Damaged, corroded, or loose wiring and connectors at the camshaft position control module or its CAN bus splice points; Failed camshaft position control module or its internal CAN transceiver; Open or shorted CAN bus wiring between the module and the network backbone; Low battery voltage or poor grounds causing intermittent module dropouts; Water intrusion or heat damage affecting the module or its harness; Aftermarket accessories improperly tapped into the CAN bus wiring; A separate module on the same bus failing and disrupting communication for other nodes

DTC codes / U01xx · Lost communication with a control module / U012E

U012ELost Communication With Camshaft Position Control Module

Q: What does code U012E mean?

Lost Communication With Camshaft Position Control Module. U012E is a generic communication fault indicating that one or more control modules on the vehicle's controller area network (CAN) bus have stopped receiving messages from the camshaft position control module. The computer detects this when the expected periodic CAN frames from that module are missing for a calibrated time, often setting the code alongside a communication bus offline or lost-message fault.

U012E is a generic communication fault indicating that one or more control modules on the vehicle's controller area network (CAN) bus have stopped receiving messages from the camshaft position control module. The computer detects this when the expected periodic CAN frames from that module are missing for a calibrated time, often setting the code alongside a communication bus offline or lost-message fault.

SystemNetwork

Code typeGeneric (all makes)

SeverityMedium

Fix difficultyProfessional

AreaLost communication with a control module

Symptoms you may notice

Illumination of the malfunction indicator lamp (MIL) with no noticeable change in engine performance
Rough idle, hesitation, or reduced power if the camshaft position control module also manages variable valve timing
Intermittent stalling or a no-start condition when communication is lost during cranking
Other unrelated warning lights or module communication codes appearing at the same time
Transmission may default to a limp mode or harsh shifting if the lost module shares data with the powertrain network
Often no symptoms besides the warning light, especially when the fault is intermittent

Common causes, most likely first

Damaged, corroded, or loose wiring and connectors at the camshaft position control module or its CAN bus splice points
Failed camshaft position control module or its internal CAN transceiver
Open or shorted CAN bus wiring between the module and the network backbone
Low battery voltage or poor grounds causing intermittent module dropouts
Water intrusion or heat damage affecting the module or its harness
Aftermarket accessories improperly tapped into the CAN bus wiring
A separate module on the same bus failing and disrupting communication for other nodes

How to diagnose and fix it

Record all stored codes and freeze-frame data, then clear codes and verify whether U012E returns immediately or only after a drive cycle
Inspect the camshaft position control module connectors for corrosion, pushed pins, or loose terminals and check for water intrusion
Perform a voltage drop and resistance test on the CAN high and CAN low wires from the module to the network backbone
Check battery state of charge and clean all engine and chassis grounds that serve the module
Substitute a known-good module of the same part number only after confirming power, ground, and bus integrity
Use a scan tool with live data to monitor CAN bus communication status and confirm the module reappears after repair
Recheck for related codes and perform a road test to confirm the repair under the conditions that originally set the fault

Before you replace the camshaft control module

A weak battery or failing ground can cause this code intermittently without any module being defective, so load-test the battery and inspect grounds before condemning parts.
The camshaft position control module is not present on every vehicle; on some platforms the code may refer to a module that shares the camshaft signal with the engine control module, so confirm the module exists in the network topology.
Aftermarket remote starters, alarms, or dash cameras tapped into CAN wiring frequently disturb bus communication and set U012E without any factory component failure.
A single failed module on the CAN bus can pull the entire network down and cause multiple U-codes, so diagnose the bus as a whole rather than chasing each code individually.
Clearing the code without repairing the underlying connection issue often results in the code returning after several drive cycles, especially over bumps or in wet weather.

Can I keep driving with U012E?

The vehicle is generally safe to drive if it runs normally and only the warning light is on, but avoid long trips or heavy load until the fault is diagnosed. If the engine runs rough, stalls, or other modules stop communicating, park the vehicle and arrange professional diagnosis because loss of camshaft control can affect valve timing and emissions.

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.