Electronic Codes. Main issue - Service Electronic Throttle

[Morehouse353]

Just bought this truck not long ago. 2018 Ram 1500 3.6L V6. She's got 150xxx miles on her. Was driving great for a few days with a known engine code which was for the coolant bypass valve being stuck open.
Now I've got a new set of codes full of joy..

P26AB Engine Coolant Bypass Valve A Stuck/Open
P26A7 Engine Coolant Bypass Valve A Position Sensor Circuit High
P2681 Engine Coolant Bypass Valve A Control Circuit/Open
P0652 Sensor Reference Voltage B Circuit Low
P0653 Sensor Reference Voltage B Circuit High
P2138 Throttle/Pedal Position Sensor/Switch D/E Voltage Correlation
P2122 Throttle/Pedal Position Sensor/Switch D Circuit Low
P2127 Throttle/Pedal Position Sensor/Switch E Circuit Low

Found these codes using my OBDII Scanner.

Was driving this morning after driving the truck for a few days with no issues. As I was going to park, the service electronic throttle control light switched on and I lost control of my throttle which enabled the truck into "limp" mode (from what I've researched). This problem is a little random. Sometimes after turning the truck off and on again it will go away for an undetermined amount of time, not long though. This problem has persisted well over 15 times today. I've checked the connector that goes to the 3-way coolant valve, and found some blue looking liquid on the connector after unplugging it. I assume this is washer fluid, although nothing really sits above it that involves liquid so I'm not entirely sure what it could be if It's not coolant. After messing with codes and erasing them to see what pops back up, the issue persists. I thought I ran away from the issue for about an hour until she kicked back in. The RPMs flutter at around 1500 and drop slightly if I apply any gas or brake. I do have an electric towing brake system thing attached. I've checked without it plugged in and the issue persists. I'm trying to do what I can without going to the mechanic, although as the codes build in numbers, my hope is diminishing. Looking for some serious help here.

I know very little about all of the electrical systems or really the truck in general. I'm in upstate NY so the weather here isn't that great and I've read that rain can cause these problems. The biggest thing I'm struggling to find is WHERE many of these plugs and switches are located so I can at least look at them and attempt to order new ones.

I did have a camshaft sensor warning after unplugging and re plugging in the 3-way valve circuit (at least I believe that's the correct name) but that went away after clearing codes.

I'm trying to avoid going to dealer ships and mechanics to get this looked at. The problem sounds so simple to fix in my mind but looking for these wires and understanding how to tell what is bad is beyond me. Any inquiry will greatly help me as my search online leads me nowhere when I'm trying to understand where to look and what I should be looking at parts wise.

Trying Many Different Forums Aswell.

 

[huntergreen]

Any chance your battery is not putting out full voltage ?

 

[Morehouse353]

Any chance your battery is not putting out full voltage ?

Honestly wouldn't be completely sure. The reading on the screen shows a quarter over half. Didn't think of that but I'll try to see if I have the tools to give it a look. Doubtful on that though.

 

[huntergreen]

A battery putting out less than optimal voltage can throw a lot of funky codes. Auto parts stores can check battery and alternator usually at no charge. Simplest and cheapest area to start diagnosing.

 

[Morehouse353]

A battery putting out less than optimal voltage can throw a lot of funky codes. Auto parts stores can check battery and alternator usually at no charge. Simplest and cheapest area to start diagnosing.

Checked it out. Battery was on 41 percent life. Had auto one charge it and it was at 92%. Issue still persisted. They said the battery looked like it was still the factory battery.

 

[huntergreen]

I would replace battery and clear codes. They might come back, but it’s still time to change battery.

 

[RamDiver]

Checked it out. Battery was on 41 percent life. Had auto one charge it and it was at 92%. Issue still persisted. They said the battery looked like it was still the factory battery.

A 7-year-old battery at 41% is most likely toast, regardless of what any digital battery tester might indicate. The digital battery load testers used at parts stores are prone to false positives.

The definitive test is to use a toaster-style battery load tester; they're far more accurate.
HarbourFreight sells this easy-to-use tester for $18.

I would always make the effort to test anything before spending money to replace it, especially when the tester is so inexpensive and a great device to own.
I've owned 2 of these for decades.

100 Amp, 6/12V Battery Load Tester

Amazing deals on this 100 Amp 6/12V Battery Load Tester at Harbor Freight. Quality tools & low prices.

www.harborfreight.com

.

 

[Morehouse353]

A 7-year-old battery at 41% is most likely toast, regardless of what any digital battery tester might indicate. The digital battery load testers used at parts stores are prone to false positives.

The definitive test is to use a toaster-style battery load tester; they're far more accurate.
HarbourFreight sells this easy-to-use tester for $18.

I would always make the effort to test anything before spending money to replace it, especially when the tester is so inexpensive and a great device to own.
I've owned 2 of these for decades.

100 Amp, 6/12V Battery Load Tester

Amazing deals on this 100 Amp 6/12V Battery Load Tester at Harbor Freight. Quality tools & low prices.

www.harborfreight.com

View attachment 578388

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Yeah I hear you. I ended up folding and took it to a mechanic because of lack of tools that I own being in the barracks for testing and diagnosing..
they told me that they figured the issue is the circuit to the 3-way coolant valve and I need to replace it. Also told me the accelerator pedal and sensor assembly needed to be replaced. quoted me at 1200 for all of that. Went to O'reilly and got the part for 250 and put it on myself in front of them at the shop and the whole issue was fixed lol. circuit still needs to be replaced but that I have figured out. Battery replacement is on the way. She's definitely deficient. Thanks for the help guys

 

[Morehouse353]

Yeah I hear you. I ended up folding and took it to a mechanic because of lack of tools that I own being in the barracks for testing and diagnosing..
they told me that they figured the issue is the circuit to the 3-way coolant valve and I need to replace it. Also told me the accelerator pedal and sensor assembly needed to be replaced. quoted me at 1200 for all of that. Went to O'reilly and got the part for 250 and put it on myself in front of them at the shop and the whole issue was fixed lol. circuit still needs to be replaced but that I have figured out. Battery replacement is on the way. She's definitely deficient. Thanks for the help guys

Actually back again. This did not in fact solve my issue. It drove well for an hour, and then just like before the lightning symbol came back on and is stuck in limp mode again...
I went last night and bought a brand new duralast battery and put it in, that did not solve my issue. I'm not sure where to even begin now.

 

[Dusty]

Actually back again. This did not in fact solve my issue. It drove well for an hour, and then just like before the lightning symbol came back on and is stuck in limp mode again...
I went last night and bought a brand new duralast battery and put it in, that did not solve my issue. I'm not sure where to even begin now.

If you've got a thin wallet and time on your hands the Throttle Pedal Position circuits A and B are a clue. I'd start checking electrical connectors for the presence of New York green crusties. You'd benefit greatly from a set of wiring diagrams.

Regards,
Dusty
2019 Ram 1500 Billet Silver Laramie Quad Cab 2WD, 5.7 Hemi, 8HP75, 3.21 axle, 33-gallon fuel tank, 18” wheels. Build Date: 3 June 2018. Now at 145331 miles.

 

[RamDiver]

Actually back again. This did not in fact solve my issue. It drove well for an hour, and then just like before the lightning symbol came back on and is stuck in limp mode again...
I went last night and bought a brand new duralast battery and put it in, that did not solve my issue. I'm not sure where to even begin now.

The troubleshooting approach has not changed, only your perception of the fault.

The fault has not changed. Why would you change how to investigate?

A DTC storm is most likely caused by one of two items. A bad battery or a locked-on module spewing garbage data onto the CAN bus. We can start inspecting all connections/wiring to all the modules, isolating modules, rebooting the network after each change to find the problematic module or...

Get your hands on the $18 toaster-style battery load tester and invest 15 seconds in proving the battery is not the cause. Oh, a new battery? The protocol does not change. New batteries are known to be defective from new, the same as any other part on a vehicle.

Imagine if I chose to disengage my brain because I replaced a defective part.
Then I spend countless hours investigating another angle because I am choosing to ignore the signs.

Then, after hours of testing without success, I realize that I ignored testing the most likely suspect, the battery. If this is all about taking the easiest and least expensive approach first, why not prove the battery?

I agree, the battery is less of a suspect than it was, but still an unknown without proof.

Feel free to decide for yourself. I've made a logical case, but it's your truck/time/wallet.

If I were investigating this fault after proving the battery, I would make a list of all the sensors and devices/modules reporting issues and carefully inspect every connector in the wiring path.
If a +12VDC or ground connection is compromised, this might cause trouble with the module.

Remove the connectors, visually inspect that all pins are corrosion-free, not damaged, and properly seated in the connector body. Pins sometimes become dislodged when the connector is assembled, resulting in a poor connection.

When testing the wiring, you will require a digital multimeter to measure DC volts and ohms. HarbourFreight and Walmart sell them for less than $10.
Many members can assist you in learning how to test the wiring.

Or, a module just may have crapped the bed and won't shut up until it is replaced.

If no wiring or connector faults are identified in the above modules, disconnect the power on one module at a time, then disconnect the negative post of the battery for 15 minutes with the headlights on after the disconnection.

The service manual is available below.

Pdf service manual

Has anyone found a 4th generation service manual in a PDF format? If so can you please share the link? I can't get the McFall one to work on my phone. Thanks!

www.ramforum.com

.

 

[Morehouse353]

The troubleshooting approach has not changed, only your perception of the fault.

The fault has not changed. Why would you change how to investigate?

A DTC storm is most likely caused by one of two items. A bad battery or a locked-on module spewing garbage data onto the CAN bus. We can start inspecting all connections/wiring to all the modules, isolating modules, rebooting the network after each change to find the problematic module or...

Get your hands on the $18 toaster-style battery load tester and invest 15 seconds in proving the battery is not the cause. Oh, a new battery? The protocol does not change. New batteries are known to be defective from new, the same as any other part on a vehicle.

Imagine if I chose to disengage my brain because I replaced a defective part.
Then I spend countless hours investigating another angle because I am choosing to ignore the signs.

Then, after hours of testing without success, I realize that I ignored testing the most likely suspect, the battery. If this is all about taking the easiest and least expensive approach first, why not prove the battery?

I agree, the battery is less of a suspect than it was, but still an unknown without proof.

Feel free to decide for yourself. I've made a logical case, but it's your truck/time/wallet.

If I were investigating this fault after proving the battery, I would make a list of all the sensors and devices/modules reporting issues and carefully inspect every connector in the wiring path.
If a +12VDC or ground connection is compromised, this might cause trouble with the module.

Remove the connectors, visually inspect that all pins are corrosion-free, not damaged, and properly seated in the connector body. Pins sometimes become dislodged when the connector is assembled, resulting in a poor connection.

When testing the wiring, you will require a digital multimeter to measure DC volts and ohms. HarbourFreight and Walmart sell them for less than $10.
Many members can assist you in learning how to test the wiring.

Or, a module just may have crapped the bed and won't shut up until it is replaced.

If no wiring or connector faults are identified in the above modules, disconnect the power on one module at a time, then disconnect the negative post of the battery for 15 minutes with the headlights on after the disconnection.

The service manual is available below.

Pdf service manual

Has anyone found a 4th generation service manual in a PDF format? If so can you please share the link? I can't get the McFall one to work on my phone. Thanks!

www.ramforum.com

.

So, after replacing the battery, i brought this up to the shop and told them to follow this method to a degree since I don't currently have these tools. Regardless It ended up not being the battery. The 3-way coolant valve was actually replaced a year or so ago, which was what was throwing all of these codes. Turns out some of these aftermarket coolant valves can throw quite a fit if one thing is wrong, but I believe that is due to there being a lot that runs into just one spot. I had also replaced the 3-way coolant valve circuit but that never fixed anything. It's been driving fine for now, well see if anything pops back up.

All of the codes that I had gotten at one point or another were directly involved with that sensor on the 3-way coolant valve. That's how we started to figure out that this was likely the culprit. After replacing it however, one code still remained, it was the coolant valve A stuck/open. They unplugged the PCM and checked around a bit and I told them whether its the PCM or not, I wont have the money for it and to leave it be. They put some protective layers on wires for free and did a final check right before doing their last test drive for me. After plugging it back in and driving, no codes, no issues. Keeping my eyes peeled. If anything happens, dont worry, i will buy that and check the battery lol.

 

[Marshall]

if you have blue, or green looking water in connectors , that is usally water and corrosion from poor seals on electrical connectors, not washer fluid most times.
check them and clean the contacts if they look dirty, green.
Make sure not to spread the females, that can make for poor connections.
Sometimes saving a few dollars can be expensive.
Make sure all the fuses are fully seated, push them all down.
I have not had any trouble with mine, but I hear fellows say they have come across some that seem to work they up, that can cause poor ccks, low voltage.