2000 Ram Van 3500 - Crank but won't start
#1
2000 Ram Van 3500 - Crank but won't start
My flippin sweet van ( Named Vincent ) had an instant ability to crank but not start. I get P-0351 error code, and check engine light, ABS light and brake light while it fails to start.
Having done much troubleshooting and research, I've tried many things, so let me explain what I've done and what I know :
Starter engages, and strong crank, but no start. I've replaces the ignition coil first, as I was not getting spark. After replacement, I realized that I'm not getting voltage to the ignition coil, so the coil replacement was not necessary. I noticed at this point too, that I was not getting fuel ( pretty sure ).
Chasing the problem further, I realize that the Automatic Shutdown Relay ( ASR ) is not engaging. I was able to test I do get voltage to the coil of the relay, but not engaging. So I replace the relay, but no difference. Upon further investigation, I get voltage to the relay, but the ground portion of the relay's coil is not set to ground ( the Power Train Control Module sinks that to ground ). I decided to jumper the relay closed, and several other relays engaged, and now I believe I also am getting fuel, but still no start.
I replaced the ignition switch 1 year ago, however I've not ruled that out as the problem. It seems to me that the computer is missing an input, to tell it to sink the ground on the Automatic Shutdown Relay & likely to sink the ignition coil to create spark.
What should I try next? Can I test that the Powertrain Control Module ( PCM ) has all the signals it needs to sink the Automatic Shutdown Relay? Can I test that the PCM is sinking the coil, to create spark properly? Should the PCM sink the ASR before I crank, or during the cranking process ( For instance it sinks after getting an input during crank vs. should sink to ground with ignition switch engaged )
In looking at the diagram, makes me wonder if the crank sensor is not sending signal to the PCM, but unsure how to verify that idea. However if the PCM sinks the ASR prior to crank, that would throw out that idea.
Other thoughts?
Having done much troubleshooting and research, I've tried many things, so let me explain what I've done and what I know :
Starter engages, and strong crank, but no start. I've replaces the ignition coil first, as I was not getting spark. After replacement, I realized that I'm not getting voltage to the ignition coil, so the coil replacement was not necessary. I noticed at this point too, that I was not getting fuel ( pretty sure ).
Chasing the problem further, I realize that the Automatic Shutdown Relay ( ASR ) is not engaging. I was able to test I do get voltage to the coil of the relay, but not engaging. So I replace the relay, but no difference. Upon further investigation, I get voltage to the relay, but the ground portion of the relay's coil is not set to ground ( the Power Train Control Module sinks that to ground ). I decided to jumper the relay closed, and several other relays engaged, and now I believe I also am getting fuel, but still no start.
I replaced the ignition switch 1 year ago, however I've not ruled that out as the problem. It seems to me that the computer is missing an input, to tell it to sink the ground on the Automatic Shutdown Relay & likely to sink the ignition coil to create spark.
What should I try next? Can I test that the Powertrain Control Module ( PCM ) has all the signals it needs to sink the Automatic Shutdown Relay? Can I test that the PCM is sinking the coil, to create spark properly? Should the PCM sink the ASR before I crank, or during the cranking process ( For instance it sinks after getting an input during crank vs. should sink to ground with ignition switch engaged )
In looking at the diagram, makes me wonder if the crank sensor is not sending signal to the PCM, but unsure how to verify that idea. However if the PCM sinks the ASR prior to crank, that would throw out that idea.
Other thoughts?
Last edited by Flippinsweetdude; 10-23-2022 at 07:25 PM.
#2
#3
I don't get ASD nor the fuel relay for the initial 3 seconds. Looks like they are connected on both the ignition switch ( for positive ) and sinked to ground with the PCM.
I just tried to force the ASR coil to ground, and it does engage the relay, and I get voltage at the ignition coil ( pin 1 ), same as when I jumper-ed the relay. So I'm confident the PCM is not sinking the coil relay to ground, when key is in ON position.
Last edited by Flippinsweetdude; 10-23-2022 at 09:16 PM.
#4
I have nearly all the same symptoms as this thread ( other than It has never started when cold ).
https://dodgeforum.com/forum/dodge-r...ml#post2228452
Perhaps I'll pull the wires from the alternator, and see if ASR gets a good circuit
https://dodgeforum.com/forum/dodge-r...ml#post2228452
Perhaps I'll pull the wires from the alternator, and see if ASR gets a good circuit
#5
ASD relay will only power things for a few seconds, unless the PCM sees the engine turning. (crank sensor.) If the ASD isn't re-engaged when the engine is cranking, (and the fuel pump should be running as well.) Probably a bad crank sensor, or the wiring between it, and the PCM. If you decide to replace the sensor, use ONLY a genuine mopar sensor. The dodge systems really don't care for the aftermarket sensors.
#6
ASD relay will only power things for a few seconds, unless the PCM sees the engine turning. (crank sensor.) If the ASD isn't re-engaged when the engine is cranking, (and the fuel pump should be running as well.) Probably a bad crank sensor, or the wiring between it, and the PCM. If you decide to replace the sensor, use ONLY a genuine mopar sensor. The dodge systems really don't care for the aftermarket sensors.
I just noticed that while cranking, my voltage goes down significantly ( on the dashboard meter/indicator ). It goes from 12v down to 9v really quick. So going to charge the battery ( less than year old ) up overnight, and pursue the alternator is grounding out the system next.
Last edited by Flippinsweetdude; 10-23-2022 at 09:09 PM.
#7
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#8
So, I am getting good voltage from the ignition switch and I am getting good initial ground sink from the PCM to the relay. The relay does engage for approx 2 seconds then releases.
This makes me think ( from other forums and my diagrams ) that I'm missing input from a sensor back to the PCM to re-engage the relay. From what I can see the crank sensor is likely my next part to replace.
#10