LMM: P0047 but wiring checks out.

badmatt

AVOCADOMAX
Mar 21, 2015
21
42
13
Hey All,

Truck is a 07.5 LMM, Deleted, 150K, truck sees 3000RPM daily and is typically driven in tow haul for city driving.

Need some guidance or assistance. I have recently come into a P0047 code and i'm at a loss for words. Truck does not have any other codes. I have done the following;

- Checked the wiring from Terminal A to pin 48 and reads 4.5 Ohms.
- Terminal B to pin 96 and get a reading of 4.5/4.6 Ohms.
- Tested the pins to the engine for a short in either circuit in both directions I get - infinite resistance.
- Testing across the VGT solenoid I get 4.6 Ohms at roughly 30*C oil temp
- I get 8V across terminal A and B on the harness with key ignition on.
- Fuse 19 see's battery voltage across the fuse while running and with key on.

Vanes are currently in 0% position with a 9% request at idle. I have no way to command the vanes currently. Could the solenoid still potentially be hooped?

Thanks, Matt.
 
Last edited:

KyleC4

Tech
Dec 30, 2016
470
48
28
Bay Area
So testing terminal A to pin 48 is 4.5 ohms? This is what you got with ecm and solenoid unplugged ? Most pin to pin resistance tests should be less than 1 ohm. Your resistance measured across VGT solenoid itself is good. So that makes me think your meter is reading correctly.
 

badmatt

AVOCADOMAX
Mar 21, 2015
21
42
13
So testing terminal A to pin 48 is 4.5 ohms? This is what you got with ecm and solenoid unplugged ? Most pin to pin resistance tests should be less than 1 ohm. Your resistance measured across VGT solenoid itself is good. So that makes me think your meter is reading correctly.

Yes, verified with everything unplugged. Im starting to think the solenoid has failed.

Checked the solenoid at ambient temp (10°c) and for 8 ohms.. so maybe the solenoid is no good?

I also grab another multimeter and test the circuit again.
 
Last edited:

badmatt

AVOCADOMAX
Mar 21, 2015
21
42
13
Alright,

Figured it out. It is the solenoid!

I Found my Ole Fluke 73 and retested the ECU wires, 0.03 ohms both directions and no shorts to ground.

Purchased a Caterpillar 366-9748 which is a fuel injector pig tail, which is the same connector as the VGT solenoid just to give myself a fighting chance with confined spaces..

Resistance across the solenoid terminals at ambient (15*C) solenoid reads 3.48 ohms. I then tested from either pin to the body of the solenoid and it registered 3.4 Ohms from one pin to the body of the solenoid...

SO the solenoid is shorting to it self...

I Lit the shitty multimeter on fire... and ill have a new solenoid Monday....

Thanks everyone for reading and thank you to KyleC4 for making second guess my multimeter!