engine running, the TPS voltage should be 0.450-1.25 volts at base idle to approximately 4.5 volts at wide open throttle.
If the reading on the TPS is out of specification, replace it.
Turn ignition OFF, remove jumper wires, then reconnect harness to throttle position switch.
See Figures 2 and 3
Backprobe with a high impedance voltmeter at MAP sensor terminals A and C.
With the key ON and engine off, the voltmeter reading should be approximately 5.0 volts.
If the voltage is not as specified, either the wiring to the MAP sensor or the PCM may be faulty. Correct any wiring or PCM faults before continuing test.
Backprobe with the high impedance voltmeter at MAP sensor terminals B and A.
Verify that the sensor voltage is approximately 0.5 volts with the engine not running (at sea level).
Record MAP sensor voltage with the key ON and engine off.
Start the vehicle.
Verify that the sensor voltage is greater than 1.5 volts (above the recorded reading) at idle.
Verify that the sensor voltage increases to approximately 4.5. volts (above the recorded reading) at Wide Open Throttle (WOT).
If the sensor voltage is as specified, the sensor is functioning properly.
If the sensor voltage is not as specified, check the sensor and the sensor vacuum source for a leak or a restriction. If no leaks or restrictions are found, the sensor may be defective and should be replaced.
Fig. 2: Using jumper wires and a high impedance voltmeter test between MAP sensor terminals A and C with the key ON and engine off. The voltage should be approximately 5 volts
Fig. 3: Next test between MAP sensor terminals A and B with the key ON and engine off. The voltage should be approximately 0.5 volts
Saturday, November 22nd, 2008 AT 5:42 PM