PCM, Auto Shutdown Relay (ASD), or something else.
#1
09-13-2009, 04:31 PM
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PCM, Auto Shutdown Relay (ASD), or something else.
Well,
I finished putting my car back together (see https://dodgeforum.com/forum/1st-gen...lickering.html ) for that story.
Well, I am not getting any fire at the coil pack. I tested the coil pack connector wire (center Green/Orange wire with the key in the On position and show roughly ~ +20mv but not +12v as I should get). I had my dad try to "crank" the car with the test light on the two coil feeder wires (Black/Gray and Blue/Tan), nothing - not even a flicker on either one.
Since this is the first time I have ever taken off and removed the wiring harness for the rebuild, I did a continuity check all the way back to the PCM for those three wires and they all check out. So there are no problems from the PCM to the actual connectors for any of the three wires.
I know the ASD controls whether or not the Coil pack gets energy as well as energizes the fuel pump, but I have great pressure at the fuel rail, so if the ASD is sending power to the fuel pump relay, would it not also send power to the Coil pack? Where do I plug my multimeter to see if the Fuse 21 is sending +12v to the ASD and where do I check to see if +12v is comiing out of the ASD? I have a hard copy of the Haynes manual, and a software (PDF) copy of the Neon Service Manual and I am tracking down stuff even as I type this in, but if someone else already knows - great.
FYI, the engine spins up just fine. All 4 cylinders have between 185 - 190 psi compression. The coil pack primary and secondary resistance checks out on both sides (in specs), the spark plug wires resistance check out too. The system is properly timed (triple checked that one). The Crankcase position sensor is brand new. All systems were working with no PCM error codes when the car was parked (including the cam position sensor)- it just had low oil pressure due to chewed up bearings. The alternator and starter are also new. All wires and sensors are connected.
Could it be a problem with the grounding strap(s)? I never touched the one on the passenger fender side of the car, and there was a short one from the transaxle case to the transaxle case mounting point that uses two clips to secure it. It was re-installed - but could it be in the wrong place?
I finished putting my car back together (see https://dodgeforum.com/forum/1st-gen...lickering.html ) for that story.
Well, I am not getting any fire at the coil pack. I tested the coil pack connector wire (center Green/Orange wire with the key in the On position and show roughly ~ +20mv but not +12v as I should get). I had my dad try to "crank" the car with the test light on the two coil feeder wires (Black/Gray and Blue/Tan), nothing - not even a flicker on either one.
Since this is the first time I have ever taken off and removed the wiring harness for the rebuild, I did a continuity check all the way back to the PCM for those three wires and they all check out. So there are no problems from the PCM to the actual connectors for any of the three wires.
I know the ASD controls whether or not the Coil pack gets energy as well as energizes the fuel pump, but I have great pressure at the fuel rail, so if the ASD is sending power to the fuel pump relay, would it not also send power to the Coil pack? Where do I plug my multimeter to see if the Fuse 21 is sending +12v to the ASD and where do I check to see if +12v is comiing out of the ASD? I have a hard copy of the Haynes manual, and a software (PDF) copy of the Neon Service Manual and I am tracking down stuff even as I type this in, but if someone else already knows - great.
FYI, the engine spins up just fine. All 4 cylinders have between 185 - 190 psi compression. The coil pack primary and secondary resistance checks out on both sides (in specs), the spark plug wires resistance check out too. The system is properly timed (triple checked that one). The Crankcase position sensor is brand new. All systems were working with no PCM error codes when the car was parked (including the cam position sensor)- it just had low oil pressure due to chewed up bearings. The alternator and starter are also new. All wires and sensors are connected.
Could it be a problem with the grounding strap(s)? I never touched the one on the passenger fender side of the car, and there was a short one from the transaxle case to the transaxle case mounting point that uses two clips to secure it. It was re-installed - but could it be in the wrong place?
#2
09-14-2009, 11:18 AM
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Update
I took the bottom off the Power Distribution Center (PDC) and found the connection where the Green/Orange wire comes out going to the PCM and checked for continuity from there all the way to the coil pack connector and it was fine.
When I checked the voltage level (key in On position) at that point in the PDC, nada. Bad ASR relay? I even went and turned the key off then on again and quickly read the voltage again - nada. My red probe was on the green/orange wire connector while the black probe was on the negative battery terminal. I state this because maybe my probe placement is wrong, and if so, where should they be?
I read somewhere that if the PCM senses the car is not cranking, it will shut off the ASR - thereby shutting off the coil pack, but how long does that take?
Can the Dodge dealer checkout a PCM that has been removed from the car?
Does anyone know how to check out the Fuel and ASR relays with a multimeter? Or should I just let the dealer check it out - or can they?
When I checked the voltage level (key in On position) at that point in the PDC, nada. Bad ASR relay? I even went and turned the key off then on again and quickly read the voltage again - nada. My red probe was on the green/orange wire connector while the black probe was on the negative battery terminal. I state this because maybe my probe placement is wrong, and if so, where should they be?
I read somewhere that if the PCM senses the car is not cranking, it will shut off the ASR - thereby shutting off the coil pack, but how long does that take?
Can the Dodge dealer checkout a PCM that has been removed from the car?
Does anyone know how to check out the Fuel and ASR relays with a multimeter? Or should I just let the dealer check it out - or can they?
#3
09-16-2009, 10:39 AM
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According to the manual when the key is in the ON positions, the Orange wire coming out of the PCM is supposed to have 8-9 volts. This wire feeds the Vehicle Speed Sensor (VSS), the Crankshaft Position Sensor (CPS), and the Camshaft Position Sensor (CMPS).
These are the sensors that tell the PCM to open the ASR relay (and since it is on the same circuit, the fuel relay) and feed +12v to the Gr/Or wire going to the coil pack. Is that correct?
I did find that I was not getting any voltage to the CMPS, but did get the proper voltage to the CPS and VSS sensors. I took out the entire wiring harness, did a continuity check between the PCM connector and the CMPS connector, and found that there was a break! Yea! Not..... Now I get the proper voltage to the CMPS, but still no fire.
Why did I take out the entire harness? Well, I was tired of bending over the engine compartment, and it made it easier to just check the whole harness with a continuity check. The CMPS sensor connector was the only one I had an issue with.
These are the sensors that tell the PCM to open the ASR relay (and since it is on the same circuit, the fuel relay) and feed +12v to the Gr/Or wire going to the coil pack. Is that correct?
I did find that I was not getting any voltage to the CMPS, but did get the proper voltage to the CPS and VSS sensors. I took out the entire wiring harness, did a continuity check between the PCM connector and the CMPS connector, and found that there was a break! Yea! Not..... Now I get the proper voltage to the CMPS, but still no fire.
Why did I take out the entire harness? Well, I was tired of bending over the engine compartment, and it made it easier to just check the whole harness with a continuity check. The CMPS sensor connector was the only one I had an issue with.
#4
09-16-2009, 10:53 AM
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According to the manual when the key is in the ON positions, the Orange wire coming out of the PCM is supposed to have 8-9 volts. This wire feeds the Vehicle Speed Sensor (VSS), the Crankshaft Position Sensor (CPS), and the Camshaft Position Sensor (CMPS).
These are the sensors that tell the PCM to open the ASR relay (and since it is on the same circuit, the fuel relay) and feed +12v to the Gr/Or wire going to the coil pack. Is that correct?
I did find that I was not getting any voltage to the CMPS, but did get the proper voltage to the CPS and VSS sensors. I took out the entire wiring harness, did a continuity check between the PCM connector and the CMPS connector, and found that there was a break! Yea! Not..... Now I get the proper voltage to the CMPS, but still no fire.
Why did I take out the entire harness? Well, I was tired of bending over the engine compartment, and it made it easier to just check the whole harness with a continuity check. The CMPS sensor connector was the only one I had an issue with.
The fuel system has pressure and there is fuel in the fuel rail. When I turn the key to the on position, the fuel pump kicks in for just a second or two.
No PCM error codes (ODB-II code reader), no codes doing the ON OFF key dance except for 12 and 55 - which are normal.
My horn works, so I tried the relay from it in place of the ASR one - no change, I even put the ASR relay in the horn location - works. I believe that should eliminate the relay as the issue.
What I am hoping for is someone out there who may know what I can check next. When I turn the key to the ON position, should the Gr/Or wire coming out of the ASR circuit have +12v at that time - or when?
BTW, I found out the hard way that Dealers can check PCM's ONLY while attached to the car! Unbelievable! They do not have PCM test beds to use like computer manufacturers do for their components, so the only way I can determine if this is a PCM problem is to have my car towed to place where they can check it out, and since my car is a 1995 model with a 5-speed, the only PCM that works is one made for a 1995 with a 5-speed. Double-darn. Just not a whole lot of them left to find in a local junk yard, and I hate to buy one just to find out that may not have been the problem.
I am rapidly running out of ideas here.
These are the sensors that tell the PCM to open the ASR relay (and since it is on the same circuit, the fuel relay) and feed +12v to the Gr/Or wire going to the coil pack. Is that correct?
I did find that I was not getting any voltage to the CMPS, but did get the proper voltage to the CPS and VSS sensors. I took out the entire wiring harness, did a continuity check between the PCM connector and the CMPS connector, and found that there was a break! Yea! Not..... Now I get the proper voltage to the CMPS, but still no fire.
Why did I take out the entire harness? Well, I was tired of bending over the engine compartment, and it made it easier to just check the whole harness with a continuity check. The CMPS sensor connector was the only one I had an issue with.
The fuel system has pressure and there is fuel in the fuel rail. When I turn the key to the on position, the fuel pump kicks in for just a second or two.
No PCM error codes (ODB-II code reader), no codes doing the ON OFF key dance except for 12 and 55 - which are normal.
My horn works, so I tried the relay from it in place of the ASR one - no change, I even put the ASR relay in the horn location - works. I believe that should eliminate the relay as the issue.
What I am hoping for is someone out there who may know what I can check next. When I turn the key to the ON position, should the Gr/Or wire coming out of the ASR circuit have +12v at that time - or when?
BTW, I found out the hard way that Dealers can check PCM's ONLY while attached to the car! Unbelievable! They do not have PCM test beds to use like computer manufacturers do for their components, so the only way I can determine if this is a PCM problem is to have my car towed to place where they can check it out, and since my car is a 1995 model with a 5-speed, the only PCM that works is one made for a 1995 with a 5-speed. Double-darn. Just not a whole lot of them left to find in a local junk yard, and I hate to buy one just to find out that may not have been the problem.
I am rapidly running out of ideas here.
#5
09-17-2009, 05:45 PM
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Well, don't know if anyone out there gives a rip, but when I am trying to diagnose my issues and see a half-completed thread, it burns my cookies, so for those out there who MAY in the future read these words, I hope these notes help.
Today, I have done the following:
1) I did a continuity check from the ASD relay out (the Green/Orange wire on the underside of the PDC) all the way to the coil pack center wire connector - no problem there. Just wanted to make sure that IF the ASD were to output +12 volts, it would get there. Turned the key to the on position and still no voltage either at the coil pack connector, OR at the ASD relay. I saw one thread where person said they only got a 12 volt reading with someone trying to "crank" the car, but they were having issues with the car running rough, not no spark, and I have not yet tried that.
2) I disconnected and removed the Camshaft Position Sensor (CPS) from the cylinder head. I took the back of the connector apart and removed the rubber plug to gain access to the pins. This is the connector where I had the wire break and I fixed it BTW).
With the sensor in my hand and connected, I turned the key on, put the red probe on the Orange wire and saw 8.99 volts - good. I then put the probe on the Yellow/Tan wire (output wire to PCM) and waved my part pickup magnet at the sensor in a circular manner - REAL slow. When the magnet got near the sensor - the readout changed to +5.07v. When I moved the magnet away from the sensor, it dropped to a level just above 5 millivolts. ~ 6.6 millivolts.
Now unless I am an idiot, those readings are within the specified range of a completely functional CPS Please let me know if I am wrong.
Well, I buttoned that all back up, reconnected the coil pack wire, and just for the halibut, tried to crank it - knowing it would not - but what the hey. Then, when I had tried 3 times for about 6 seconds each time, I did the 3 step Key Dance = On - Off - On - Off - On within 5 seconds and this time I got the infamous 11 code (along with 12 and 55 of course).
I found a previous posting (hey to 95to96transplantneon) that showed what codes are associated with error 11 (even though these other codes did not show up on my ODB-II reader) when I checked it too.
Error Code 11
P0320 No Crankshaft Reference Signal At PCM
If this is the possible problem, then I guess I need to crawl back under my car pull out the CKPS and do the same checks on it as I did for the CPS. The orange wire should have between 8-9volts (which an earlier check confirmed but I will repeat), and I should be able to wave a big flat screwdriver at the sensor end with my probe on the Blue/gray wire to see it fluctuate between 5mv and 5v as the manual says if it is functional.
P1390 Timing Belt Skipped Tooth
I just finished quadruple-checking the timing. I put the #1 cylinder on TDC (checked by removing the spark plug and putting a thin metal shaft down the hole) and pulling the check hole plug on the timing belt housing and confirming that the camshaft mark lines up perfectly with the mark on the cover. This is AFTER trying to crank the engine many, many times, so if the timing were off by even a 1/2 tooth, the marks would not line up and this should have shown up by now. This is not the problem.
P1391 Intermittent Loss Of CKPS Or CPS
The only thing I can think of that could cause the intermittent loss of a sensor that checks out to be in spec, would be the voltage going to the sensor getting dropped. What could cause this? Bad PCM? Partly faulty ASD relay? I did the swap the horn relay for the ASD one, so that should not be the problem. Are we back to a bad PCM then? Of course, this is assuming that my checkout of the CKPS reveals no issues there - and since it is brand new, it should be OK.
P1398 Misfire Adaptive Numerator At Limit
What the heck is this? Does this mean that the computer counts misfires and when the computer limit for a number it can store has been reached and can't count any more that it throws out this error? Kind of makes sense, but I don't have that error code in my PCM anyway - so I kind of doubt this is the issue I am having. Mainly because I am getting NO fire, not some or bad fire.....
OK, because I now have an error code 11, that SHOULD be the indicator as to why I get no fire at the coil pack. Now assuming that my check of the CKPS turns out OK, AND the fact that I have checked out almost every other wire and sensor that could play a part, AND changed out the ASD relay with my horn relay - would that then by almost by definition indicate a flakey/bad PCM?
The idea of tossing money at a new/reman/used PCM just to find out that it is not the issue just burns my cookies. Can other repair facilities besides the dealer DEFINITIVELY diagnose a bad PCM? I mean hey, I can play the parts swap game just like a good grease monkey.....
Today, I have done the following:
1) I did a continuity check from the ASD relay out (the Green/Orange wire on the underside of the PDC) all the way to the coil pack center wire connector - no problem there. Just wanted to make sure that IF the ASD were to output +12 volts, it would get there. Turned the key to the on position and still no voltage either at the coil pack connector, OR at the ASD relay. I saw one thread where person said they only got a 12 volt reading with someone trying to "crank" the car, but they were having issues with the car running rough, not no spark, and I have not yet tried that.
2) I disconnected and removed the Camshaft Position Sensor (CPS) from the cylinder head. I took the back of the connector apart and removed the rubber plug to gain access to the pins. This is the connector where I had the wire break and I fixed it BTW).
With the sensor in my hand and connected, I turned the key on, put the red probe on the Orange wire and saw 8.99 volts - good. I then put the probe on the Yellow/Tan wire (output wire to PCM) and waved my part pickup magnet at the sensor in a circular manner - REAL slow. When the magnet got near the sensor - the readout changed to +5.07v. When I moved the magnet away from the sensor, it dropped to a level just above 5 millivolts. ~ 6.6 millivolts.
Now unless I am an idiot, those readings are within the specified range of a completely functional CPS Please let me know if I am wrong.
Well, I buttoned that all back up, reconnected the coil pack wire, and just for the halibut, tried to crank it - knowing it would not - but what the hey. Then, when I had tried 3 times for about 6 seconds each time, I did the 3 step Key Dance = On - Off - On - Off - On within 5 seconds and this time I got the infamous 11 code (along with 12 and 55 of course).
I found a previous posting (hey to 95to96transplantneon) that showed what codes are associated with error 11 (even though these other codes did not show up on my ODB-II reader) when I checked it too.
Error Code 11
P0320 No Crankshaft Reference Signal At PCM
If this is the possible problem, then I guess I need to crawl back under my car pull out the CKPS and do the same checks on it as I did for the CPS. The orange wire should have between 8-9volts (which an earlier check confirmed but I will repeat), and I should be able to wave a big flat screwdriver at the sensor end with my probe on the Blue/gray wire to see it fluctuate between 5mv and 5v as the manual says if it is functional.
P1390 Timing Belt Skipped Tooth
I just finished quadruple-checking the timing. I put the #1 cylinder on TDC (checked by removing the spark plug and putting a thin metal shaft down the hole) and pulling the check hole plug on the timing belt housing and confirming that the camshaft mark lines up perfectly with the mark on the cover. This is AFTER trying to crank the engine many, many times, so if the timing were off by even a 1/2 tooth, the marks would not line up and this should have shown up by now. This is not the problem.
P1391 Intermittent Loss Of CKPS Or CPS
The only thing I can think of that could cause the intermittent loss of a sensor that checks out to be in spec, would be the voltage going to the sensor getting dropped. What could cause this? Bad PCM? Partly faulty ASD relay? I did the swap the horn relay for the ASD one, so that should not be the problem. Are we back to a bad PCM then? Of course, this is assuming that my checkout of the CKPS reveals no issues there - and since it is brand new, it should be OK.
P1398 Misfire Adaptive Numerator At Limit
What the heck is this? Does this mean that the computer counts misfires and when the computer limit for a number it can store has been reached and can't count any more that it throws out this error? Kind of makes sense, but I don't have that error code in my PCM anyway - so I kind of doubt this is the issue I am having. Mainly because I am getting NO fire, not some or bad fire.....
OK, because I now have an error code 11, that SHOULD be the indicator as to why I get no fire at the coil pack. Now assuming that my check of the CKPS turns out OK, AND the fact that I have checked out almost every other wire and sensor that could play a part, AND changed out the ASD relay with my horn relay - would that then by almost by definition indicate a flakey/bad PCM?
The idea of tossing money at a new/reman/used PCM just to find out that it is not the issue just burns my cookies. Can other repair facilities besides the dealer DEFINITIVELY diagnose a bad PCM? I mean hey, I can play the parts swap game just like a good grease monkey.....
#6
09-18-2009, 10:11 AM
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It lives!!!
Well,
I wish I had a dime for every time I just "*** u me d" that "it just couldn't be that......."
The Cranshaft Position Sensor WAS bad. I bought a brand new one about 6 months ago when I rebuilt the engine the first time, so I *** u me d that there was no way it was the problem. It was.
Last night, I finally decided that since I had checked damn near everything else sensor and circuit wise that you can check, I crawled up under the car, rechecked the sensor to make sure it was getting the requisite 8-9v of power and then proceeded to pull the back of the sensor connector cover off, pull back the rubber plug and back-probe the connector Blue/Grey wire with the sensor connected and the key still ON.
I then waved the sensor near the engine block (the magnet is inside the sensor BTW unlike the cam sensor that uses the magnet on the camshaft instead) and the readings DID NOT vary from the +5v to 5 mv as it should.
I took the sensor back to O'Reillys, got a new one (yea Lifetime Warranty!!), put it on, checked again - and this time, each time I waved the sensor near the engine, you could hear the fuel pump relay and ASD relays kick on and off - good sign and the readings were correct, so I buttoned it up, crawled in the car, and fired it up first time!
I drove a victory lap last night...... So far so good!
I wish I had a dime for every time I just "*** u me d" that "it just couldn't be that......."
The Cranshaft Position Sensor WAS bad. I bought a brand new one about 6 months ago when I rebuilt the engine the first time, so I *** u me d that there was no way it was the problem. It was.
Last night, I finally decided that since I had checked damn near everything else sensor and circuit wise that you can check, I crawled up under the car, rechecked the sensor to make sure it was getting the requisite 8-9v of power and then proceeded to pull the back of the sensor connector cover off, pull back the rubber plug and back-probe the connector Blue/Grey wire with the sensor connected and the key still ON.
I then waved the sensor near the engine block (the magnet is inside the sensor BTW unlike the cam sensor that uses the magnet on the camshaft instead) and the readings DID NOT vary from the +5v to 5 mv as it should.
I took the sensor back to O'Reillys, got a new one (yea Lifetime Warranty!!), put it on, checked again - and this time, each time I waved the sensor near the engine, you could hear the fuel pump relay and ASD relays kick on and off - good sign and the readings were correct, so I buttoned it up, crawled in the car, and fired it up first time!
I drove a victory lap last night...... So far so good!
#7
09-09-2010, 08:23 PM
Dude,
What a great thread. I am having the exact same issue after getting my motor back in after pulling it to do some work (PaceSetter LTH, HiFlow Cat, Ed P Racing Head, Ported intake, PT Clutch, Gates timing belt, Gates Mechanical Tensioner, Odessey Mini Battery). I know you were not getting any replies so it is hard to know if posting was useful, but I printed it out and will be using it to diagnose this weekend.
One question - Where did you get the PDF copy of the Neon Service Manual? Like you I have the Haynes, but it does not have much of this stuff in it.
Thanks,
Sammer
What a great thread. I am having the exact same issue after getting my motor back in after pulling it to do some work (PaceSetter LTH, HiFlow Cat, Ed P Racing Head, Ported intake, PT Clutch, Gates timing belt, Gates Mechanical Tensioner, Odessey Mini Battery). I know you were not getting any replies so it is hard to know if posting was useful, but I printed it out and will be using it to diagnose this weekend.
One question - Where did you get the PDF copy of the Neon Service Manual? Like you I have the Haynes, but it does not have much of this stuff in it.
Thanks,
Sammer
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#8
09-10-2010, 10:29 AM
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I actually bought it from a guy on eBay. However, after I bought it, the guy was completely shutdown and I believe he was selling it illegally - personal opinion, not fact - but I have not seen anyone else selling one lately on eBay, but you can look there and see.
#9
09-10-2010, 03:15 PM
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#10
09-10-2010, 03:26 PM
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1 year and still going strong
I just noticed that in one week, it will have been a year since I got my car engine rebuilt for the second time and back on the road! I have put almost 20000 miles on the car and am getting about 35 to 36 mpg now. All gremlins have been exorcised....
Lovin' every minute of it!
Lovin' every minute of it!