Dead Pedal

[Ozymandias]

Body control module - that sits in front off the driver's side battery and looks like an ordinary fuse box but it isn't.

Yeah, that is so difficult, you have bought a molested truck, with unknown history and what was done to it. And all unknown. Why don't even known why someone had the intention to throw out the 05 unit and try to fix in an 04 unit.

 

[cerberusiam]

An 04.5 cluster will work with an 05 ECM and vice versa. Early 04 will not work correctly as seen by brake light, ABS, range senor readings, and the TH light coming on. Too many differences in protocols and data stream on the bus. You literally have to swap everything; cluster, ABS, FCM, etc., to make a conversion work. Unless they had an engine fire, which may be why the 04 stuff is there, all they needed to do was swap engines and it would have worked to a degree.

 

[mbpoindexter]

What would you guys suggest as a next move here? I've never asked a mechanic to look at the truck for fear they don't know what they're doing and will charge me through the nose. But that may just be unwarranted paranoia.

Do you think a knowledgeable mechanic would be able to tell me what needs to be swapped out? Is that something that would be easy for them?

I would guess that almost all of the stuff that would have to be switched was switched. But I can't tell exactly the extent of the mismatching.

What would you do?

 

[cerberusiam]

Good luck finding someone to work the electrical nightmare of something that has been partially converted. There is no guarantee of success making it work correctly. A good mechanic won't even touch it, I would be highly suspect of someone that said they could fix it.

It looks like the cluster, ABS, and FCM were not changed. I would start searching salvage yards for an 05 harness and need parts like the TTVA and ECM and get it back to an 05 setup. If you are lucky the only thing you will have to do is put the correct VIN in the replacement ECM.

 

[mbpoindexter]

Good luck finding someone to work the electrical nightmare of something that has been partially converted. There is no guarantee of success making it work correctly. A good mechanic won't even touch it, I would be highly suspect of someone that said they could fix it.

It looks like the cluster, ABS, and FCM were not changed. I would start searching salvage yards for an 05 harness and need parts like the TTVA and ECM and get it back to an 05 setup. If you are lucky the only thing you will have to do is put the correct VIN in the replacement ECM.

I'm looking at the part numbers for everything I can find and they all match for 2004 models. I'm pretty sure that most if not all was converted.

Wouldn't I get codes if there were confusing signals going to the ECM?

Also I checked my codes using the dash key trick and the only one that came up was P0480 which makes sense as the motor was running hot. It seems like as soon as the motor starts running hot the high idle flips on.

 

[cerberusiam]

Does it idle correctly when you first start it? The P0480 means the fan clutch is not setting to where the ECM tells it. At an idle or slow driving under 70 degrees that should not ever get the engine warm enough to jump to high idle, and, if you are moving air flow will keep it low enough high idle won't engage. All things being equal. Maybe thermostat is bad?

Are the Brake and ABS light always on? That is a either a VIN mismatch or bus problem which could indicate other issues. The gear lights are also an indication something is wrong in the setup. In an 05 those are set on the data bus to the cluster, in an 03 an dearly 04 that is direct to the cluster. If you are sure the range sensor is good and the detents are correct there is a comm problem there. The TH light coming on is also an indication that the cluster is not reading bus data correctly, that should not ever be affected by engine temp. Does it work correctly when the engine is not hot? Do you ever get a CEL and the little engine show up on the cluster?

You pulled the cluster and verified it is an 04 part number? An 04 will not work correctly with an 05 bus, and vice versa? How about ABS module and FCM? Those are all showing part #'s for an 04?

 

[mbpoindexter]

It sounds perfect at idle and it fires instantly at crank.

When the engine jumped to high idle I had been driving it around at probably 20-35 MPH for 30 minutes but im in AZ, it was like 95 degrees out. I think I know why the P0480 code is showing up, I was misinformed that an 04.5 harness would work in an 04. I installed what I think is an 04.5 engine harness and the plug connector for the fan clutch is down close to the cam and crank position sensor plugins. But the 04 harness has the fan clutch plug off near passenger side headlight that is not part of the main engine wiring harness. It is part of the harness that runs on top of the engine bay and connects with the 2 plugins near the break fluid container. Please confirm that if you know. So I have mismatched main wiring harnesses where I have 2 plugins for the fan clutch. Maybe that is confusing it. Either way I think ill reinstall the old wiring harness.

I verified the center dash (radio AC switches in cab), ABS module and FCM are all 04 part numbers from a quick google search. I assume cluster is as well.


Going to pull cluster off today and check everything I can find a part number for. If there is anything you can mention that would cause these communications problems please list it so I can be sure to check it.

Thanks again for replying to my messages, whether I figure this out or not I really appreciate the assistance.

 

[mbpoindexter]

I wrote down every part number on an electronic module I could find a checked it.

1543781L02AC - FCM BCM - seems to be interchangeable 02-05
P52010194AC - master cylinder - seems to be interchangeable 03-05
P56051104AF - instrument cluster - seems to be for 2004 specifically
56051947AD - dash wiring 0 seems to be for 2004 specifically
P55056321AC - climate control module - seems to be 03-05
56051040AD - fuse relay center - seems to be interchangeable at least 04-05
P52121408AB - ABS control module - seems to be 2004 specific

ABS and brake lights are not on at idle right now. However the pedal is dead. Only lights on at idle are AIR BAG and seatbelt.

I am replacing the range sensor when it arrives. Seems like the things that are specific for the year are part #s from 2004.

I may have to get another wiring harness to solve the fan clutch thing but I had these problems before with the old wiring harness, just no P0480 code.

 

[cerberusiam]

Try unplugging the fan and AC compressor, those are known issues if the wiring or clutches are compromised.

Also, check the big plug behind the drive side rear fender liner. Make sure no breaks in wires or rubbing occurred and it is clean inside and seated tight.

something is throwing some bad data in the system. You might want to run a cluster check also and see if the cluster has issues. (hold down the trip meter button while turning key to run position) All gauges should cycle, all lights activate, when it is done you will see code sin the odometer window.

 

[mbpoindexter]

oh yeah there are a ton of C-codes. Some I can't find what they mean:

0D 33
21 94
23 94
61 00
64 00
81 00
AB 00
AA 69
AF 00

How do I go about this? Is there one code that is known to set off others? kind of like P2509 for example.

 

[cerberusiam]

Too many codes, now you cannot trust the cluster to display accurate info.

Have you tested the batteries and charging?

 

[mbpoindexter]

Batteries and alternator have been bench tested all good.

To be clear I don't have the P2509 code i was just using it as an example for a code that causes other codes.

 

[cerberusiam]

Have you tried disconnecting AC and fan?

 

[mbpoindexter]

Haven't tried that. I'm replacing range sensor tomorrow I can do that too.

You mean disconnect the fan clutch and compressor? Or the AC in the cab?

 

[cerberusiam]

Disconnect fan at the bottom of the shroud where it easy to get to. Disconnect the AC compressor and check that the wire is not rubbed bare somewhere as it runs up to then harness. Either of those 2 can short out while still working and throw garbage into the system, the AC wire rubbing bare is another know issue.

 

[mbpoindexter]

Do you think it would be worth a try to flash the ECM? If I flash the ECM and insert the VIN of an early 04 truck will that VIN be distributed throughout the entire system?

Could the truck be worse off after a reflash?

 

[cerberusiam]

No, only in the ECM. The other locations need to be set separately with a tool capable of doing it.

 

[mbpoindexter]

Ok just to humor me lets assume I wanted to get the truck back to all 2005. What would need to be changed, and is there a guide you know of that would help me?

I'm trying to see how much it would cost. Right now the truck is 100% a useless paper weight and if the conversion back to 2005 was less than $5,000 roughly I could still break even if I were to sell it.

So I would need:
2005 ECM
engine wiring harness
transmission wiring harness
Dash wiring harness
TTVA added to trans
valve cover harness? I think the injector wiring is different.

Cluster
ABS
FCM


What am I missing? Whats the best way to go about this? Is there a guide? what's your estimate on cost if I do all the labor just need parts?

 

[cerberusiam]

You would have to see if you can find all those parts in a salvage yard to get an idea of cost. The engine harness may be the hard one as it can frequently go with the engine. If you were lucky and gat all the pieces from a single truck with a blown engine likely not even need to rewrite VIN to the components. Finding all that is the question.

 

[mbpoindexter]

Well there is a 2005 dodge 3500 in a salvage yard close to me.

Did I leave anything out form my list that I would need to take?

Seems like everything is extremely cheap anyway I might as well take the whole thing.