P202B-Reductant Tank Heater Control Circuit Low
Wiring Diagram is attached

Diagnostic Test

1. ACTIVE DTC

Turn the ignition on for one minute, engine not running.

With the scan tool check for active DTCs.

Is the DTC active?

Yes

• Go To 2

No

• Perform the INTERMITTENT CONDITION - 6.7L. (Refer to 28 - DTC-Based Diagnostics/MODULE, Powertrain Control (PCM) - Standard Procedure)(Refer To List 1).

2. CHECK THE DEF TANK HEATER SUPPLY CIRCUIT FOR A SHORT TO GROUND

Turn ignition off.

Disconnect the DEF Supply Pump assembly harness connector.

Disconnect the DEF Dosing Control Unit C2 harness connector.

Measure the resistance between ground and the DEF Tank Heater Supply circuit at the DEF Supply Pump assembly harness connector.

Is the resistance above 10k Ohms?

Yes

• Go To 3

No

• Repair the DEF Tank Heater Supply circuit for a short to ground.
• Perform the POWERTRAIN VERIFICATION TEST - 6.7L. (Refer to 28 - DTC-Based Diagnostics/MODULE, Powertrain Control (PCM) - Standard Procedure)(Refer To List 1).

3. CHECK THE DEF TANK HEATER SUPPLY CIRCUIT FOR AN OPEN/HIGH RESISTANCE

Measure the resistance of the DEF Tank Heater Supply circuit between the DEF Supply Pump assembly harness connector and the DEF Dosing Control Unit C2 harness connector.

Is the resistance below 5.0 Ohms?

Yes

• Go To 4

No

• Repair the DEF Tank Heater Supply circuit for an open or high resistance.
• Perform the POWERTRAIN VERIFICATION TEST - 6.7L. (Refer to 28 - DTC-Based Diagnostics/MODULE, Powertrain Control (PCM) - Standard Procedure)(Refer To List 1).

4. CHECK THE DEF TANK HEATER RETURN CIRCUIT FOR AN OPEN/HIGH RESISTANCE

Measure the resistance of the DEF Tank Heater Return circuit between the DEF Supply Pump assembly harness connector and the DEF Dosing Control Unit C2 harness connector.

Is the resistance below 5.0 Ohms?

Yes

• Go To 5

No

• Repair the DEF Tank Heater Return circuit for an open or high resistance.
• Perform the POWERTRAIN VERIFICATION TEST - 6.7L. (Refer to 28 - DTC-Based Diagnostics/MODULE, Powertrain Control (PCM) - Standard Procedure)(Refer To List 1).

5. DIESEL EXHAUST FLUID TANK HEATER

Reconnect the DEF Dosing Control Unit C2 harness connector.

Connect a jumper between the DEF Tank Heater Supply circuit and the DEF Tank Heater Return circuit at the DEF Supply Pump assembly harness connector.

Turn ignition on.

With a scan tool, View DTCs.

Does the scan tool display DTC P202C as active or pending and P202B as stored with the jumper in place?

Yes

• Replace the DEF Supply Pump assembly in accordance with the service information.
• Perform the POWERTRAIN VERIFICATION TEST - 6.7L. (Refer to 28 - DTC-Based Diagnostics/MODULE, Powertrain Control (PCM) - Standard Procedure)(Refer To List 1).

No

• Replace the DEF Dosing Control Unit in accordance with the service information. (Refer to Emissions Control/Diesel Exhaust Fluid Emissions/UNIT, Diesel Exhaust Fluid Dosing Control - Removal).
• Perform the POWERTRAIN VERIFICATION TEST - 6.7L. (Refer to 28 - DTC-Based Diagnostics/MODULE, Powertrain Control (PCM) - Standard Procedure)(Refer To List 1).

 

P20E8-(Diesel Exhaust Fluid) Reductant Pressure Too Low
This one is quite involved, requiring the ability to perform a DEF Reductant Doser Prime Override Test with a scan tool, testing for hydrocarbons in the DEF (dipping a test strip into the tank), going for lengthy test drives, remove DEF injectors to look for deposits, remove tubes to check for obstruction, basically doing a very in-depth visual inspection of the entire system and if visual inspections fail, those components get replaced. Looking at what my bro went through, it seems if one part fails the "inspection", they just replace the entire system.

 

Thank you for posting that. It cannot hurt to pull the injector out for a cleaning as well. Add that to the list to check.

 

New to the group, looking for a little assistance. I have a 2015 6.7 RAM 3500 with CEL indicating the diesel exhaust fluid injector. I ohms checked the injector, 12.35 ohms. I am attempting to remove the injector and no wrench or socket appears to fit the bolts (pic attached). I am the original owner and the injector has never been removed. The head appears to be conical shaped, is there special tool? Appreciate any recommendations.

 

You're welcome! Hopefully it gets you going in the right direction.

Sent from my SM-G955U1 using Tapatalk

 

Can somebody help me I have a CTS to edge juice with attitude I’ve done the EGR delete I just got my 5 inch exhaust from the turbo back that I have not installed yet I don’t know how to delete the DEF system and not have any issues Can someone point me in the right direction on what I need to do to make everything work

 

Brian, I had almost the exact scenario just after Xmas. Heater side of the pump assy died. I’ve also had an empty def tank showing when it actually was half full a couple times. Got one of the last pumps in FCAs inventory just before New Years. Were back ordered till April but you should be able to get a new pump for little over half what they’re quoting you. PM me with how I’d tune it if you want to go that direction.

 

I don't mean to hijack this thread, but asking the same question when there are already so many is taboo.

My situation seems hardly unique, but I've not seen a complete answer to my problem.
2015 2500 Megacab threw the P20E8 code and told me to make haste to my dealer.
Reviewing this and other forums, along with YouTube showed that many have had success removing the injector at the SCR and cleaning crusty deposits off the injector and in the opening where the injector lives. I did that. The amount of buildup on my injector and the hole where it lives was nothing spectacular. Truck only has 82k miles on it. Rarely goes anywhere cold. Yes, in February this year we got thumped with 9 days straight subzero temperatures, very rare for Texas.

Troubleshooting on my part includes using my AlfaOBD to clear the code. It merrily comes back after a short drive.
P20E8 is the only code I have.

Removing the injector and starting the truck results in the injector spraying an incredible cloud of DEF for about 15 seconds, then stopping for about 15 seconds and turning on again for 15 seconds. It continues this until I've seen enough DEF running down my driveway and shut the truck off.
Obviously my pump is working and the injector is not having a problem. Injector was also ohmed out to 12 ohms, so there is no mistaking my injector is OK.

Going into the diagnostics on my AlfaOBD, I have a graph for Diesel Exhaust Fluid line pressure (kPa).
Starting the truck and monitoring that, I get 0.00 kPa.
Before I jump to the conclusion my pressure sensor is bad (too late) I had a coworker with a 2017 come over and we checked his Diesel Exhaust Fluid Line Pressure at idle and with him driving around. 0.00 kPa is the result.

Has anyone here had success with AlfaOBD measuring Diesel Exhaust Fluid Line Pressure?
I hate to shotgun this problem because that just doesn't sit well with me.

Telling me to delete the truck is wasted words. While I plan to do that, I seriously want to know that the f^&* is going on here.

One frustrating commonality on this issue is not just the amount of folks that get the problem, but few come back and say what the ultimate repair was.

Any advice on troubleshooting is welcome. Any members with AlfaOBBs - hit me up. I'd love to discuss.

 

Welcome to the internet where anyone can ask questions, get help, and choose if they will follow up with any results. You could take it to a shop that has the proper diagnostic tools as AlphaOBD and even AutoEnginuity doesn't do it all. I even inquired with AE about a certain function and asked about adding it in a future release and it seems that they are really inept about certain diagnostic functions despite creating a fairly powerful scan tool. Instead of addressing what I inquired about, they simply reply with "but it can do this" or to send you over to the file that supposedly includes everything it can do.

The code you have is a crappy code that Chrysler didn't really seem to have a foolproof way to diagnosis...that's not the only one in these trucks.

If AlphaOBD can't run the one test I mentioned in my post above, then take it to a reputable shop or do what you say you are planning on doing and be done with it.

2010 Black 6.7L MegaCab 2500 SLT, 4x4, Auto

 

Sometimes it may not be a limitation of the scan tool, but the level of support provided by certain module revisions, sadly. One module might allow a certain function but a prior module may not. The ECM revision may allow certain types of tests to be performed, but it may require access by tools that Alpha and AE can't provide for whatever reason. Chrysler is also notorious for locking out certain levels of diagnostics that only their Wi-Tech can perform. Although, I think with the push from groups such as the Right to Repair, it seems like certain scan tools might be able to provide some dealer-level diagnostics per the Mopar Essentials website and they now have a Wi-Tech system available for the aftermarket, all at a premium.

 

Did u find a fix for this? I got the 208p code and I took it to the shop and they suggested the shot gun approach, for 6 k. F that took it home to start replacing **** myself. So I got a new injector, no luck, I replaced the def pump and feed /heater line, dropped removed and cleaned out my tank and reseated all wiring harness connections on the def system. Re ran it today and my "def issue see dealer"message went away on my dash. I cleared the code manually and after driving it for about 30 miles I stopped and truck...ran into naka for something and and I stared it t back up the same message popped back up.all that's left is the control module andpump wire harness....I sont have a fancy odb2 so ive been replacing parts slowly but damn this sux I did have some other codes that haven't come back p2048 and p218f so I guess that's a small win . thoughts?!