Fix U010E: Mechanic’s solutions that WORKED

The code U010E: Lost Communication with Reductant Control Module points out a fault in the vehicle’s emission control system, specifically indicating a communication issue with the Reductant Control Module (RCM). This problem is most likely caused by damaged wiring, faulty modules, incorrect programming, or incompatible aftermarket modifications.

U010E quick overview

Meaning	U010E: Lost Communication with Reductant Control Module
Is it serious?	Yes, this code indicates a communication issue which can affect the vehicle’s emissions system and overall performance.
Possible causes	– Faulty Reductant Control Module (RCM) – Damaged or corroded wiring/connectors – Incorrectly programmed Engine Control Module (ECM) – Aftermarket modifications not compatible with ECM – Faulty sensors or components within the emission control system
How to diagnose?	Check for additional codes to gain more insight into the problem. Inspect wiring and connectors related to the RCM for damage or corrosion. Verify ECM programming to ensure it’s correct for the vehicle. Evaluate the impact of any aftermarket modifications on the emission system and ECM compatibility. Conduct a service regeneration (if applicable) to clear any tamper modes that might be contributing to the issue. Consult a professional if the above steps don’t resolve the issue, as specialized diagnostic tools may be required.

In simpler terms, code U010E means that your vehicle’s computer can’t talk to the part that controls emissions. It’s like having a bad phone connection with an important part of your car. This can lead to your car not controlling its pollution properly, and it might not drive as well until it’s fixed.

How to fix U010E – learn from mechanics

I looked into U010E service cases at iatn.com website where in the private forums the mechanics seek advice from other mechanics. I looked up a bunch of cases to help you decide how to fix your issue and see what would a real mechanic do to solve it.

Case #1: Ram

Vehicle Information

• 2011 Ram 3500 SLT 6.7L

Issue + Repair History

• MIL (Malfunction Indicator Lamp) on
• Code U010e: Lost communication with diesel exhaust fluid control unit
• No previous repair history mentioned

Other OBD2 Codes + Test Results

• Not mentioned

Suggestions to Fix Issue

1. Diesel Exhaust Fluid Control Unit (DCU) might be part of the PCM (Powertrain Control Module) – Dan Habluetzel
2. DCU is a separate module located under the center of the bed, on a plate bolted on top of the center frame cross support – Gilbert Craig
3. Look at the center underside of the bed, as road debris could have damaged the wiring harness – Bradley Miller

Final Fix

• Located the module under the cab, more than half the wiring was butchered, needed extensive rewiring.

Case #2: Ram

Vehicle Information

• 2016 Ram 2500 Limited 6.7L

Issue + Repair History

• MIL on with message: “109 miles till 5mph limit”
• DEF tank full, no communication with DEF module/DEF heater relay circuit
• Fuses checked and okay
• Power and ground at dosing module verified
• New dosing module installed, still no communication
• Only current code is U010e
• Recent battery replacement
• Annual inspection on 12-14-20 with no issues

Other OBD2 Codes + Test Results

• P2509: ECM/PCM power input signal intermittent
• U010e: Lost communication with Reductant Control Module
• P1507: Crankcase Filter Restriction
• P21c4: Reductant heater relay control circuit high
• P238d: Water in fuel sensor B circuit high
• Fuses SCR #75, #19, #69 in TIPM all good
• Dosing module has 2 powers, 1 ground okay with test light

Suggestions to Fix Issue

• Follow step 8 in the diagnostic tree: start disconnecting things that could cause no communication with dosing module, closely monitor ignition cycle on-off times.

Case #3: Ram

Vehicle Information

• 2012 Ram 3500 Laramie 6.7L

Issue + Repair History

• Bought as a total, had run over something, destroying the transfer case
• New transfer case installed, but now has communication codes
• Uncertainty about the need for programming new modules and location of the turbo module

Other OBD2 Codes + Test Results

• U010c: Turbo module communication loss
• U010e: Reductant module lost communication
• U029d: NOx module A lost communication
• U029e: NOx module B lost communication

Suggestions to Fix Issue

• Check for damage in the wiring harness due to the driveshaft incident
• Consider the possibility of crossed bus wires causing communication issues

Final Fix

• Harness damage found at the driveshaft
• Two green/white bus wires were incorrectly twisted together and taped
• Reversed the wires, soldered, and applied heat shrink tubing
• Cleared codes, and no new codes appeared after the repair

Case #4: Chevrolet

Vehicle Information

• 2011 Chevrolet Silverado 3500 HD LT 6.6L

Issue

• No throttle response, “Engine Reduced” message on dash, speed limit at 55mph

Initial Repair Attempts

• Computer (ECM) replaced and programmed as per previous diagnosis
• Injection pump replaced, which resolved the no-start issue
• Added 1 1/2 gallons of DEF fluid, but the problem persisted

Diagnostic Codes

• P245A, P140A, P049D, P205D, P208A, P2047, U029E, U010E, P003A, P2209, P11DB, P20A0, P2471, P2033, P041D, P204C, P242D, P009, P0406, P2495, P0403, P0090

Technician Findings

• DEF system disabled, reductant unplugged
• The exhaust system modified to a straight pipe, no sensors installed
• Vehicle previously purchased from the U.S. without any warning of these modifications

Industry Peer Suggestions

• Check ECM calibration; it might be in tamper mode due to wrong calibration or battery connection issue during ECM disconnection
• Attempt service regeneration and reductant fluid quality test to exit tamper mode
• Ensure correct calibration for the truck; analyze which code sets first and verify fuel data and injector rates
• Re-install the aftertreatment system or find an aftermarket flash for operation without aftertreatment
• The DEF system and emissions modifications could be disabling regen processes
• Check for a “tuner” software in the old PCM for a DPF, DEF, EGR delete etc.
• Restore the engine to stock or find a tuner program compatible with the modifications

Advice	Brief Description of Diagnostic Step
Check for Proper Calibration	Ensure the ECM/PCM is programmed with the correct calibration for the vehicle. Incorrect calibration can lead to various issues, including emission system malfunctions.
Examine ECM/PCM Connections	Verify that all connections to the ECM/PCM are secure and intact, especially after replacement or reprogramming. Poor connections can result in communication faults.
Inspect Wiring Harness	Look for any signs of damage or improper repairs on the wiring harness, particularly if the vehicle has undergone significant repairs or modifications.
Consider Impact of Vehicle Modifications	Acknowledge that modifications to the vehicle’s emission system or exhaust can lead to communication loss with various modules. These need to be compatible with the vehicle’s ECM/PCM programming.
Perform Service Regeneration	If applicable, perform a service regeneration and reductant fluid quality test to help exit tamper mode and resolve communication issues with emission-related modules.
Restore to Stock Condition	If the vehicle has been modified, consider restoring it to stock condition with all original emission systems and sensors in place, as aftermarket modifications can interfere with the vehicle’s normal operation.
Seek Compatible Tuner Program	If the vehicle has been modified and restoring to stock isn’t an option, seek a compatible tuner program that can work with the current modifications without causing communication issues.