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Wideband lambda: sensor, controller and ECU connection

Understand the parts of a wideband system before choosing a sensor or CAN module.

Technical guideInformation · Updated 2026-05-28General selection

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Wideband lambda: sensor, controller and ECU connection

Probe, controller and ECU

A wideband system has a probe, a compatible controller and a signal path to the ECU. Some ECUs contain the required controller; others need an external module.

Analogue output or CAN?

An external controller may send an analogue signal or CAN data. Match the module, protocol and settings to the receiving ECU. A CAN socket alone does not establish compatibility.

Read units and sensor status

Check whether the display shows lambda or an AFR conversion. Read the sensor status alongside the value: a number without its units and operating state can be misleading.

Check the reading before closed-loop control

Record the probe and controller models, then the analogue output curve or CAN settings. Compare the ECU reading with the controller display. Do not use the reading for closed-loop fuel correction during warm-up, a sensor fault or a message timeout.