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P05ED Code - DEF Heater Line?

SOP

Member
Dec 11, 2017
48
11
Truck Year
2014
I've got a P05ED code that keeps popping back up after I clear it. Anybody have experience with this? From what I have found online it's related to the DEF Heater line... Perhaps this is something that might be covered under the extended settlement warranty??
 

GearHead

Active Member
Sep 13, 2016
380
133
Truck Year
2014
I've got a P05ED code that keeps popping back up after I clear it. Anybody have experience with this? From what I have found online it's related to the DEF Heater line... Perhaps this is something that might be covered under the extended settlement warranty??
Wow that is a new one, never have seen or heard of that one. Had to dig to find it. OK lets start that code is referred to as "Reductant Heater Control Module Supply Voltage" it means that the module is receiving too little or too much voltage. You will not be able to just clear the code and go on. You will need to trace down the wiring to that module and check for voltage. Recommend a Personal Use AllData subscription and a good digital voltage meter.
Good luck.
 

SOP

Member
Dec 11, 2017
48
11
Truck Year
2014
Wow that is a new one, never have seen or heard of that one. Had to dig to find it. OK lets start that code is referred to as "Reductant Heater Control Module Supply Voltage" it means that the module is receiving too little or too much voltage. You will not be able to just clear the code and go on. You will need to trace down the wiring to that module and check for voltage. Recommend a Personal Use AllData subscription and a good digital voltage meter.
Good luck.
GrearHead - thanks for the reply. I've been tied up with work the last several days and have yet to figure this out. I did reach out to GDE and they are always extremely helpful. They literally replied to me over the weekend of Thanksgiving and was not expecting a reply till early the following week. How much better customer service can you get than that!!!

Here's what they recommend. Figured I'd add this to my post incase someone else has this same issue:

In doing some more digging, this does not have much to do with the DEF line heater itself but the main power that goes to the DEF system heater control unit.

First you'll want to check F31 in the fuse box assembly that's underhood. It should be a 30A fuse. If it is blown and immediately blows again when you install a new fuse then somewhere the main power line is rubbed thru and shorted to ground.

If the fuse is fine, then you'll want to check for power at the DEF heater control unit. It is located on top of the crossmember that passes under the rear of the cab, the connector has a large orange/red handle that you pull out to disengage from the control unit.

The main power coming in related to this code is at pin 11 per the below:


1638392112827.png
If the fuse is good but there’s no power in the connector then you’ll have to work back thru the harness to find where the power is lost.

You might also check with the dealer, as this kind of stuff should be covered under the AEM warranty extension if yours is still active.
 

SeanPwnery

Member
Nov 30, 2022
91
33
Truck Year
2016
Apologies if this seems like a thread necro - but this code popped up for me last night out of the blue. I scanned it, it came up, I scratched my head and cleared it. It didn't come up at all today for both trips I made, but I suspect I'm still in closed-loop mode right now.

Here's the strange thing - last night was the coldest night so far this year (and it was only in the upper 40's so it's nothing extreme), and I had the heater cranked up to a million. Only when the inside of the truck became unbearably hot where I wanted to turn off the heater, that's when the CEL lit off and threw that code. Coincidence?
 

bent

New Member
Oct 27, 2020
11
2
Truck Year
2017
Apologies if this seems like a thread necro - but this code popped up for me last night out of the blue. I scanned it, it came up, I scratched my head and cleared it. It didn't come up at all today for both trips I made, but I suspect I'm still in closed-loop mode right now.

Here's the strange thing - last night was the coldest night so far this year (and it was only in the upper 40's so it's nothing extreme), and I had the heater cranked up to a million. Only when the inside of the truck became unbearably hot where I wanted to turn off the heater, that's when the CEL lit off and threw that code. Coincidence?
Sean,
I just repaired this fault on my 17 ecodiesel, here's what I found.
The trouble shooting SOP mentioned above is spot on.
Check fuse 31 for continunity
if good check pin 11 on the plug for the heater control module, found on the cross member above the drive shaft near the transfer case.
This is a hot at all times circuit so no key on needed. Circuit A914
if no power there
check for power on pin 14 of the middle large connector on the outside of the drivers side frame rail
If you have power there
then there is a splice above the DEF tank (SP1899) that likely has failed and the tank will need to be dropped
open the tape and the failed wire becomes easy to spot.
That's where mine failed.
Wayne
 

arod450

New Member
Sep 21, 2023
2
0
Truck Year
2015
Sean,
I just repaired this fault on my 17 ecodiesel, here's what I found.
The trouble shooting SOP mentioned above is spot on.
Check fuse 31 for continunity
if good check pin 11 on the plug for the heater control module, found on the cross member above the drive shaft near the transfer case.
This is a hot at all times circuit so no key on needed. Circuit A914
if no power there
check for power on pin 14 of the middle large connector on the outside of the drivers side frame rail
If you have power there
then there is a splice above the DEF tank (SP1899) that likely has failed and the tank will need to be dropped
open the tape and the failed wire becomes easy to spot.
That's where mine
 

arod450

New Member
Sep 21, 2023
2
0
Truck Year
2015
This is happening to me right now, but my heater in the cab blows cold too, are both things related?
 

bent

New Member
Oct 27, 2020
11
2
Truck Year
2017
This is happening to me right now, but my heater in the cab blows cold too, are both things related?
No , the cab heater blowing cold air has nothing to do with heating the DEF tank and lines.
Wayne
edit: spelling
 

Rockstar

New Member
Jan 18, 2024
3
0
Truck Year
2018
GrearHead - thanks for the reply. I've been tied up with work the last several days and have yet to figure this out. I did reach out to GDE and they are always extremely helpful. They literally replied to me over the weekend of Thanksgiving and was not expecting a reply till early the following week. How much better customer service can you get than that!!!

Here's what they recommend. Figured I'd add this to my post incase someone else has this same issue:

In doing some more digging, this does not have much to do with the DEF line heater itself but the main power that goes to the DEF system heater control unit.

First you'll want to check F31 in the fuse box assembly that's underhood. It should be a 30A fuse. If it is blown and immediately blows again when you install a new fuse then somewhere the main power line is rubbed thru and shorted to ground.

If the fuse is fine, then you'll want to check for power at the DEF heater control unit. It is located on top of the crossmember that passes under the rear of the cab, the connector has a large orange/red handle that you pull out to disengage from the control unit.

The main power coming in related to this code is at pin 11 per the below:


View attachment 3586
If the fuse is good but there’s no power in the connector then you’ll have to work back thru the harness to find where the power is lost.

You might also check with the dealer, as this kind of stuff should be covered under the AEM warranty extension if yours is still active.
I’ve went through all wires and still have power at pin 11 at the control unit. Would this then be my control module is bad?
 

Rockstar

New Member
Jan 18, 2024
3
0
Truck Year
2018
If you have power on pin 11 I would strongly suspect the control module. Could also be the CAN buss control wiring but the module would be my first guess.

Wayne
Thank you for the response… I put the new module in and the code did not clear, I’m out of ideas. I can’t find anything on the web about this code. Any last ditch ideas? Thanks
 

Mar

New Member
Dec 1, 2019
8
1
Truck Year
2016
Wow that is a new one, never have seen or heard of that one. Had to dig to find it. OK lets start that code is referred to as "Reductant Heater Control Module Supply Voltage" it means that the module is receiving too little or too much voltage. You will not be able to just clear the code and go on. You will need to trace down the wiring to that module and check for voltage. Recommend a Personal Use AllData subscription and a good digital voltage meter.
Good luck.
I would check the DEF injector on the catalytic converter. One allen key to remove. Found my def injector totally plugged with calcium. Use tap water to clean and blow gun. Code delete code and go fir a drive.
 

bent

New Member
Oct 27, 2020
11
2
Truck Year
2017

Thank you for the response… I put the new module in and the code did not clear, I’m out of ideas. I can’t find anything on the web about this code. Any last ditch ideas? Thanks
Did you measure the voltage on pin 11 with a mulitmeter as the fault can indicate a high or low voltage? What was the reading? Was reading taken right at the connector? Will the engine start and run as there is also a switched power to the "auto stop relay"? The only other connections this fault code should reference is the CAN bus itself. Hopefully I'm late with my reply and you have already figured this out. If so what was the fix?
Wayne
 

Josedm74

New Member
Oct 1, 2024
3
0
Truck Year
2014
GrearHead - thanks for the reply. I've been tied up with work the last several days and have yet to figure this out. I did reach out to GDE and they are always extremely helpful. They literally replied to me over the weekend of Thanksgiving and was not expecting a reply till early the following week. How much better customer service can you get than that!!!

Here's what they recommend. Figured I'd add this to my post incase someone else has this same issue:

In doing some more digging, this does not have much to do with the DEF line heater itself but the main power that goes to the DEF system heater control unit.

First you'll want to check F31 in the fuse box assembly that's underhood. It should be a 30A fuse. If it is blown and immediately blows again when you install a new fuse then somewhere the main power line is rubbed thru and shorted to ground.

If the fuse is fine, then you'll want to check for power at the DEF heater control unit. It is located on top of the crossmember that passes under the rear of the cab, the connector has a large orange/red handle that you pull out to disengage from the control unit.

The main power coming in related to this code is at pin 11 per the below:


View attachment 3586
If the fuse is good but there’s no power in the connector then you’ll have to work back thru the harness to find where the power is lost.

You might also check with the dealer, as this kind of stuff should be covered under the AEM warranty extension if yours is still active.
Ok when I check voltage on fuse f31 is measuring only 6v what it should measure 12v
 
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