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See Figures 1 and 2
The Crankshaft Position Sensor, or CKP sensor provides the PCM with information about engine speed and crankshaft position. It is located near the bellhousing.
The CKP sensor contains a Hall effect device which sends either a 0.0 volt or a 5.0 volt signal to the PCM depending on the position of the distributor shaft.
The PCM uses the CKP sensor signal to determine fuel injection event time among other things. The engine will not run without the CKP sensor signal.
Fig. 1: View of the crankshaft position sensor and its location-1996 5.2L engine shown
Fig. 2: View of the crankshaft position sensor and its location-1996 4.0L engine shown
See Figures 3 and 4
Fig. 3: Connector terminals for the Crankshaft Position (CKP) sensor
Fig. 4: Checking the CKP sensor voltage between the wiring harness side and battery ground
Backprobe with a high impedance ohmmeter between the CKP sensor connector middle terminal and battery ground.
Verify that the resistance is less than 5 ohms. If the resistance is not as specified, repair or replace the wiring as necessary and continue the test.
With the ignition ON and the engine OFF, backprobe with a high impedance voltmeter between the sensor connector middle terminal and either of the end terminals.
Verify that a 5 volt or greater signal is present at one of the two terminals. If not as specified, repair or replace the wiring as necessary and continue the test.
With the ignition ON and the engine OFF, backprobe with a high impedance voltmeter between the sensor connector middle terminal and the end terminal that did not have the 5 volt or greater signal.
Crank the engine and verify that the voltage reading alternates between 0.0 and 5.0 volts or verify that the voltage reading is 2.5 volts (averaging voltmeters only).
If the voltage readings are not as specified, the sensor may be faulty.
It is not firing because you have no spark the automatic shut down relay enables spark, fuel pump, and injector pulse.
It is energized by the ECM when it receives a signal from the crank shaft position sensor.
The info is from a 4.0 engine because the info on the 2.5 doesn't include a crank sensor test proceedure
All 1993-95 2.5L and 4.0L Engines are equipped with multi-port fuel injection. The ignition system on these engines is operated by the Powertrain Control Module (PCM) and consists of:
Secondary ignition cables
Distributor (contains rotor and camshaft position sensor)
Powertrain Control Module
Crankshaft position sensor
Failure To Start Test
See Figures 1, 2, 3 and 4
Fig. 1: Special jumper wire construction for grounding the coil
Fig. 2: Common coil harness connector
Fig. 3: Coil terminals
Fig. 4: PCM 60-way electrical connector
Apply parking brake and block wheels before performing any engine running tests, including idle or timing checks and adjustments.
Check battery voltage and determine that a minimum of 12.4 volts is available for operation of cranking and ignition systems.
Crank engine for 5 seconds while monitoring voltage at coil positive terminal. If voltage remains near 0 during entire period of cranking, please refer to Fuel System in this guide for on-board diagnostic checks of PCM and auto shutdown relay.
If measured voltage is near battery voltage but drops to 0 after 1-2 seconds of cranking, please refer to Fuel System in this guide for on-board diagnostic checks of distributor reference pick-up circuit to PCM.
If measured voltage remains near battery voltage for entire 5 second cranking period, turn key OFF and remove SBEC 60-way connector. Check 60-way connector for any spread terminals.
Remove the wire-to-coil positive terminal and connect regular jumper wire between coil positive terminal and battery positive terminal.
Using a special jumper cable, momentarily ground terminal No. 19 of the PCM 60-way connector. A spark should be generated when ground is removed:
If spark is generated, replace the PCM.
If no spark is seen, use a special jumper to ground the coil negative terminal directly. If spark is produced by directly grounding the negative coil terminal, but was not produced with pin No. 19, trace and repair open condition within wiring harness. If no spark is produced when directly grounding the coil, the faulty ignition coil should be replaced.
Secondary Circuit Testing
Remove the center wire from the distributor cap.
Using insulated pliers, hold the terminal end about 1/2 in. (13mm) from a good engine ground and crank the engine.
Check for steady arcing. If steady arcing does not occur, inspect the secondary coil cable. Also, inspect the distributor cap and rotor for cracks or burn marks, then repair as necessary.
Remove the cable from one spark plug.
Using insulated pliers, hold the terminal end about 1/2 in. (13mm) from the block or head and crank the engine.
If a spark occurs, check ECU sensors using tester DRB II, or equivalent. If the sensors check out okay, the problem is probably in the fuel system.
If no spark occurs, The rotor, distributor cap or spark plug wires are defective.
Are you getting a 5 volt pulse at the crank sensor? if so Did you check the circuit back to the ECM?
Also are you sure you change the auto shut down relay ? Compare the relay wiring to the one in the schematic.(colors the same)