Mechanics

DODGE STRATUS TERMINAL PROBLEM

1998 Dodge Stratus

1998 Dodge Stratus V6 cranks over but will not start. I tested the automatic shutdown relay to insure proper PDC operation according to instructions in Haynes Manual, I verified terminal 30 of the relay has voltage present all the time, next step is to check terminal 86, where according to the manual I should only have voltage when the ignition is in the ON position, but I have voltage when the ignition is in the OFF position. Could this be the source of my problem?
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Jbleck
February 3, 2013.



Lets skip all that for now. Measure the voltage on the dark green / orange wire at the ignition coil or any injector. You should see 12 volts for one second after turning on the ignition switch. If you do, the ASD relay circuit is working and the Engine Computer has control of it. Next, that voltage must come back during cranking.


Caradiodoc
Feb 3, 2013.
I measured the voltage on the dark green/orange wire and a injector and I do not have 12 volt (I get at 1 or 2). I want to check the crankshaft position sensor, how do I do that?


Tiny
Jbleck
Feb 3, 2013.
The crank and cam sensor only come into play during cranking. Was that lack of voltage during cranking or for one second when you turned the ignition switch on? If there was no voltage for that first one second, the sensors aren't even in the picture yet.

The easiest way to test the crank sensor is to view it on a scanner that displays live data. Both of them will be listed as "no" or "present" during cranking. You can try testing them with a digital voltmeter but the results will not be conclusive. The supply wire will have 5.0 volts whenever the ignition switch is on. The ground wire, commonly black with a blue tracer, will have 0.2 volts. Use the AC volts scale on the signal wire. All I can suggest is you might see something. Your meter is designed to measure a sine wave at 60 cycles per second. The sensor puts out three or four square wave pulses which the meter will have a hard time responding to, and that series of pulses only occurs three times per engine revolution. Digital meters take a reading, analyze it, then display it while taking the next reading. Those pulses turn on and off repeatedly which will likely make the meter reading bounce all over. I use an oscilloscope for tv repair. That would do a better job of displaying the signal coming from the sensor.

To add confusion to the story, your ASD relay is wired differently than in previous models so your service manual might be wrong. Below is my sad drawing of the typical relay layout and common terminal numbering with the numbers you're using. The next one shows the Stratus relay. Two terminals must have 12 volts all the time. The ignition switch is no longer involved in the relay's coil circuit. This would agree with what you found already.

To measure terminal 93 you must have the relay installed. Raise it up enough to fit the meter probe onto the terminal, or wrap a piece of wire around the relay's terminal to use as a test point. I don't like to stuff a wire in beside the terminal because it could stretch the terminal in the socket and cause an intermittent connection. You should see 12 volts there when the relay is turned off. The relay is turned on when terminal 93 gets grounded and the voltage goes close to 0 volts.

You can ground terminal 93 too, then test for 12 volts at the coil or injectors. If you have that, all that leaves is the Engine Computer is not grounding that terminal.


Caradiodoc
Feb 3, 2013.