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Author Topic: 94 5.9 No Start.....PCM Diagnosis?(FIXED!!!)  (Read 8971 times)

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Offline kawgomoo

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94 5.9 No Start.....PCM Diagnosis?(FIXED!!!)
« on: May 7, 2010, 09:51:43 PM »
94 5.9 Magnum out of a Van.

When key is turned to "run" everything pwers up 2 seconds, then all 8 injectors Click once and the power turns off.

By powering on and off i am reffering to the status of ASD relay and fuel pump.

When engine is cranked over, ASD briefly triggers on and turns back off immediately. Subsequent attempts to crank engine will not cause the computer to trigger the relay again UNTIL full power cycle. i.e. once the key has been turned off fully and back on.

cmp sensor tests normal as per haynes manual. 5v on signal wire with rotor facing firewall, 0 volts the other way. voltage hops 0-5 while cranking.

ckp sensor - cannot find a test for this sensor other than to use a scope. i dont have one, and the engine wont start anyways sooooo...yeah. i did try a new CKP sensor from the parts store and it made no difference.

The coil has power, but never seems to get signal to fire from the PCM. Coil bench tests good, and fires a plug when coil - wire is tapped to ground.

My only thought is the PCM is shot, or i dont have something wired up correctly.

I have batt + power going to pins 9,3,57.

Pin 51, asd relay is controlling my fuel pump relay, and idiot light to let me know when the computer is shutting down.

Any thoughts here?  Can i take the ecu to the dealer and have them bench test it? I know at Honda we have a breakout box for testing ecu's off the vehicle...i assume dodge has the same sort of device?
« Last Edit: May 8, 2010, 07:54:14 PM by kawgomoo »

Offline atowinram

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Re: 94 5.9 No Start.....PCM Diagnosis?
« Reply #1 on: May 7, 2010, 09:57:58 PM »
If you have a local NAPA store, call and see if they have a tester with the plug to match your computer.  We have one at our store that can read several of them.
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Offline s ǝoɾ

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Re: 94 5.9 No Start.....PCM Diagnosis?
« Reply #2 on: May 7, 2010, 09:58:21 PM »
CKP is VR (I think, 2 wires?).....so it is simple AC voltage generator. Generator types produce around .5VAC+ at cranking speeds, and generally have a resistance from 200ohm-1500ohm. That is general broad overview of all VR types. May have some kind of airgap between the CKP and that flex plate tone ring.

You do have the tone ring on there, right?

Even if dodge did make a BOB (havent found it listed) it would have long since been thrown out. We are talking about a system last made 15 years ago. Sure 5 years ago they may have seen an occasional obd1 truck come in, but rest assure, there aint many taking 15 year old dodges into the dealer.

It's not going to do anything until it gets a crank pulse.
Avoid replacing any part that you have not proven to be faulty through extensive testing.

Offline DODGEBOYS

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Re: 94 5.9 No Start.....PCM Diagnosis?
« Reply #3 on: May 8, 2010, 05:14:45 AM »
Vehicle Application: 1994 Dodge B250 Sportsman 5.9L, Vin Z, Eng Cfg V8 
 
Customer Concern: Cranks no start, no spark, no injector pulse, no scan tool communication. 
Tests/Procedures: 1. Check the power supplies to the Powertrain Control Module (PCM) on the Red wire at pin 3 and the Dark Blue wire at pin 9.

2. If no power on pin 9, check the fusible links behind the battery. The ignition switch gets power from the Red wire. the Red wire gets power from an Orange fusible link located near the battery.

3. If the Red wire at the ignition switch has power, check for a bad ignition switch. The Dark Blue wire gets power at key on. 
Potential Causes: Burnt Fusible Link
Wiring
 
Diagnostic Codes: None 
 
Average Reported Mileage: 201633 
 
 
 
Confirmed Fix Summary   
 
 Confirmed Fix 1 -  Ignition Switch Wiring
 
 
 
Confirmed Fix Details   
 
Tech   Reported Fix Details  Confirmed Fix

June 17, 2009   1994 Dodge B250, Sportsman 5.9L, Vin Z, Eng Cfg V8 *
Repaired Ignition Switch Wiring
201,633 miles  Ignition Switch Wiring 
 
 
put your truck info HERE
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Offline DODGEBOYS

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Re: 94 5.9 No Start.....PCM Diagnosis?
« Reply #4 on: May 8, 2010, 05:16:57 AM »
Vehicle Application: 1993 Dodge D250 5.9L, GAS, Vin Z, Eng Cfg V8 1994 Dodge Ram 2500 5.9L, GAS, Vin Z, Eng Cfg V8
1994 Dodge Ram 1500 5.9L, Vin Z, Eng Cfg V8 
 
Customer Concern: No start, no power at the fuel pump during cranking. 
Tests/Procedures: 1. Check the ATM test on the fuel pump relay with a scan tool.

2. Remove the fuel pump relay from the PDC and jump cavity 30 to 87. Check if the fuel pump will run. If not, check for an open wire to the fuel pump.

3. Check for power at the pump connector with the PDC terminals jumped. 
Potential Causes: Fuel Pump Relay
Wiring Harness
 
Diagnostic Codes: None 
 
Average Reported Mileage: 147515 
 
 
 
Confirmed Fix Summary   
 
 Confirmed Fix 1 -  Fuel Pump Relay Wiring
 
 
 
Confirmed Fix Details   
 
Tech   Reported Fix Details  Confirmed Fix

August 19, 2009   1993 Dodge D250, 5.9L, GAS, Vin Z, Eng Cfg V8 *
Repaired Fuel Pump Relay Wiring Corroded wire between the relay and the computer that needed to be cleaned.
85,243 miles 
 
 
put your truck info HERE
MOPAR TO YA! AARON HOWORD TOWNSEND / SLANTEDMIND---GOD BLESSDODGEBOYS FSM STORE
ramchargercentral@hotmail.com
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Re: 94 5.9 No Start.....PCM Diagnosis?
« Reply #5 on: May 8, 2010, 05:20:39 AM »
Vehicle Application: 1994 Dodge Ram 2500 5.9L, GAS, Vin Z, Eng Cfg V8 1994 Dodge Ram 2500 8.0L, GAS, Vin W, Eng Cfg V10
 
Customer Concern: The engine cranks but will not start. It has no spark or fuel injector pulse. 
Tests/Procedures: 1. Monitor the voltage on the Orange wire that supplies 8-9 volts to the Camshaft Position (CMP) sensor, the Crankshaft Position (CKP) sensor and the Vehicle Speed Sensor (VSS).

2. If the voltage drops below 7 volts when it stalls, check the B+ feeds to the Powertrain Control Module (PCM) on the Red/White wire at pin 3 and the Light Green/Black wire at pin 9.

3. If the B+ feeds are OK, unplug the VSS to see if the problem is gone.

4. If the problem is not gone, cut the Orange wire near the PCM and feed the sensor side of the cut Orange wire with B+ through a test light. The sensors will operate OK when powered up this way, and if shorting out, the test light will light up. 
Potential Causes: Camshaft Position Sensor (CMP)
Crankshaft Position (CKP) Sensor
Manifold Absolute Pressure (MAP) Sensor
Powertrain Control Module (PCM)
Throttle Position Sensor (TPS)
Vehicle Speed Sensor (VSS)
Wiring
 
Tech Tips: Cutting the Orange wire verifies a problem external of the PCM. Found 8v Orange wire at VSS to be corroded and drawing down the voltage 
put your truck info HERE
MOPAR TO YA! AARON HOWORD TOWNSEND / SLANTEDMIND---GOD BLESSDODGEBOYS FSM STORE
ramchargercentral@hotmail.com
DO NOT use the site IM,s to contact me  l have them turned OFF

Offline kawgomoo

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Re: 94 5.9 No Start.....PCM Diagnosis?
« Reply #6 on: May 8, 2010, 07:46:35 AM »
CKP is 3 wires,  is hall effect sensor. 

I dont know why any dealer would through away a break out box. At honda we get 20 year old cars in there for service all the time. You would be amazed how many little old ladies still take there '85 accord to the dealer for its regular scheduled maintenance. Of course the american car companies work a little differently.

CKP is VR (I think, 2 wires?).....so it is simple AC voltage generator. Generator types produce around .5VAC+ at cranking speeds, and generally have a resistance from 200ohm-1500ohm. That is general broad overview of all VR types. May have some kind of airgap between the CKP and that flex plate tone ring.

You do have the tone ring on there, right?

Even if dodge did make a BOB (havent found it listed) it would have long since been thrown out. We are talking about a system last made 15 years ago. Sure 5 years ago they may have seen an occasional obd1 truck come in, but rest assure, there aint many taking 15 year old dodges into the dealer.

It's not going to do anything until it gets a crank pulse.

Offline kawgomoo

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Re: 94 5.9 No Start.....PCM Diagnosis?
« Reply #7 on: May 8, 2010, 07:57:01 AM »
There is power on pin 3 and 9. No PDC is installed, this is just a motor and wiring harness sitting on the ground. PDC is gone, key switch is gone. I am hot wiring directly off the engine harness, tracing pins back from the ecu plug.

Dark Blue Pin 9 is connected directly to battery.
Pin 3 is ign wire, also direct to battery.
pin57 ASD Sense. dg/or i believe. This is also ran to 12v off the battery.

Pin 51 is ASD Relay output. This is the wire im watching to verify ECU status. When you turn on the "key" the ecu comes on, does its 2 second deal. Fires all 8  injectors and turns back off waiting crank signal.

Changing CKP Sensor...No help.

Tried unplugging each sensor and then cranking engine to test for  bad sensor grounding out...No change.

All sensors have 5v reference while cranking.

Battery voltage does not drop below 10v while cranking.

The Transmission section of the ENGINE HARNESS has been CUT OFF!!! I did not cut this, is there any wires running down towards the tranny that may cause a failure to start if not connected? or not seeing a sensor? I cant imagine a VSS having that kind of authority though.

I will post some pictures this afternoon of what i got, hopefully i can get this thing figured out.

Right now im leaning towards a bad ECU....But have no freaking way to test it!



Vehicle Application: 1994 Dodge B250 Sportsman 5.9L, Vin Z, Eng Cfg V8 
 
Customer Concern: Cranks no start, no spark, no injector pulse, no scan tool communication. 
Tests/Procedures: 1. Check the power supplies to the Powertrain Control Module (PCM) on the Red wire at pin 3 and the Dark Blue wire at pin 9.

2. If no power on pin 9, check the fusible links behind the battery. The ignition switch gets power from the Red wire. the Red wire gets power from an Orange fusible link located near the battery.

3. If the Red wire at the ignition switch has power, check for a bad ignition switch. The Dark Blue wire gets power at key on. 
Potential Causes: Burnt Fusible Link
Wiring
 
Diagnostic Codes: None 
 
Average Reported Mileage: 201633 
 
 
 
Confirmed Fix Summary   
 
 Confirmed Fix 1 -  Ignition Switch Wiring
 
 
 
Confirmed Fix Details   
 
Tech   Reported Fix Details  Confirmed Fix

June 17, 2009   1994 Dodge B250, Sportsman 5.9L, Vin Z, Eng Cfg V8 *
Repaired Ignition Switch Wiring
201,633 miles  Ignition Switch Wiring 
 
 


Offline kawgomoo

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Re: 94 5.9 No Start.....PCM Diagnosis?
« Reply #8 on: May 8, 2010, 07:57:58 AM »
triple post!!!! lol

If anyone out there has a FSM for 94, can you tell me if there is a bench test for the ckp and cmp sensor? 

Offline s ǝoɾ

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Re: 94 5.9 No Start.....PCM Diagnosis?
« Reply #9 on: May 8, 2010, 08:05:29 AM »
CKP is 3 wires,  is hall effect sensor.  

I dont know why any dealer would through away a break out box. At honda we get 20 year old cars in there for service all the time. You would be amazed how many little old ladies still take there '85 accord to the dealer for its regular scheduled maintenance. Of course the american car companies work a little differently.


You be amazed how cheap-ass most dodge owners are when it comes to dealer services....

I still haven't dug through those thousands of pages yet to find your diagrams.   :-\

Do you own a logic probe? That's the fastest way to test a CKP (on engine)

Next way is multimeter on sig wire and turning engine over by hand as you watch the 36-1 tone ring. Should go "high" (5v) at each tooth, then "low" (0v) between the 2. Cranking at starter speed will end up with a whir of mixed numbers and no distinct fluctuations. Logic probe is easier because even at cranking speed you can watch LED blink, and some even use a 3rd LED to indicate a pulsed signal like that of a hall effect digital sensor.

Same applies for CMP distributor.

Actually, it may be 8v, not 5v, I think 5v came with obd2. Ok ok, I'll go look.
Avoid replacing any part that you have not proven to be faulty through extensive testing.

Offline kawgomoo

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Re: 94 5.9 No Start.....PCM Diagnosis?
« Reply #10 on: May 8, 2010, 08:19:32 AM »
the haynes manual describes a test with the multi meter watching the voltage rise and fall on the CMP sensor, which i did and it does.

However, there is no test outlined for testing the CKP sensor. I tried watching for signal with the meter, but i am not seeing any voltage fluctuation as i crank the motor around.

The ckp sensor does have voltage on its reference wire however.

No logic tester here...Sounds handy for situation like this.

Lastly, since my FSM is for an 89, it does not cover the CKP sensor at all.

Oh yeah, tone ring has 8 windows, it is not a 36-1 ring like you would see on a ford edis.

it uses the 8 windows, and the cmp sensor in series to tell it when #1 is on compression
« Last Edit: May 8, 2010, 08:21:16 AM by kawgomoo »

Offline s ǝoɾ

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Re: 94 5.9 No Start.....PCM Diagnosis?
« Reply #11 on: May 8, 2010, 08:36:16 AM »
Ok, found it.

Step 1: Connect DRB
Step 2: Follow on-screen directions for sensor test.

 ::) Seriously.

Else where I find something "slightly" more conclusive, but still shows how new dodge was to electronic systems at this time. (they didn't know that they didn't know)

The directions involve a illustration, but you will just have to picture this in your mind. Grab the pigtail from either sensor (CKP or CMP) unplug, and look at the 3 terminals. Orient the sensor pigtail connector so the locking tab is upwards. The center terminal is "B" the one on the right is "C". Set multimeter to ohms, atleast 10,000. Test resistance between pins. If it does not say "OL" it is bad. (This is with sensor removed from vehicle, "bench test")

Why is that not conclusive? Just like so many other diagnostic tests out there, it is easy to spot a "FAIL", but not so easy to stamp "PASS". Just because it passed that particular test doesn't guarantee it is "good". FAILING does guarantee it is "bad". (you can pass a test and still be stupid LOL)

A=8v reference
B=Ground
C=Signal.

C would be back probed (in circuit) to use the preferred multimeter or logic probe pulse test. Ground the black test lead where you see fit.
Avoid replacing any part that you have not proven to be faulty through extensive testing.

Offline s ǝoɾ

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Re: 94 5.9 No Start.....PCM Diagnosis?
« Reply #12 on: May 8, 2010, 08:42:52 AM »
the haynes manual describes a test with the multi meter watching the voltage rise and fall on the CMP sensor, which i did and it does.

However, there is no test outlined for testing the CKP sensor. I tried watching for signal with the meter, but i am not seeing any voltage fluctuation as i crank the motor around.

The ckp sensor does have voltage on its reference wire however.

No logic tester here...Sounds handy for situation like this.

Lastly, since my FSM is for an 89, it does not cover the CKP sensor at all.

Oh yeah, tone ring has 8 windows, it is not a 36-1 ring like you would see on a ford edis.

it uses the 8 windows, and the cmp sensor in series to tell it when #1 is on compression

I'm mixing up engines or something, and think I accidentally read the v10 crap when speaking of the tone ring. What ever, disregard.

I'm showing same tests for crank, cam, and vss. Makes sense, they are all hall effect and work like every other digital position sensor out there. on-off-on-off.

Yes, logic probe is a good investment for $25ish. Like a testlight but actually useful (and computer safe) poke a fuel injector, coil, cmp, ckp, vss, digital MAF/MAP, and watch the blinking LED, and observe polarity. Similar principle to a noid light but better. Think it is best off with square waves, never tried a analog DC, or a ac pattern against a logic probe.

"OL" is literally all the FSM indicates as far as testing. That's it.
Avoid replacing any part that you have not proven to be faulty through extensive testing.

Offline kawgomoo

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Re: 94 5.9 No Start.....PCM Diagnosis?
« Reply #13 on: May 8, 2010, 09:15:31 AM »
aahh gotcha.... logic testers are the dummy lights we used in the stereo shops. you could probe a wire and it would tell you polarity, all the while not popping air bags ;)  never really put two and two together....but i definitely have friends with those testers.

yeah the v10 uses a 36-1 ring and sensor in the side of the block...like it should be. This ring on the flywheel is total bullshit. I have seen a myriad of wiped out sensors in the past few days of research from the flexplate hitting them, the converter rubbing against them...ugh. what a piece of shit.

now i see why domestic guys use megasquirt. even the cheapest EMS is far better than the stock junk computer on this thing.

I would like to restate...NO VSS INSTALLED!!?!?!  is this a problem? :)

i will go test pins b c now, will tell ya what i get.


Offline s ǝoɾ

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Re: 94 5.9 No Start.....PCM Diagnosis?
« Reply #14 on: May 8, 2010, 09:29:43 AM »
FSM doesn't go into enough detail on the engineering level to be able to determine that. (vss relevance) Now, keep in mind, engines will start in park with the vss not getting any signal, so that may be a clue. ;)

No the CKP should not be inside a hot oily crankcase, The v10 had such a bad problem with that, that they were replacing entire crankshaft assemblies in the early days. Keep it outside. On my 94 it is on the front balancer. ;D 2 simple notches in the balancer itself, not a tone ring attached to it.

You had such a hatred for the MS in the beginning. I had no idea why. Is a very versatile system, and very much less expensive/more flexible than many other systems. What are your other options? AEM? DFI7? The only drawback people can find on the MS is "no SFI"....not that, that is a genuine draw back. Look on the bright side.....with batch fire you can run on just the dizzy CMP and not even have any crank sensor. You have full engine control/datalogging just like any other EMS, you can run most any sensor like other EMS, ect ect.
Avoid replacing any part that you have not proven to be faulty through extensive testing.

Offline kawgomoo

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Re: 94 5.9 No Start.....PCM Diagnosis?
« Reply #15 on: May 8, 2010, 11:47:31 AM »
FOUND IT! lol...we have fire!

holy shit man, i think i need to change my drawers.

Went back through and checked all the wires to the sensors. Well, i realized when i had been testing for power, i was grounding the black probe on the engine. Then it struck me, you are only testing half the circuit moron!!

Everywhere i have turned has said grounds, grounds, grounds. So i tested the orange wire and blk/blu wire...sure enough dead. But i knew or had power...so there it was. I traced the black/blu wire and it spiders off all over the place. I was sure it was grounded SOMEWHERE, but why the ground wasnt making it back to the ckp sensor, ill never know.

The harness that goes along the driver side valve cover, down to the tranny had been cut off. When i started looking there where Three blk/blu wires in there. This has got to be it i thought... so i stripped them back, grounded to the back of the head where the other main ground gang is at.



Tapped the solenoid wire, and she fired right up! Scared the living crap out of me. Fuel pump was not hooked up, i was just looking for spark, not expecting the motor to catch on the first hint of a revolution. lol.

So here we are....ready to put some exhaust on it, and start getting some data on the motor before i tear it apart :)

Offline s ǝoɾ

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Re: 94 5.9 No Start.....PCM Diagnosis?
« Reply #16 on: May 8, 2010, 12:00:25 PM »
Oops I forgot.  ;D
Voltage reading of over .200 volts (with everything plugged in and powered up) between middle wire and engine block=wire failure.

That wasn't in any book and slipped my mind.
Avoid replacing any part that you have not proven to be faulty through extensive testing.

Offline kawgomoo

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Re: 94 5.9 No Start.....PCM Diagnosis?
« Reply #17 on: May 8, 2010, 12:05:04 PM »
Oh yeah...for the record.

CKP Pin B&C, Self ranging fluke reads 1.5m ohms between the two pins NOT o.l. of course, this is a meter designed for coax so i dont know what limit it has..

ckp works fine....when ya ground it! lol.

doh!

Offline s ǝoɾ

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Re: 94 5.9 No Start.....PCM Diagnosis?
« Reply #18 on: May 8, 2010, 12:18:04 PM »
Oh yeah...for the record.

CKP Pin B&C, Self ranging fluke reads 1.5m ohms between the two pins NOT o.l. of course, this is a meter designed for coax so i dont know what limit it has..

ckp works fine....when ya ground it! lol.

doh!

That's fine, I'm sure that is definitely OL on a 10k or more common 20k range.  ;D

High end meters tend to have a 10-50Megaohm range. Suffice it to say, 1,500,000 ohms is "good enough" for most anything on an automobile, although high impedance capability ensures it has minimal draw on delicate circuits...a definite good thing.

So it's official? We can call this (FIXED!!!)?
« Last Edit: May 8, 2010, 12:20:16 PM by s ǝoɾ »
Avoid replacing any part that you have not proven to be faulty through extensive testing.

Offline kawgomoo

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Re: 94 5.9 No Start.....PCM Diagnosis?(FIXED!!!)
« Reply #19 on: May 8, 2010, 08:03:35 PM »
Yup..this puppy is fixed.

No clue on the meter, it was a freebie from a customer. I guess he felt pity on my test light made from a reverse light and some welding wire.. ;) It sure works nice though.....




Offline kawgomoo

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Re: 94 5.9 No Start.....PCM Diagnosis?(FIXED!!!)
« Reply #20 on: May 9, 2010, 04:30:56 PM »
5.9 Magnum Startup DiY Run Stand