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FIX-IT, Technician
Category: Heavy Equipment
Satisfied Customers: 1178
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Hello, I have a 2005 Sterling Acterra with an MBE900 engine.

Customer Question

I have a 2005 Sterling Acterra with an MBE900 engine. Just got back from a trip from texas and shut the truck down normally. Went to startup a week later and the batteries finally gave out( original Freightliner ). Repaced batts and engine would crank but not start. Acts as if no air or fuel. Checked air filter and replaced racor full filter( add-on)and pumped up fuel lines, but no change. Did get check engine after a couple of cranks. Any suggestions would be appreciated as I've only worked on diesel gen-sets w/manuals.

Submitted: 6 years ago.
Category: Heavy Equipment
Expert:  FIX-IT replied 6 years ago.
Hi there.i can help you with this..can you get the codes that were flashing on the dash? also when replacing batteries make sure all connections were put back on and fuses at batteries are ok to...sometimes its possible that when batteries are replaced a wire may fall down in behind batteries..and may be forgotten when batteries are hooked back up.let me know..
Customer: replied 6 years ago.
I'm down here in the Keys so don't have direct access to a dealer/repair shop. I replaced all connections exactly as removed..this is critical on gen-sets as they may control switchgear so I tend to be careful when doing this. Batteries where replaced with equivalent NAPA rating 910 CCA commercial batteries. I checked both fuse panels on the truck and found nothing blown. This was my third round trip to Texas in a year and only had to have the HVAC relay replaced. Everthing else had been working perfectly until I changed the batteries. Are there fusable links on the battery cables? I will check them for continuity. It's diffilcult to tell if starter is spinning fast enough.
Expert:  FIX-IT replied 6 years ago.
now you said you check the fuses,on most acterra'a there are 2 fuse panels,one under the hood and 1 behind the glove box,have you check there perhaps? and when the check engine light comes on,look at the message center on your dash,if it shows a number like 128 then hold the mode bottom down and tell me the other numbers that comes with it..
Customer: replied 6 years ago.

All I 've seen so far is just the check engine light. I will check to see if the mode button is active on my truck ( it's pretty basic vehicle) tonight after work. The description in the manual was not very clear.

I did check both fuse panels first thing thinking I might have popped something installing the new batteries...all looked good.

Expert:  FIX-IT replied 6 years ago.

k.. it looks like we'll have to do some voltage checks..let me know if u get a code..

Customer: replied 6 years ago.
I turned the ignition on and did not get a 'check engine'. I cranked the engine two times on short bursts and did not get the check engine light( this was after disconnecting the batteries to check all three had good voltage and were charged up)( possibly overcranking brought in a check engine for low voltage?) I do not have the mode button on my dash so it would not have helped anyway. A very basic truck.
Expert:  FIX-IT replied 6 years ago.
Alright,ill need the vin # XXXXX your truck and engine serial #
Customer: replied 6 years ago.








Expert:  FIX-IT replied 6 years ago.
Ill look it up and get back to you..
Customer: replied 6 years ago.
Relist: I still need help.
My MBE900 still will not start. I cracked a couple of injector lines and cranked the engine to verify if I had fuel up to that point. I swapped a couple of "engine run " relays around that were idendical. rechecked fuses and ground connections OK. I still think it might be electrical as the only thing I did was change batteries. Is there a set of relays that would cause this?
Expert:  FIX-IT replied 6 years ago.

sorry for the delay in getting back,next we'll have to do some pin out checks

first the vcu its located somewhere under your top dash panel or bottom of dash panel you will find a rectangular box with either 4 or 3 plugs to it at the 21 pin connector at pins 1 battery 2 ignition 3 gnd verify that first,at the wire insertion side you will see the numbers....very small but they are there next at the pld at your engine,the small plug check 5 and 6 battery 9 and 11 gnd 15 is switched,,check that and get back to me with the results...thanks..this will help



Edited by FIX-IT on 6/16/2010 at 2:15 AM EST
Customer: replied 6 years ago.

I found the VCU and checked #1 pin @ 12.6 volts, # XXXXX pin @ 12.47 volts w/ ignition on.

The engine plug was a little more difficult. I have 7 contacts and no visable numbers.

Plug attached to engine, toward cab, third contact from top had 12.62 volts, fourth contact had 12.62 volts, seventh contact had 3.52 volts w/ ignition on, eight contact had 5.32 volts w/ ignition on. Plug attached to eng toward radiator, second contact had 12.45 volts, contacts 6 & 8 had no voltage in either position. I had to ground to frame for readings not knowing what contact was ground or the numbering system for this plug.

A friend suggested the camshaft TDC was not working, I tested by cranking and got tach movment.


Hope this helps.

Expert:  FIX-IT replied 6 years ago.
try this look at the pic for the 16 pin connector,i need you to verify the power gnds and switched,very important,sounds like vcu is good to go...
Customer: replied 6 years ago.

I checked voltage per your instructions and pinout diagram.

Black probe to #11 ground, red probe to # XXXXX contact read -12.63 volts.

Ignition on: black probe to #11 ground and red probe to #15 contact read -9.06 volts.



Expert:  FIX-IT replied 6 years ago.
pin 15 thats the bad boy,take the plastic shield off the plug take the wire back 6 inches cut and strip,jump 12 volts there and retest,should be ok.keep in touch.
Customer: replied 6 years ago.



I strippped the cable covering on the 18 pin connector, but did not understand opening the # XXXXX pin wire and applying 12 volts to the 6 inch section.

I did strip the wire back 2 feet opened the wire ( 439B?D?) as marked, turned the ignition on and got 9 volts. I then traced (439B?D?) to the VCU and with ignition on got 12.26 volts. I disconnected the bulkhead connector to try and localize the resistance problem, but did not get any voltage that made sense e.g. 8.35,8.35 and one at 7.90 volts. Still not shure where the problem is comming from.

Expert:  FIX-IT replied 6 years ago.

Just remember that circut 15 is ignition to the pld cut and strip the wire and applying 12 volts there and the retest will confirm thats the problem,put 12 volts to the wire going to the pld don't apply 12 volts to the wire going to the fire wall.just be sure that you are on the right circut per that diagram i sent..let me know..

Customer: replied 6 years ago.
I stripped the wire and hooked up a direct battery source at pin #15 and got 12.27 volts to frame ground. I then took a reading from direct battery on pin #15 to the pin #11(ground ) on the 18 pin connector, I got zero volts. Bad ground? and how to find it?
Expert:  FIX-IT replied 6 years ago.
well my friend the ground goes back to the batteries,sometimes ground stud usually close to batteries, if you can't find the rewire 11 and 9 to battery gnd and retest,let me know how you made out..
Customer: replied 6 years ago.

I did some more testing since I was getting voltage from pin #6 to pin #11, zero voltage from pin #15 positive side of battery to pin #11

. I reversed to negative side of battery with the jumper and got 12 volts from pin #15 and #11. Is igniton pin #15 positive or negative? ( engine cranked ok did not start).

Could the VCU be doing this? I'll keep playing with it. I'm starting to get fond memories of replacing water pumps and injectors on 3406's and fuel pumps on 12v92's.

Expert:  FIX-IT replied 6 years ago.

15,5 and 6 should all be power at key on,i need you to verify that,check with a head light if you have one,its a good test to check the integrity of the wire if not what are you readings with your meter,once again pin 15 is keyed power..

Customer: replied 6 years ago.

I went back to original wire connections. Igntion off: red probe to #6 black to #11 -12.72 volts,,red to #15 black to #11 -.112 volts.


Ignition on: red to #6, black to #11 -12.52 volts

red to #15 black to #11 -9.02 volts


My Fluke 77 iis the meter I'm using..

Expert:  FIX-IT replied 6 years ago.
i don't like that 9.0 volts at 15,the pld needs to see at least 11.0 volts to turn on,i know you stripped that wire from before,jump 15 to battery positive plug back in and retest,b 4 u said you had no gnd at 11 and 9 ,what happened there ?
Customer: replied 6 years ago.
When I had (+) jumped from battery to # XXXXX pin connector to #11 I got zero volts. When I reversed polarity with the jumper, I got 12 volts from pin #15 and pin #11. I tested to frame ground OK in all tests to ensure I had good wire. I did jump positive battery voltage direct to pin #15 and installed plug back on engine....cranked but did not start.
Expert:  FIX-IT replied 6 years ago.


ok if you jumped battery power to 15 thats good,next we need to load down the battery circuts the best thing is a headlight,one side to 5 other to 11 next 6 to 9 when you checked 5 to 11 you said you got -12.5 is that right ? negative? where you multimeter leads backwards?..let me know,its possible your leads are backwards or something isn't right at your batteries,let me know before you do anything..

Customer: replied 6 years ago.

When I installed the new batteries, I verified connections, having spent the last ten years running and maintaining diesel-generators at an air base it can be critical to prevent damage to switchgear and automatic controls. So yes, the battery negative cables (black) attached to frame and positive(red) atttached, verified with two different DMM's with the possibilty the batteries were mismarked (trying to double check everything)

My Fluke meter com(black) and V,A, ohms(red) This is why I made a point about the (-) reading I was getting.

This does not sound normal per the diagrams I have.(DDEC wire listing and pinout for 16 pin engine plug.)

I'm looking for somethimg to use as a 12 volt load source. I never had a spare headlight laying around even with the three 20-30 year old cars I own( I maintain my own)

This is why I like the old vehicles, simple. If you need verification on anything, let me know.

Expert:  FIX-IT replied 6 years ago.
Any headlight will do,let me know..
Customer: replied 6 years ago.

I set up a 50w 12 volt test light, verified it at the batteries.

I connected it to pin # XXXXX and #11 and got good brightness.

I hooked it up to pin #15 and #11 and did not get a light...checked voltage under light load

light off -9 volts

light on -.002 volts


Expert:  FIX-IT replied 6 years ago.
that 15 is suspect,run battery power there and retest..thanks
Customer: replied 6 years ago.

I jumped from the red...positive side of the battery terminal to pin #15 pigtail.

Clipped the light to pin #15 and light.

Expert:  FIX-IT replied 6 years ago.
interesting 11 and 9 are gnd. cut and splice to battery gnd.and retest.let me know..
Customer: replied 6 years ago.
Wired black (-) from battery to pin #11 (ground) and red (+) to pin #15....light on.
Expert:  FIX-IT replied 6 years ago.

before plugging in with your light confirm all circuits are good...confirm polarity is right.reassemble and retest,,

Customer: replied 6 years ago.

Wired system back to normal and took the following readings from the 16 pin conn:


Ignition off using fluke DMM ---black to #11, red to # XXXXX volts

" " " " black to #11, red to #6.....-12.57 volts

" " " red to #11, black to #15.....12.50 volts

" " " red to #11, black to #6.....12.57 volts

Ignition on " black to #11, red to #15.....-8.9 volts

" " black to #11, red to #6.....-12.42 volts

" " red to #11, black to #15.....9.07 volts

" " red to #11, black to #6.....12.40 volts

Expert:  FIX-IT replied 6 years ago.
your readings are still off with key on you should have..

11 or 9 to 15 ...12 volts or better...can't say -12.0
5 or 6 to 11 or 9..12 volts or better
with your readings above with key on..
i need to make sure your looking at the plug correctly
blk 11 to red 15 should be 12.0 or better
blk 11 to red 6 should be 12.0 or better
blk 9 to red 5 should be 12.0 or better
no negative numbers....
Customer: replied 6 years ago.

I have the VIH to DDEC-ECU connector wiring print from June 17th answer that shows the picture of the connector.

It says at the bottom of the picture " looking into the Pins on the Harness"" Front"

Reading the picture.....On the Right, pins 1-8....On the Left, Pins 9-16, is this OK?


Is this correct? If so, those are the readings I'm getting. Is there a relay or something else that could reverse or dimminish the voltage on #15? I get -9 volts going from pin #15 diectly to frame ground as well.

Expert:  FIX-IT replied 6 years ago.
no there would nothing that cause reverse polarity you see the notches on the top and bottom of plug.thats there to help you id the pins let me know how you did..
Customer: replied 6 years ago.

According to the drawing on the print, by reading the shell markings, I've been reading everything upside down.

Took new readings....pins #5&6 (battery) to pin #11 reads 12.4 volts.


Pin # XXXXX and pin #11 ign volts....ign on read 12.48 volts.



Expert:  FIX-IT replied 6 years ago.

sorry for the confusion,im glad we got that pld and vcu are good yes?

when you key on the check engine light comes on?

if so when cranking does it come on or stay on ??

also reconfirm that cicuts pass headlight test..

Edited by FIX-IT on 7/6/2010 at 12:04 AM EST
Customer: replied 6 years ago.

I rewired everything back to normal setup.

I light tested both battery pins to #11 ground.....light OK.


I hooked light to pin #15 and #11, no light w/ ign off....good light w/ ign on.


Turn ignition on with original factory connectors plugged check engine light.


Cranked engine a good 10 secounds check engine light


pld and vcu good? I guess...voltage checks to vcu were good.

Expert:  FIX-IT replied 6 years ago.

have you done anything else to this vehicle besides batteries,lately and hey its good we got that wiring thing sorted out.sorry for taking as long as it did..

has there been any work done to transmission clutch flywheel ?

Customer: replied 6 years ago.

I'Ve had the truck since this time last year and the only problem I had was the hvac relay went bad. I had it replaced in Abilene and the front disk brake pads replaced. I was getting a coolant and transmission temperature indications that were funny and had both replaced at the same time. They have been working good on my last two trips.

I changed the oil once....that is all I've done to the truck.

Expert:  FIX-IT replied 6 years ago.


with the key on does the check engine light come on? does it stay on ?does it go out?

confirm foul level is good in both tanks

confirm no fuel leaks anywhere along driver side of engine

pull black covers off that say mercedes benz and confirm

let me know of all results


Customer: replied 6 years ago.

The check engine light does come on when I turn the key on...then goes off after the gauge test.


Fuel level is 60 percent...visable check OK.


Checked fuel lines by engine look good( did that when I replaced fuel filters).


I pulled the covers when I cracked a couple of the fuel lines to check fuel to injectors when cranking. No leaks seen at that time. No fuel in oil indicating loose injectors. No obstructions or debri in old fuel filters, no water found in racor prefilter when changed and refilled with fresh JP5( from D-G day tank at work.)


Expert:  FIX-IT replied 6 years ago.

ok next i want you to check the crank sensor,its ontop of trans and to the drivers side of engine,you may have to remove shifter boot or 1/4 fender to access,there are 2 back there cam and crank,,go after the one pointing towards the ring gear remove inspect and clean...reinstall and make sure it bottoms then go to your electronic unit pumps and in between 5 and 6 you'll see a fuel line that goes into a tall fitting...thats your fuel pressure regulator.remove and inspect let me know what you find..

Customer: replied 6 years ago.
OK. I finally got to a point that I have access to the sensors. How do I remove the connector without destorying it? Most of these have some pretty unique attachments.
Expert:  FIX-IT replied 6 years ago.
yes they are delicate,now gently with a flat head screw driver or small heel bar.pop the sensor out.make sure its the one pointing towards the flywheel...keep me in the loop..
Customer: replied 6 years ago.
OK... I pulled the sensor, it was backed out about an eight of an inch. I cleaned it and pushed it back in until was as far as it would go. I looked at the other sensor w/o pulling and it also was pushed in as far as it would go. I test cranked the engine about 20 secounds with no start and no check engine light when cranking. Do these sensors go bad? I can do the fuel regulator, but what should I look for ?
Expert:  FIX-IT replied 6 years ago.

that regulator is basically a check valve

has a ball and spring and what happens is the ball moves off to one side and doesn't seal proper and thus fuel will pass through it prematurely and thus low fuel pressure.have a look but man.its just so odd that this problem off yours came up after doing the batteries none the less lets have a look or perhaps we can check fuel pressure and this is done by removing fuel temp sender and plumbing in a guage.that sender is in front of all your electronic unit pumps front of number one actually.let me know how you did..

Customer: replied 6 years ago.

I checked the the fuel pressure regulator...ball is centered and passes the puff test.

Testing fuel pressure is going to be a little harder as all my high accuracy test gauges are allready in Texas, also I'm not shure I would get much pressure just cranking the engine. I did check flow by disconnecting 1&2 lines to the block and got a little flow when I was checking for blockage in the fuel lines.

Expert:  FIX-IT replied 6 years ago.
is there anyway you can get a pressure bleeder.? that would be the best.another way is if you have 2 fuel tanks shut one off and put 10 psi in the other and crank...thats actually the older way the factory uses to start the trucks after building
Customer: replied 6 years ago.



Sorry for the delay, it took awhile to do some more troubleshooting....The engine has no compression...looks like a dammaged head. Would not start on ether and has blowback out of the intake. Pulled the rocker shaft to veryfy. ( all valves shut)


Thanks for all the help.

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