How JustAnswer Works:
  • Ask an Expert
    Experts are full of valuable knowledge and are ready to help with any question. Credentials confirmed by a Fortune 500 verification firm.
  • Get a Professional Answer
    Via email, text message, or notification as you wait on our site.
    Ask follow up questions if you need to.
  • 100% Satisfaction Guarantee
    Rate the answer you receive.
Ask sprinkles08 Your Own Question
sprinkles08, ASE Certified Technician
Category: Chevy
Satisfied Customers: 22827
Experience:  ASE Master and Advanced level certified. Factory trained with 15 years dealership experience
Type Your Chevy Question Here...
sprinkles08 is online now
A new question is answered every 9 seconds

Chevy boys I have a '05 truck 3500 6.6L Vin

Customer Question

hi chevy boys
I have a '05 truck 3500 6.6L Vin 1GCHK33285F869512
engine cranks but it does not stay on cuts off
I have this codes on memory
PCM codes P0201 all the way to P0208 all injectors
P1294 inject ckt low
airbag module codes
transmission module
passenger presence system
I need to know if is PCM is problem or fuel control module
thanks guys
Submitted: 1 year ago.
Category: Chevy
Expert:  Juan Crespo replied 1 year ago.

Hi there.

Codes P2146 and P2149 shouldn't set when U0105 is present, so, after reading all the other codes and symptoms, I'm going to say we have either a massive power failure or the fuel injection control module (FICM) has failed and taken the PCM along for the ride. Of course, we could confirm or debunk my theory this with the aid of a Tech-II loaded with the right software. Do you have access to one of those?

Customer: replied 1 year ago.
No but I found at PCM 2 pink wires without voltage blue connector pins 42 and 56
That has to be it verdad juan
Expert:  Juan Crespo replied 1 year ago.

Give me a couple of minutes to double check, but I think you got it! Be back in a bit...

Expert:  Juan Crespo replied 1 year ago.

Si, mi amigo. Both Pink wires going to 42 and 56 are supposed to have ignition voltage from the ECMRPV fuse (15A). That fuse gets power from the EDU relay.

Customer: replied 1 year ago.
Ok Juan tengo power al EDU relay both powers
No power at ECMPRV fuse
does el relay comes on con la ignition on
And does PCM activates relay by sending ground to it now power to fuse
Customer: replied 1 year ago.
I meant that fuse has no power
I need to know what activate relay
Customer: replied 1 year ago.
Ok Juan I found why I have no power
It was because connector is unplugged there is no relay action
So I'm back to square one again
Truck will start for a few seconds and cuts off
How about theft problem could it be there ?
Expert:  Juan Crespo replied 1 year ago.

Is the Security warning light coming on the dash?

Customer: replied 1 year ago.
then goes off
As it should
Expert:  Juan Crespo replied 1 year ago.

OK. So that means we don't have a problem with the Security system. Give me a few minutes to research this issue some more. Be back in a bit...

Customer: replied 1 year ago.
Gracias buddy
Expert:  Juan Crespo replied 1 year ago.

Without having the benefit of a scan tool to confirm my theory, I'm thinking a wiring problem is causing all these issues - could be a bad FICM, but those don't go belly-up very often.

Look at the injector harness and all of the connections involved, including the individual injector connectors as well as the big connector at the FICM - anything looks suspicious, disconnect the wiring at both ends, then take your Ohmmeter and make sure resistance is under 5 OHMs on that circuit.

Please let me know what you find.

By the way, working on these systems without a capable scan tool is like trying to build a car with just a screwdriver and some pliers; near impossible. Is there any chance of you borrowing a good scan tool? somewhere?playing Russian roulette

Customer: replied 1 year ago.
I got a snap on Verus up to 2014
What do I need to check with it ?
I'm about to scan all modules and clear coded
And then reprogram scan to see what comes up
Customer: replied 1 year ago.
After clear codes and try to start engine
And rescan this codes came back
See attachment
Customer: replied 1 year ago.
I will concentrate on 2146 and 2149
That's where I will do tell me something about this codes what can trigger them
Customer: replied 1 year ago.
Bud how can I test for voltage both communication line to see if FICM is talking to PCM
Expert:  Juan Crespo replied 1 year ago.

That's the thing. Testing voltage on the bus lines doesn't tell you whether or not the modules are communicating with one another or what they're doing with the data being transmitted - only a Tech-II or equivalent scan tool can do that.

Codes P2146 and P2149 set when there is no or low circuit voltage detected. In this case, probably because there is no power coming out of the EDU relay.

NOTE. I have to log off for a few hours. I'll be back later tonight to answer any other questions you may have.

Customer: replied 1 year ago.
ok amigo
I have checked all injectors circuit and activated all injectors with 12 volts all of them clicked fine
I have checked all powers and grounds of injectors module
the only thing I see is that FICM is not sending the 12 volts that it is supposed to send in orange and red/white wires
to power injectors and EDU relay and ECMRPV fuse come on so FICM doen't lack power
I think module is gone q piensas my fried
also I found injector 7 leaking when I disconnected it
but I don't think a leaking injector will cause no start engine misfire yes
thanks amigo be waiting
Expert:  Juan Crespo replied 1 year ago.

You are correct in thinking a single leaking injector won't cause the engine not to start. However, it may cause the pressure to decrease to the point of not being able to open any of the injectors.

If I had to guess, then I'd still say the wiring is bad and that's why the engine won't start. You see, testing injectors as you did doesn't really tell us the amperage it took to fire them - something that can only be done with a scope and a low-amp probe. All electrical loads such as injectors, motors, etc. use electrical power that is measure in Watts. Watts = Volts X Amps.

If you were a big shop with lots of used parts laying around, then I would tell you to try another FICM and see what happened, but you're probably don't have one to try.

I hate to state the obvious, but technical knowledge alone is not enough to diagnose and repair these systems; you need to have the right tools.

Customer: replied 1 year ago.
ok bud lets do it I got a scope
where do I start
Customer: replied 1 year ago.
I forgot I have a 4 channels lab's cope
Will this work to keep diagnosing ?
Expert:  Juan Crespo replied 1 year ago.

How about the low-amp probe? This is what I posted: "something that can only be done with a scope and a low-amp probe" - and this is just to test injector draw. We still don't have the scan tool to test the rest of the system.

Man, I do wish I could help you, but I can't do so without you having a capable scanner. I'm going to opt out and re-open your question to the field to see if another expert has something to contribute.

Best Regards.

Customer: replied 1 year ago.
thanks Juan appreciate your help anyway
Expert:  sprinkles08 replied 1 year ago.

Hello and welcome to JustAnswer!

Do you still need help?

Customer: replied 1 year ago.
I do I need to know how to check FICM
Expert:  sprinkles08 replied 1 year ago.

Can you clear the fault codes, crank the starter for ten seconds without letting off the key and then see what codes come back?

Customer: replied 1 year ago.
SHOP is close no so I will do that on Monday
And thanks for your help Sprinkles 08
Expert:  sprinkles08 replied 1 year ago.

You're welcome!