U010E: Lost Communication With Reductant Control Module

What it means

A control module has lost communication with the reductant control module. Reductant or aftertreatment functions may be affected on vehicles equipped with this system.

At a glance

• Affects emissions; the car can fail an emissions test

How it works

The reductant control module manages functions for the emissions aftertreatment system that uses reductant fluid, where fitted. Other modules expect it to report status over the vehicle network; U010E sets when those messages are not received. The code points to lost communication, not to an empty fluid tank or a specific failed aftertreatment part.

Common causes

Most likely first.

1. Loss of module power or ground
2. Open, shorted, or damaged communication wiring or connector
3. Module or gateway fault

Symptoms

• Warning lights or messages
• Communication faults in other modules
• Aftertreatment warnings or reduced power may occur

How to diagnose it

1. Read and save codes and freeze-frame data from all modules, especially aftertreatment and reductant-related modules, before clearing anything.
2. Check battery voltage and inspect the reductant control module's assigned fuses, power, and ground connections.
3. Inspect its connector and harness for corrosion, fluid or water intrusion, loose pins, and damaged network wires.
4. Use a scan tool to check whether the reductant control module responds and whether related aftertreatment modules report the same network loss.
5. If power and ground are sound but the module stays offline, test the communication bus and gateway route to it to the manufacturer's specification.

Common fixes

• Restore a weak battery and repair poor battery connections.
• Replace a failed fuse or repair the reductant module's power or ground connection.
• Repair damaged network wiring or clean and secure the module connector.
• Repair a confirmed gateway or network fault that interrupts messages to the reductant control module.
• Replace or reprogram the reductant control module only after its power, ground, and network circuits pass checks.

Can I keep driving?

Arrange diagnosis promptly because emissions-system warnings or reduced power may follow, and some vehicles can restrict operation if aftertreatment faults remain unresolved. Avoid long trips if an aftertreatment warning or power limitation appears.