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

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

by in Torrington, WY on March 02, 2013
1 answer 4 comments
ANSWER by on March 02, 2013
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.
COMMENT by on March 02, 2013
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!
COMMENT by on March 02, 2013
how do i test asd,camshaft sensor,crank sensor?
COMMENT by on March 02, 2013
You stated already tested relays! Look at the reply to the first answer on how to check asd. No bus light on in dash??
COMMENT by on March 02, 2013
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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fuel pump wont turn on,checked all relays and fuses, no spark,it cranks but wont start