QuestionQUESTION: My 98 Sebring 2.5 coupe won't start unless I jump out the ASD relay. I've checked the OBD and no codes are produced. I've replaced the crank sensor. Still only runs when jumped out. If it will run when the ASD is jumped out, does that mean the PCM is receiving sensor inputs? Or could the cam sensor be the culprit? I'm at a loss without any codes being thrown. Any help will be appreciated.
ANSWER: Hi Jami,
How about the ASD relay itself being faulty? Have you tried substituting another relay with the same part number for it (being sure that the relay you "borrow" isn't also necessary to running the engine, of course). My understanding is that if the pcm doesn't get signals necessary to operate the ignition system that it will open the ASD relay. But because the engine is running I would believe that it is satisfied with the signals from the sensors.
How are you trying to get the codes? You can't get them by means of the ignition switch, I believe, but rather only with a code reader. If the engine runs fine with the ASD jumped out, then I would have to believe that there is no reason to replace the distributor/cam sensor (a very expensive part). You also could test the ASD for function (click) and for continuity when it has closed the points. It could click but have internal contacts that are corroded or burned or fouled. Just you the battery across 4- and 6+ to get the click, and read continuity between 2 and 8.
Let me know what you learn as this is a new one on me.
Roland
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QUESTION: Thanks for the fast response, Roland. I used an OBD2 borrowed from Autozone that produced no codes. I did check the ASD for function and it checked out ok. So I jumped 87 to 30 respectivily on the plug and 86 and 30 were hot so I just made 30 to 87 and the car started immediately and after running it for a minute, it still produced no codes.
ANSWER: The ASD relay coil will close the contacts if it has 12v on pin 6 and the powertrain controller grounds pin 4 (side to side location on the socket). That closure connects pin 8 to pin 2 (bottom to top of socket) that then powers the spark and injector circuits. So about the only thing to check would be the connection between the ASD coil grounding lead (pin 4) and pin 67 at the powertrain controller, and check to see what happens at pin 4 when you crank the engine (it should be grounded at that moment). That is the basic control of the ASD and you have verified that the 12V is coming on two of the four pins, which leaves the issue to whether pin 4 is or isn't being grounded. Again this assumes the relay is working as it should (just in case try substitution of a like relay). I have not heard of any reason why the PCM would not ground the relay, yet still be satisfied enough with the signals from the sensors that it will produce pulese for the spark and injectors. It may be, but I just have not heard of that experience. You could measure the pulse voltage on both the cam and the crank sensors which should oscillate between 5 and 0.3V as you turn the engine over by hand with a ratchet on the crank pulley bolt (with ignition on, of course). Measure between the brown and black/green, and the blue/white and black/green, respectively for those sensors.
If the voltage is off value in either direction, then that might be a basis for sensor replacement.
Please let me know what you learn.
Roland
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QUESTION: No relay to changeout. Checked it again still good. Checked pulse voltage both cam & crank sensors-good. Not sure how to verify grounding from 67 at PCM to 4 at ASD plug. While cranking, checked voltage from 6 to 4 at ASD plug, had 10.2 volts??
AnswerHi Jami,
If the battery voltage on 6 measures 12.4 or so compared to ground while you are cranking, then that might suggest there is something wrong in the pcm which should be near 0 I would guess (just see what for reads compared to ground). So see what it measures compared to ground while cranking. I don't know what the mininmum voltage across the relay coil is to get it to close so that is the bottom line: whether the difference between 6 and 4 will or won't close the ASD relay while you are cranking. It may be the ASD will close with full battery voltage, but not with 10.2 volts, in which case the question is should the voltage be higher than 10.2 or is the relay just weak and needs replacement. Maybe 10.2 is just the voltage the battery will put out while it is cranking and you may need a new battery? I can't give you any specs on that, but you a handle on it now. Maybe buying a new relay is the most economical use of your funds, otherwise the choice is a new battery or worse a PCM (or an identically numbered one from a wreck, with perhaps needing to be reprogammed at a dealer for an additional cost). The circuit seems to be working, but just not enough voltage to close the ASD.
Thanks for the update; I'll be interested in the result.
Roland
