Questionhello again now this is whats happening all of the relays have stopped chattering and ive got 12 volts to the coil. i left a spark plug out to chech for sparks and when i try to start it all i get is 1 spark and then nothing else. i can turn the key off and try again and all i get is 1 spark again. i have replaced all the following components,cam sensor, crank sensor, coil, and the pcm as well as the relays. the van almost starts now and then dies because the spark stops.
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It is the starter fuse #10 in the junction block and its only getting 7 v while the key is in the on position and goes to 12v when you attempt to start the van. The fuel pump relay was only clicking when the ASD relay was jumped and after I turned the key off, it clicked for only about 30 seconds then quit. Breaker 1 I got 85 to ground 0v, 30 to ground .04 v, 86 to ground 10.85v, 87a to ground I got .04v, and 87 to ground 10.86 v. I have a 99 Chrysler t&c with a 3.8 liter v-6 automatic. I couldnt get any resistance from pin #87 to ground with both o2 sensors unplugged and when I jumped the ASD relay I got no spark at the plug.
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Jumped pin #30 to #87 and it produced 12v at the coil but it still wouldnt start. Tested #30 to ground and got 11.56v. Tested #86 to ground and also got 11.56v. Tested all the fuses in the panel under the dash and under the hood and found one fuse that didnt have 12 v and it was the starter fuse it only had 7.06 v. Still not starting. Left the fuse out and started pulling relays and voltage never went up or down. Also once I jumped pin #30 to #87 and tried to start it, when I stopped cranking the fuel pump relay started clicking again until I pulled the jumper. I cant figure this out please help.
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Pulled out the ASD relay and I am not getting any voltage across the #30 and #86. The 317 fuse is good. Checked the wire at the coil again and still getting 3-4.5 volts. The check engine light was on but when i replaced the computer then i guess it lost the codes but it had one before that that said we had an oxygen sensor bad,and I think it was the rear. I unhooked the rear o2 sensor and looped it and the voltage went up to 7.5 volts at the coil. I unhooked all the components cam and crank sensors, coil, o2 sensors, and still no voltage across pin #30 and pin #86. Local garage had it for a week and said there was nothing wrong with it but yet they couldnt get it to start either. i really need my van. So far you have been the best information possible. Thanks
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Hello Rowland, I have a 99 T&C Chrysler minivan. A couple of weeks ago the van died on me while I was driving down the road. The ASD relay was clicking. Have replaced the cam sensor, crank sensor, and computer, still no start no spark no fuel. I checked the coil, and the ohms are reading as per manual. Can you give me any other ideas on where to check from here or any advice. Have also replaced ignition switch and van still would not start. Thanks Aaron
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O.k. so you have replaced the ASD but you only get 3 to 4.5 V on its output wire as seen at the coil. Now that is supposed to be battery voltage. So I would pull the ASD relay and see what voltage comes in on pin 30 and pin 86 of the relay socket from fuse 17 in the PDC which is connected to the battery directly. The incoming voltage may be low (which would cause the relay to stutter). If you don't get 12v then there are a bunch of things in parallel to that relay that could be pulling down the voltage (write back and I'll tell you). If you get 12V then you need to look at all the things the ASD relay is powering to see which one is dragging down the voltage:both oxygen sensors, the generator field coil, the computer (PCM) pin 6 of black connector, the fuel injectors, and of course the coil pack. You may have to disconnect these one at a time while looking at the downstream resistance of the 87 pin of the ASD socket, but for some reason the voltage is being lost on the way to the coil pack or by being loaded by some other component in the output side of the relay.
Give that a try and if you can get 12v to the coil it will probably start.
Hi Aaron,
You said the autoshutdown relay was clicking, and so I would want to know if it might have failed? You didn't tell me which engine you have so I can't be as specific but I would look at the dark green/orange wire at the plug for the spark coil to see a couple of things: when you turn the ignition to "run" you should get 12v on that wire for about 1 second. If not then the ASD is not working or the fuse that supplied it is blown. Then if you have that squared away, when you try cranking the engine for 5 seconds you should also get 12v on the wire for as long as you crank. If not, then cam or crank sensor signal is not getting to the pcm. So start by checking those two things and let me know which engine you have. You might also try to see if you can get a fault code readout with the ignition key: "on-off-on-off-on and leave on" within an elasped time of 5 seconds or less. Then watch for message to appear in the odometer window of the instrument cluser such as a 4 digit number preceeded by a P. Let me know if anything like that appears.
Roland
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Hi Aaron,
I would like you to pull the relay and measure what voltage is showing up on pins sockets 30 and 86 as compared to ground. And if it is less than 12V then go to the fuse 17 under the dash (I don't know its label, that is not shown in the manual) and see if it also shows less than 12V on both the side that feeds the relay and the side that comes to fuse from the battery via fuse 19 in the power distribution center. I am asking you to trace back from the relay socket and find where 12v is degraded to 7.5V by the time is gets to the ASD relay socket. If it is degraded at the input to fuse 17 then please go to fuse 19 in the PDC and see what it reads on the down stream side, and then remove that fuse and see what it reads on the hot side.
Thanks,
Roland
The number 17 fuse is the fuse labeled engine correct? So do you mean pull the 17 fuse and the relay, then measure one side of fuse 17 and one side of the relay, I dont quite understand what you are asking me to try to do.
Hi Aaron,
I think you misunderstood me: the voltage supply from fuse 17 goes in parallel to pins 30 and 86 of the asd relay. So of course if you measure between them you would get 0V. So remove the relay and measure either or both as compared to ground and see if you get 12V. If you do then the ASD should not be clicking when you try the starter, but in any case you can, for a test, jumper from 30 to 87 pins which by-passes the relay and should produce 12v at the coil, injectors etc, etc. and it should start. If you don't get 12V at 86 and at 30 then we have to start examining that issue (pulling other relays). Begin by checking that you have 12V on both sides of fuse 17 and let me know what you see.
Roland
Roland
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Hi Aaron,
I am getting confused too. When you found a fuse that only had 7 volts on it, that is important. But you didn't tell me the number of the fuse, just that it was the starter fuse. There are two starter fuses: #23 in the power distribution center and #10 in the junction block under the dash. Please tell me which and is it still reading only 7V?
And did you tell me before that the fuel pump relay was clicking? or was it a different relay. When a relay clicks I suspect it is due to there being insufficient voltage on the actuator coil which in this case again is #86, so see what you read at that point. Also check what is the voltage on the circuit breaker 1 in the junction block (both contacts, please). We have to find why the voltage is only 7 on whatever fuse that is. There is a row of 10 circuit breakers on the junction block and those are significant as much as the fuses.
Also, just for the record which engine do you have.
Also, please read the resistance between the socket for pin 87 of the ASD to ground, when the ASD is removed. It will be below 1 ohm but I need to know exactly. I am suspecting that one of the wires that supplies 12v to the 2 oxygen sensor is shorted to ground. You said something about that earlier. I would suggest that you remove the plugs for the oxygen sensors, carefully, and see what happens with the starting situation. By the way, when you jumpered the ASD did the then get spark at a plug? If you didn't check, please do.
Roland
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On the question of the ignition switch:
check fuse 23 in the power distribution center to verify voltage on both sides is there when the ignition is off.
Then check fuse 10 in the junction block which you saw earlier had 7 volts, and then verify that you get 12V out of it when you try the starter. If you do, the the ignition switch is o.k. and the starter should work if you have the trans in neutral or park, of course. If you don't get 12v to fuse 10 when you try the start position with the key then the ignition switch is not closing that section properly. There are 3 other sections in that switch that might be flakey.
To check the coil, test the resistance between each of the 3 other pins and the 12V pin, it should read 0.45 to 0.65 ohms. Then remove the plug wires and measure between each pair of towers, which should be 7,000 to 15,800 ohms.
Thanks for the kind comment and evaluation and nomination.
Roland
Hi Aaron,
OK on fuse 10:when the ignition is on run it still gets power (7V) thru the 'back door' from the transcontroller, but it should jump to 12 when you try the starter, so that was a false alarm.
I am at a loss why you don't get spark when you have replaced the cam and crank sensors and you have for good measure jumped the ASD to put 12v on the coil, and the injectors. You could try jumping the fuel pump relay socket (30 to 87) and the ASD relay socket (30 to 87) and then try the starter motor and if it won't run then it pretty much has to be either the crank sensor isn't pulsing or the powertrain control module is not responding to the pulses and is then failing to put out the driver pulses to the spark coil. You could check the other three pins at the plug at the coil (the ones that don't get 12V):jumper the ASD, put the ignition in run, and then turn the engine over by hand using a wrench on the crank pulley bolt. Look at the voltage on any one of the three pins at the coil plug to see if you see it oscillate between 12V and ground as you turn the crankshaft. Each wire should pulse once per revolution of the crank. If not, then I would suspect the powertrain controller is bad. But just in case I would do the same number at the crank sensor itself: measure between the signal wire (gray/black) and the ground wire (black/light blue) with the ignition in run and turn the crank by hand and notice whether the signal voltage changes from 5 to 0.3 volts or not. Do the same on the cam sensor (tan/yellow to black/light blue). If those are pulsing, then the powertrain module I would suspect has failed.
Those are my best suggestions at this point.
Roland
AnswerHi Aaron,
As I explained in the last answer, you need to determine why you are getting only one spark. It has to be one of the following:
The cam or crank sensor is not pulsing as you crank for a full 5 seconds
The PCM is not sending driver pulses to the 3 coil wires for a full 5 seconds
The 12V supply to the coil is not present for a full 5 seconds of cranking
If all those things are ok then the coil pack has a problem.
So review my earlier answers and follow my earlier suggestions for evaluating each of those three requirements and tell me which one is not being satisfied.
Then we can narrow down the reasons for whichever one is not happening the way it is supposed to.
Roland
