M1078A1 crank but not starting - batteries?

[gemini25]

Hallo,

I own a M1078A1 (2003) and yesterday the truck broke down.
I drove for about 10km (sorry I am from Germany, so km and not miles ), turned the truck off and after 10 minutes I wanted to start it again. The starter cranked, but the engine doesn't come on.
Today I had a closer look and recognised, that two of the four batteries are quite dead (the two on the right side just have a voltage about 8V).
The strange thing is, the starter cranks, but nothing else happens.
I also tried to read the error code from the ECM (I have a diagnostic computer), but my computer couldn't connect to the ECM.
And the next strange thing is, if I press the "Lamp test" button on the dash board, just the bottom lights come on.
Can this all happens, because of the dead batteries?

And another question. Is this correct, that the 12V just be used for the lights and everything else is on 24V.

Thankx for you ideas. It's a great forum here.
Best regards
Theo

 

[Suprman]

Some of these trucks, engine ecm power goes thru a filter box. Has a mil plug in and out. If you look at the engine computer look right its around there. See if you have 24v in and out. I believe the inlet heater is on the same circuit. If you have fixed your battery issue and you cant comm with the engine ecm, chances are its dead from no power or issue with the ecm itself.

 

[gemini25]

Thank you, I will try it today.

 

[gemini25]

So, today I change the two dead batteries.
The good thing is, the "Lamp test" button illuminates all dash board lights again.
But the engine still doesn't run and I still don't have access to the ECM.

I have another question. On the attached picture I guess I see the fuel solenoid (If I'm wrong, please correct me).
If I unplugg the connector from the solenoid and I turn on the ignition (not pressing the red button), should I measure there a voltage (I guessed 24V DV)? Because there is no voltage.

If anybody has any suggestions, you are welcome.

Thank you.

 

[gemini25]

Oh, one more question.
Behind the dashboard, I found two plugs (P912 and J913), this plugs aren't connected, or?

 

[snowtrac nome]

Hallo,

I own a M1078A1 (2003) and yesterday the truck broke down.
I drove for about 10km (sorry I am from Germany, so km and not miles ), turned the truck off and after 10 minutes I wanted to start it again. The starter cranked, but the engine doesn't come on.
Today I had a closer look and recognised, that two of the four batteries are quite dead (the two on the right side just have a voltage about 8V).
The strange thing is, the starter cranks, but nothing else happens.
I also tried to read the error code from the ECM (I have a diagnostic computer), but my computer couldn't connect to the ECM.
And the next strange thing is, if I press the "Lamp test" button on the dash board, just the bottom lights come on.
Can this all happens, because of the dead batteries?

And another question. Is this correct, that the 12V just be used for the lights and everything else is on 24V.

Thankx for you ideas. It's a great forum here.
Best regards
Theo

check your circut breakers it sounds like the ecm is not getting power

 

[gemini25]

The circut breakers I allready checked. They all worked. I also checked the power in the harness plug of the ECM. I get there the 24v DV.

 

[chucky]

Im not sure but on an AO if the fuel solenoid doesnt see atleast 22 or 23 volts it wont open and release fuel to go to the cylinder you might make up a jumper wire from 24 volt battery post to the fuel solenoid and see if it starts

 

[Ronmar]

Well if it is getting power to the ECM... The ECM’s have an internal memory battery which has a finite lifespan. They fail and wipe The ECM programming... They are also not replaceable so you may need a new ECM... you may be able to pull the ECM and take/send it to cat to evaluate it...

 

[Ronmar]

Im not sure but on an AO if the fuel solenoid doesnt see atleast 22 or 23 volts it wont open and release fuel to go to the cylinder you might make up a jumper wire from 24 volt battery post to the fuel solenoid and see if it starts

A1’s dont have a fuel solenoid, they are electronically controlled fuel injection...

 

[fuzzytoaster]

It sounds like you have multiple issues going on with the most serious being unable to connect to the ECM. I have a thread on this "crank, no start" issue and it was the ECM that failed internally due to faulty battery and wiped its memory. If your computer can't talk to the ECM do the following:

1) double check all parameters on your computer and adapter to make sure they're compatible. What adapter are you using? What software?
2) ECM doesn't have power
3) Connection issue (wire harness)
4) ECM is dead

To simplify the situation you can obtain a 70 pin patch cable and plug directly into the ECM. If it still wont talk to you then it's dead. If it talks to you then you know you have a problem in the harness (power or connection)


The "Lamp Test" button only gives power to the dash lights to make sure they're not burned out. If the issue comes and goes it's a bad connection somewhere.

 

[gemini25]

@Ronmar
If it isn't a fuel solenoid, what is it else? I thought it's for shutdown the engine. So I should be under power, if you want to start the engine.

@fuzzytoaster
I use a Cat Com 3 Adapter (317-7485) fron China and ET 2015A.

On Monday I get an Cat technician and he try to read out the ECM. Cross the finger, that is's just a small problem.

 

[fuzzytoaster]

@fuzzytoaster
I use a Cat Com 3 Adapter (317-7485) fron China and ET 2015A.

On Monday I get an Cat technician and he try to read out the ECM. Cross the finger, that is's just a small problem.

I've had 2 of those units (clones) and running ET 2019A and they never could connect. I had a DPA3 adapter from the military that worked and a DPA4+ that also worked with the software.

 

[Ronmar]

@Ronmar
If it isn't a fuel solenoid, what is it else? I thought it's for shutdown the engine. So I should be under power, if you want to start the engine.

that is probably a HEUI High pressure oil regulator valve Or pressure sender. It is a solenoid that controlls the high pressure Engine oil used to power the injectors hydraulically.
HEUI 101:
Engine oil is pumped at high pressure between about 500 and 3000 PSI To a gallery that feeds all the injectors. There is a sensor and a solenoid needle valve on this oil gallery. The ECM monitors this pressure and controlls that solenoid to regulate the presure it desires To reach the injectors. The injectors use this oil pressure to fire hydraulically. Each injector has an electric Solenoid spool valve That is controlled by the ECM to send this high pressure engine oil against a piston. The piston in turn pushes a ram Piston that pushes diesel fuel into the spray nozzle. that rampiston is a fraction the size of the oil piston, 7:1 comes to mind So it multiplies the engine oil pressure mechanically. That 500-3000PSI engine oil yields 3500-21,000 PSI diesel injection pressure. This allows the ECM to control injection pressure, volume/duration and timing electronically just like any other EFI engine. No cutoff solenoid necessary as to stop fuel flow you simply stop firing the injectors...

 

[gemini25]

So, I know more. The EMC is dead.
Nows anybody a used one for my truck?

 

[coachgeo]

So, I know more. The EMC is dead.
Nows anybody a used one for my truck?

last resort if you can't find anything else. these might be china clones of ecm which is why I say last resort. But then again maybe made in Mexico?? sorry he did not leave a link in the facebook post..... so here is the post with his number.

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[Ronmar]

Being in germany, you might have trouble getting a used one and might be better off with a european cat rep. They can take your engine s/n and should be able to get the proper software in a new one to match the spec the engine was sold with...

 

[fuzzytoaster]

Make sure it's the exact same model stamped on your ECM. If it differs by even a few numbers it could cause a ton of head aches from constant check engine lights, derates, etc etc..

 

[JD4044M]

This makes me wonder why there isn't a Emergency Run Switch/Mode? Even my Generator in Nam had one to keep the lights on while under fire. Seem a low air or other minor problem could cause you not to move the truck out of danger?

 

[Ronmar]

This makes me wonder why there isn't a Emergency Run Switch/Mode? Even my Generator in Nam had one to keep the lights on while under fire. Seem a low air or other minor problem could cause you not to move the truck out of danger?

Well these are the joys of electronic fuel injection... although the way cat went about it seems a little bit prone to failure(or planned obsolescence). Have run Toyota EFI vehicles and tweaked and modded a lot of them Since the mid 80’s and I have never seen a bad toyota ECM...