(P)ECM Code 606

[Silver Tex]

Hello,
I had picked up a new (to us) 5th wheel and had 2 6v batteries installed in series in lieu of 12v parallel. Pulling it home from Utah, I live in Colorado, about an hour into the pull the CEL came on. Checked the code through my Smarty Touch and found it to be P0606. After reading what the code meant and having to pull another 500 miles, I was a little concerned. I checked the batt connections for tightness and cleanliness, the truck was still running fine, but the code would not clear.
Pulled a bit longer up the Paisley grade (?) toward Park City and was thinking what was different? Pulled over again and pulled the disconnect on my 5er batteries, tried to clear code - it did and never had a problem since. Anyone have a thought on this? I’d like to have the alternator in the truck help with charging but not at the risk of the (P)ECM. I don’t have a batt. Isolator on the truck. I’m thinking some sort of unhealthy feedback coming through the trailer connection. Would an isolator help or do I just leave my batt’s disconnected while pulling?
I appreciate you staying with me through the length of the post and look forward to any comments.

Thank you,
Scott.

 

[Tuesdak]

If you understand Trons then have a go at it. Otherwise you need an automotive electrical shop. This is from the standpoint you have a voltage problem causing the ECM to brownout on low voltage and fail. It may not be the case and you simply have a bad ECM.

Start with testing the truck's batteries separately in case one failed. Battery connections being clean and tight are critical for the ECM.

A used 5th wheel is an unknown for the trailer electrical plug. You need to verify the 12v charging connector in it and the ground wires are in the proper spots. Wiggle test to make sure they are not loose in the 5th wheel's connector plug. Any corrosion on the truck connector plug? The truck ground from the trailer plug is worth cleaning. Then grounds on the 5th wheel connector plug. Do all the lights work properly on the 5th wheel when plugged in? Any dimming of the running/parking lights say when a turn signal is flashing? (Bad ground if so.)

Does the 5th wheel have a solar setup?

Are you measuring 12v on the 5th wheel rather than an OOPS! of 6V battery setup?

 

[AH64ID]

That code is for an ECM internal error, and likely means you need a new ECM. In all likelihood it was just timing with the 5th wheel, as that shouldn’t have any effect on the internal test of the ECM.

 

[Silver Tex]

Would the truck be running fine for the past 2 months if the ECM was toast?
Thanks for he input!

 

[Silver Tex]

Would the truck be running fine for the last 2.5 months if the ECM was toast?
Thank for the input!
Where is best place to pick up ECM if needed.
Scott.

 

[Silver Tex]

If you understand Trons then have a go at it. Otherwise you need an automotive electrical shop. This is from the standpoint you have a voltage problem causing the ECM to brownout on low voltage and fail. It may not be the case and you simply have a bad ECM.

Start with testing the truck's batteries separately in case one failed. Battery connections being clean and tight are critical for the ECM.

A used 5th wheel is an unknown for the trailer electrical plug. You need to verify the 12v charging connector in it and the ground wires are in the proper spots. Wiggle test to make sure they are not loose in the 5th wheel's connector plug. Any corrosion on the truck connector plug? The truck ground from the trailer plug is worth cleaning. Then grounds on the 5th wheel connector plug. Do all the lights work properly on the 5th wheel when plugged in? Any dimming of the running/parking lights say when a turn signal is flashing? (Bad ground if so.)

Does the 5th wheel have a solar setup?

Are you measuring 12v on the 5th wheel rather than an OOPS! of 6V battery setup?

I hadn’t responded to this.
Will check batteries and alternator.
All lights on both rigs worked fine last time it was hooked up (2 months ago). No dimming as you described, except perhaps if the grid plate is cycling. No solar - yet.
I checked when I picked it up from the dealer that the new 6v batts were installed properly. Everything in the 5er works fine under battery power.
I’ll go through the plugs as that is a good idea.

Just started the truck as its been sitting outside for a week (the whole Santa’s workshop thing). During grid plate cycle, it was showing well below 8 on the factory amp meter. Rolled over real slow but ultimately started. Checked batts under charge, both at ~15.26v. This seemed a little high but maybe not. With truck off, both batts at 12.5v +/-. Will check connections and water tomorrow.

Thanks!
Scott.

 

[AH64ID]

It just depends on what the ECM thought was bad when it tripped the P0606. You didn’t mention a year, so this is from an 05 FSM.

Notice there aren’t any trouble shooting procedures, just replace.

But to play along with the 5er causing the issue have you attempted to recreate it with the trailer?

 

[Silver Tex]

It just depends on what the ECM thought was bad when it tripped the P0606. You didn’t mention a year, so this is from an 05 FSM.

Notice there aren’t any trouble shooting procedures, just replace.

View attachment 117497

But to play along with the 5er causing the issue have you attempted to recreate it with the trailer?

06 2500 4X4
I have not attempted to recreate. The truck batts are less than 4 years old (Napa Gold). I realize that doesn’t mean much. What do you think about 15.25v (volt meter reading batter posts while truck running). Seem high?

Yes, I see just replace. Looks like about $700 - $800? Will continue to trouble shoot and replace if must.

Will update on status.

Thank you!
Scott.

 

[Crunch]

Yes, I see just replace. Looks like about $700 - $800? Will continue to trouble shoot and replace if must.

You can send it to SIA Electronics in Illinois for repair. They will fix it for $250 and guarantee it for life. If they can't fix it they will provide you with options. It pretty much takes a full two weeks before you get it back, so be prepared to be without your truck for that time.

 

[AH64ID]

06 2500 4X4
I have not attempted to recreate. The truck batts are less than 4 years old (Napa Gold). I realize that doesn’t mean much. What do you think about 15.25v (volt meter reading batter posts while truck running). Seem high?

Yes, I see just replace. Looks like about $700 - $800? Will continue to trouble shoot and replace if must.

Will update on status.

Thank you!
Scott.

If you think it was tied to the trailer then you should attempt to recreate it. The trailer shouldn’t cause any issues, so it would be good to know before camping season.

Low voltage to the ECM is a different code, and I’ve seen it from dead batteries.

What’s the temp? 15.25 seems a little high, but if it’s COLD it might not be.

Are both batteries reading the same?

 

[Silver Tex]

If you think it was tied to the trailer then you should attempt to recreate it. The trailer shouldn’t cause any issues, so it would be good to know before camping season.

Low voltage to the ECM is a different code, and I’ve seen it from dead batteries.

What’s the temp? 15.25 seems a little high, but if it’s COLD it might not be.

Are both batteries reading the same?

Hello John,
Yes, it was relatively cold and both batteries read the same. I’m going to disconnect, pull and put in shop under a charge and see how they test. It will be a good opportunity to clean the terms up good as well and check water levels in cells.

Thanks and have great day!
Scott.

 

[Silver Tex]

You can send it to SIA Electronics in Illinois for repair. They will fix it for $250 and guarantee it for life. If they can't fix it they will provide you with options. It pretty much takes a full two weeks before you get it back, so be prepared to be without your truck for that time.

Thanks Crunch,
That sounds like a great option. My truck is not a daily driver so the 2 weeks won’t be a problem.
I appreciate all the feedback!
Scott.

 

[Ozymandias]

Just started the truck as its been sitting outside for a week. Checked batts under charge, both at ~15.26v. This seemed a little high but maybe not. With truck off, both batts at 12.5v.

Thanks!
Scott.

I would say you need new batterys. The 15.26V tells my that your truck tries it's best to charge the batterys.
The 12.5V tells that the batterys dont take the charge.
Now add a trailer with also demanding batterys and your out off spec.

Batterys with 12.5 are anyways very bad, you want to see 13.2 shortly after shutting down the engine and 12.8/9 after a couple hours resting.
These are the numbers that count.

 

[Ozymandias]

What do you think about 15.25v (volt meter reading batter posts while truck running). Seem high?

Thank you!
Scott.

No I see that a lot in great cold. 14.8 in Summer, 15.2 during winter.
That's why one wants to check the specs for a battery that is planned to be installed into the truck.
By far not every Battery can handle that high of a charging voltage, and that leads to premature failure.

 

[Silver Tex]

No I see that a lot in great cold. 14.8 in Summer, 15.2 during winter.
That's why one wants to check the specs for a battery that is planned to be installed into the truck.
By far not every Battery can handle that high of a charging voltage, and that leads to premature failure.

As promised. I have had the batteries checked and both tested good. I have cleaned all post and connections. I checked the charging circuit and it is running at ~14.5v. I have put the ECM voltage as part of my Smarty Touch dashboard. It is running at ~14.7-14.8v. Everything seems to all in order. Any further thoughts????
Thanks all and Merry Christmas!
Scott.

 

[p-Bar]

Don't charge your 5er batteries off the truck. If your 5er batts. are low and truck batts. aren't you will cause overcharging.

 

[AH64ID]

Don't charge your 5er batteries off the truck. If your 5er batts. are low and truck batts. aren't you will cause overcharging.

I can honestly say I've never experienced that, nor do I agree with it.

The alternator will only put out the amperage required to maintain the set voltage. The truck maintains voltage based mainly on temperature, not state of charge. That voltage is the same regardless of battery state of charge (assuming the alternator can maintain the set voltage).

If the truck batteries are charged they simply don't absorb any additional amperage, but the camper batteries will at the rate allowed by the wire (which is never great, 15A is the most I've ever seen).

 

[p-Bar]

We have problems with 2 batteries in our trucks . If one goes bad and ECM says keep charging and over charge the other battery.

 

[AH64ID]

We have problems with 2 batteries in our trucks . If one goes bad and ECM says keep charging and over charge the other battery.

That's a different scenario than low trailer batteries, especially when you consider the small wire and long run to the trailer batteries.

The good battery doesn't always overcharge either, it depends on the kind of failure, what voltage the ECM still sees, and which battery fails. Often the bad battery drags the good battery down with the engine off and that results in a bad battery.

 

[Tuesdak]

Eliminating the RV as an X factor...

Trust, but Verify, the 5th wheel when disconnected from truck is at 12v on an internal outlet.

Check the RV batteries for tight connections and cable condition, every inch. (Same for truck positive cables.) One battery positive cable short was causing all kinds of ECM nightmares on a rig, but, didn't burn it to the ground. We were down to inspecting every inch of wire at that point. Under load the engine leaned into the cable causing a short, would loose ign and power and unshort, then fire back up violently.

Probe the following two connections on the truck and 5th wheel:
+ Auxiliary: looking for battery voltage in reference to A ground.
Ground : test for voltage in reference to A Ground first and then resistance that should be "0".

"A Ground" is any ground on the 5er or truck under test.

Then measure battery voltage on each and write down.
Plug in the 5th wheel and remeasure and write down.

Start the truck and remeasure the battery voltage on the truck and 5er and write down.

Next with the truck running measure voltage between "A Ground" on the truck and "A Ground" on the 5th wheel. We are looking for a possible bad ground with this test.

Now do a wiggle test on the wire coming out of the trailer plug and at the 5th wheel. We are looking for loose wires, broken wires, or shorts in the plug or wire near it. Measure the ground voltage between them as above and the charging voltage at the RV while doing this test. I use an analog meter as digital won't show a problem aka a needle jumping during wiggle tests.

Verify all the lights work properly like turn signals etc on the 5th wheel. Looking for any wiring screw-ups.

Someone will have to chime in on specific Dodge setups: I am used to installing a 30A breaker under the hood for the Aux trailer battery charging. Sometimes it is off a larger fuse to the breaker.