Log in or Sign up

DD15 crazy sensor bank problem

Discussion in 'Heavy Duty Diesel Truck Mechanics Forum' started by PermanentTourist, Apr 21, 2018.

Page 2 of 3

Koren Bobtail Member

Joined:

Dec 29, 2018

Messages:

18

Thanks Received:

1

0

How many miles did you have on your truck??

Koren, Mar 4, 2019

#11
PermanentTourist Heavy Load Member

Joined:

Nov 9, 2016

Messages:

749

Thanks Received:

881

Location:

48 states + Canada

0

Koren said: ↑

How many miles did you have on your truck??
Click to expand...

Like 600,000 or so...

PermanentTourist, Mar 4, 2019

#12
Davud_de Bobtail Member

Joined:

Jan 13, 2019

Messages:

4

Thanks Received:

0

0

PermanentTourist said: ↑

2014 Cascadia with DD15

I am having one hell of an electrical problem with my sensors. Check engine light comes on and off, sometimes the engine stop light comes on and forces me to shut down because of "engine timing failure".

First off, here's my wonderful collection of SPNs:

SPN 5927 FMI 2 coolant sensors (this one is the most common, keeps coming on and off even when everything is running normal. The coolant temp gauge keeps displaying correct temperature. This one also started first, a few days ago, before all the other ones joined in yesterday.)

SPN 3510 FMI 4 ECM 5V sensor supply bank 2 circuit failed low

SPN 100 FMI 4 oil pressure sensor (when this one goes as I'm going down the road, the oil pressure gauge drops to zero and I know the real fun is about to begin soon)

SPN 723 FMI 8 camshaft position sensor time out
SPN 723 FMI 11 camshaft position sensor failure (when these last two come to play, that's when the shut down is forced. But if I keep pushing the override button, it keeps running with no noticeable charge in performance.)

SPN 3226 FMI 20 NOX sensor in emissions (might be unrelated)

These errors are frequentish but inermittent. Sometimes I can drive for hours with just the coolant sensor check engine light blinking on and off. Sometimes all of them will happen simultaneously, but when I turn the truck on a few hours later everything is clear. Sometimes it's the other way around - I park the truck healthy, but when I start it all the boys are back - and I have to try starting a few times before it will even drop the camshaft error and let me run, and then the errors drop off one by one in a few miles. So basically, it does not seem directly related to engine being hot or cold.

We are under a cross country load, so we are trying to make it to LA. Tried to take it to a shop in Canton OH, but of course just then the problem wasn't happening and we couldn't replicate it. The shop looked at my wiring harness and in their own words "couldn't find anything obviously evil".

So... any idea how to diagnose this? Any common trouble spots in the harness, etc, that could cause this combination? Also, can one bad/shorted sensor confuse the circuit into this chain reaction? Like, maybe the coolant sensor? Or are they pretty isolated?

Any advice appreciated. It's hard to go to shops with this when it doesn't happen on demand.
Click to expand...

Did you figure out what the problem was with the code spn 723 fmi8 I got the same thing for the 5th time and I’m looking for new ideas of what could it be
Thanks

Davud_de, Mar 13, 2019

#13
Koren Bobtail Member

Joined:

Dec 29, 2018

Messages:

18

Thanks Received:

1

0

His problem was the engine harness, so as mine, I believe. Please read 4 posts before

Koren, Mar 13, 2019

#14
PermanentTourist Heavy Load Member

Joined:

Nov 9, 2016

Messages:

749

Thanks Received:

881

Location:

48 states + Canada

0

Davud_de said: ↑

Did you figure out what the problem was with the code spn 723 fmi8 I got the same thing for the 5th time and I’m looking for new ideas of what could it be
Thanks
Click to expand...

Yes, replacing the oil-damaged engine harness cleared all those miscellaneous codes. The wire to that sensor must have been one of the damaged wires.

PermanentTourist, Mar 13, 2019

#15

Davud_de Thanks this.
Mannie602 Bobtail Member

Joined:

Aug 4, 2016

Messages:

2

Thanks Received:

1

0

i had the symptoms on my dd15 as far as codes. I replaced the harness and the codes went away and ran for a week. Now the codes all came back. There's no way i have zero oil pressure. I put a manual home made gauge where the oil pressure sensor goes and i have pressure. I've replaced the oil pressure sensor with harness also. Out of the codes i feel its the SPN 3510 FMI 4 ECM 5V sensor supply bank 2 circuit failed low
that's causeing it. Any experience with this?

Mannie602, Jul 5, 2019

#17

JMon Thanks this.
Erod787908 Bobtail Member

Joined:

Jul 21, 2020

Messages:

1

Thanks Received:

0

0

Mannie602 said: ↑

i had the symptoms on my dd15 as far as codes. I replaced the harness and the codes went away and ran for a week. Now the codes all came back. There's no way i have zero oil pressure. I put a manual home made gauge where the oil pressure sensor goes and i have pressure. I've replaced the oil pressure sensor with harness also. Out of the codes i feel its the SPN 3510 FMI 4 ECM 5V sensor supply bank 2 circuit failed low
that's causeing it. Any experience with this?
Click to expand...

Mannie602 said: ↑

i had the symptoms on my dd15 as far as codes. I replaced the harness and the codes went away and ran for a week. Now the codes all came back. There's no way i have zero oil pressure. I put a manual home made gauge where the oil pressure sensor goes and i have pressure. I've replaced the oil pressure sensor with harness also. Out of the codes i feel its the SPN 3510 FMI 4 ECM 5V sensor supply bank 2 circuit failed low
that's causeing it. Any experience with this?
Click to expand...

Hey did u ever find the problem to this. Currently have same problems. Sometimes i lose pedal

Erod787908, Jul 21, 2020

#18
Hadi Bakir Bobtail Member

Joined:

Sep 1, 2010

Messages:

38

Thanks Received:

14

0

Erod787908 said: ↑

Hey did u ever find the problem to this. Currently have same problems. Sometimes i lose pedal
Click to expand...

Try disconnecting the water pump harness connector at your water pump sensor, see if the engine light goes out and your oil pressure gauge starts working normal. They share the same 5v bank to MCM.

Hadi Bakir, Jul 29, 2020

#18
twleman Bobtail Member

Joined:

May 4, 2019

Messages:

1

Thanks Received:

0

0

Hadi Bakir said: ↑

Try disconnecting the water pump harness connector at your water pump sensor, see if the engine light goes out and your oil pressure gauge starts working normal. They share the same 5v bank to MCM.
Click to expand...

Can you elaborate on this 5v bank? Common circuit back to the MCM?

twleman, Mar 9, 2023

#20
SWM_TECH Light Load Member

Joined:

Apr 15, 2018

Messages:

139

Thanks Received:

145

0

Newer trucks that have a variable speed water pump have 5 volts going to it. Sometimes these fail and mess up the 5 volt. Other sensors share the 5 volt.
Looking at this diagram https://www.thetruckersreport.com/t...dule-mcm2-1-engine-harness-page-1-png.316183/. It appears engine oil pressure, camshaft position sensor and fuel compensation pressure sensor may all share the same 5 volt reference.

SWM_TECH, Mar 9, 2023

#20

(You must log in or sign up to reply here.)

Page 2 of 3

Search