Damaged or corroded wiring in the CAN bus circuit between the ECM and the emissions-critical module; Loose, backed-out, or corroded connector pins at either end of the affected bus segment; Failed emissions-critical module that has stopped transmitting on the network; Blown fuse or poor power/ground feed to the emissions-critical module, causing it to go offline; Failed ECM or gateway module that cannot receive or route the messages correctly; Aftermarket electronic device wired into the CAN bus that is corrupting or interrupting communication; Water intrusion or chafed harness in a known routing area that damages the bus wiring

DTC codes / U01xx · Lost communication with a control module / U0113

U0113Lost Communication With Emissions Critical Control Information

U0113 means the engine control module (ECM) or another primary controller has lost communication with a module that broadcasts emissions-critical control information over the vehicle's controller area network (CAN) bus. The computer detected that the expected periodic messages from that emissions-critical source stopped arriving within the required time window, so it flagged the communication fault and may illuminate the check engine light.

SystemNetwork

Code typeGeneric (all makes)

SeverityMedium

Fix difficultyProfessional

AreaLost communication with a control module

Symptoms you may notice

Check engine light illuminated, often with no other noticeable symptoms besides the warning light
Rough running or reduced engine performance if the missing emissions data affects fuel or air control
Transmission may shift harshly or stay in a default gear if the lost module also shares drivetrain data
Intermittent stalling or hesitation when the communication dropout is sporadic
Other warning lights such as ABS or traction control illuminated if the same bus segment is affected
Failed state emissions inspection because the readiness monitors cannot complete

Common causes, most likely first

Damaged or corroded wiring in the CAN bus circuit between the ECM and the emissions-critical module
Loose, backed-out, or corroded connector pins at either end of the affected bus segment
Failed emissions-critical module that has stopped transmitting on the network
Blown fuse or poor power/ground feed to the emissions-critical module, causing it to go offline
Failed ECM or gateway module that cannot receive or route the messages correctly
Aftermarket electronic device wired into the CAN bus that is corrupting or interrupting communication
Water intrusion or chafed harness in a known routing area that damages the bus wiring

How to diagnose and fix it

Connect a scan tool and record all stored and pending codes, then verify whether other modules on the same bus are also reporting communication faults
Inspect the battery, charging system, and main fuses to confirm stable voltage to all control modules before chasing network faults
Locate and inspect the CAN bus connectors and wiring between the ECM and the emissions-critical module for corrosion, looseness, or chafing
Measure CAN bus resistance and voltage at the diagnostic link connector to confirm the bus is intact and not shorted or open
Check power and ground at the emissions-critical module connector with a multimeter and a load test to confirm the module is being powered correctly
If wiring and power are good, substitute a known-good module of the same part number or perform a bidirectional communication test to confirm the module is offline
Clear codes and perform a road test with the scan tool recording live network data to confirm the communication fault does not return

What the emissions-critical label really means

The phrase emissions-critical control information does not point to one specific module; it refers to whichever module on that vehicle broadcasts data the ECM needs for emissions control, so the actual failed component varies by make and model.
A common misdiagnosis is replacing the ECM first, when the real fault is a single corroded pin in a connector that costs far less to repair and is often found by wiggling the harness while watching live data.
This code can set intermittently from a low battery or a weak ground rather than a hard wiring failure, so clearing it after a battery service and road testing is a valid first step before any parts are replaced.
Aftermarket alarms, remote starters, or plug-in fleet trackers tapped into the CAN bus frequently cause U0113 because they introduce noise or back-feed voltage that disrupts the bus messages.
U0113 often appears alongside other U-codes on the same bus segment, and the pattern of which modules are missing tells you more about the fault location than the code itself.

Can I keep driving with U0113?

You can usually drive the vehicle to a repair shop, but avoid long trips or heavy load because the lost emissions data can affect fuel control and may cause poor running. If the engine runs rough, stalls, or multiple warning lights are on, stop driving and have the vehicle towed to prevent damage.

Tools that help

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Guidance is general and written for all OBD-II vehicles. Exact tests and values vary by model, so confirm the fault before replacing parts.