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1998 Dodge Ram Van 1500 Question: how do i test camshaft sensor with multimeter

 

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cobracop29, Torrington, WY, March 02, 2013, 11:08
 Rookie

fuel pump wont turn on,checked all relays and fuses, no spark,it cranks but wont start

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  • Answer #1

    lightsaber March 02, 2013, 11:55
     Journeyman

    The ASD relay controls both the fuel injectors, and ignition system, and operates when the PCM gets the correct signal from the crankshaft position sensor. Start your testing with the ASD relay, and then the crankshaft position sensor. The CPS tends to fail frequently and cause intermittent rough running.

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    pushrod, March 02, 2013, 12:47
    Profile_thumbnail
     Master

    I agree, except asd should close/click with key on. They give a lot of trouble, also ecm provides the ground circuit to make it work. Have seen this circuit fail but that is just one scenario. Others possible! Can remove asd relay, turn key on, put relay back, does it click? Try it as many times as needed. Better way is a GOOD scanner to check this out!

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    cobracop29, March 02, 2013, 13:17
     Rookie

    how do i test asd,camshaft sensor,crank sensor?

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    pushrod, March 02, 2013, 15:23
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     Master

    You stated already tested relays! Look at the reply to the first answer on how to check asd. No bus light on in dash??

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    lightsaber, March 02, 2013, 15:32
     Journeyman

    ASD relay testing methods:
    If you swap the ASD relay for another relay of the same type from an inconsequential circuit in your power distribution box you can basically confirm if the relay is good or not. By the book method follows:
    Holding relay with terminals facing you (three across the top & two down) numbered from left to right then down: 86, 87A, 85, 87, 30
    Terminal number 30 is connected to battery voltage.
    For both the ASD and fuel pump relays, terminal
    30 is connected to battery voltage at all times.
    The PCM grounds the coil side of the relay
    through terminal number 85.
    Terminal number 86 supplies voltage to the coil
    side of the relay.
    When the PCM de-energizes the ASD and fuel
    pump relays, terminal number 87A connects to terminal
    30. This is the Off position. In the off position,
    voltage is not supplied to the rest of the circuit. Terminal
    87A is the center terminal on the relay.
    When the PCM energizes the ASD and fuel
    pump relays, terminal 87 connects to terminal 30.
    This is the On position. Terminal 87 supplies voltage
    to the rest of the circuit.
    The following procedure applies to the ASD and
    fuel pump relays.
    (1) Remove relay from connector before testing.
    (2) With the relay removed from the vehicle, use
    an ohmmeter to check the resistance between terminals
    85 and 86. The resistance should be 75 ohms +/-
    5 ohms.
    (3) Connect the ohmmeter between terminals 30
    and 87A. The ohmmeter should show continuity
    between terminals 30 and 87A.
    (4) Connect the ohmmeter between terminals 87
    and 30. The ohmmeter should not show continuity at
    this time.
    (5) Connect one end of a jumper wire (16 gauge or
    smaller) to relay terminal 85. Connect the other end
    of the jumper wire to the ground side of a 12 volt
    power source.
    (6) Connect one end of another jumper wire (16
    gauge or smaller) to the power side of the 12 volt
    power source. Do not attach the other end of the
    jumper wire to the relay at this time.
    WARNING: DO NOT ALLOW OHMMETER TO CONTACT
    TERMINALS 85 OR 86 DURING THIS TEST.
    DAMAGE TO OHMMETER MAY RESULT.
    (7) Attach the other end of the jumper wire to
    relay terminal 86. This activates the relay. The ohmmeter
    should now show continuity between relay terminals
    87 and 30. The ohmmeter should not show
    continuity between relay terminals 87A and 30.
    (8) Disconnect jumper wires.
    (9) Replace the relay if it did not pass the continuity
    and resistance tests. If the relay passed the tests,
    it operates properly. Check the remainder of the ASD
    and fuel pump relay circuits. Refer to 8, Wiring Diagrams.

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