U046E: Invalid Data Received From Exhaust Gas Sensor Module B

What it means

A receiving module detected implausible data from exhaust gas sensor module B (smart wide-range O2 / lambda module). Lambda or pumping current values fail plausibility checks and are rejected.

At a glance

• Usually lights the warning light of the system that lost communication
• Affects emissions; the car can fail an emissions test

How it works

Exhaust gas sensor module B processes data from a smart wide-range oxygen sensor, including lambda and pumping current, and shares it with other modules for fuel and emissions control. A receiving module sets U046E when module B's sensor data fails plausibility checks and is rejected.

Common causes

Most likely first.

1. Module internal fault or sensor input drift
2. Software version mismatch after replacement
3. Gateway module routing CAN messages incorrectly

Symptoms

• Multiple warning lights may illuminate
• Affected modules may go into limp mode or shut down
• Specific functions inoperative depending on module
• Diagnostic tools may show communication faults

How to diagnose it

1. Scan all modules and save freeze-frame data and oxygen-sensor or emissions codes to determine when module B's data was rejected.
2. Compare live lambda and pumping-current readings from exhaust gas sensor module B with engine operating conditions and any available readings from the other sensor module.
3. Inspect module B's sensor wiring and connectors near the exhaust for heat damage, chafing, corrosion, or loose terminals.
4. Check for exhaust leaks near the sensor and related CAN or gateway faults that could affect the reported data.
5. If wiring and exhaust checks pass, test the sensor and module B inputs and verify software compatibility using the manufacturer's procedure.

Common fixes

• Repair heat-damaged, chafed, or poorly connected module B sensor wiring.
• Repair an exhaust leak near the sensor if it is affecting readings.
• Correct module software or configuration after sensor or module replacement.
• Replace a faulty wide-range exhaust sensor or module B if testing confirms the source of implausible data.
• Repair a gateway or CAN network fault if it is corrupting or interrupting module B messages.

Can I keep driving?

Short, gentle driving may be possible if the engine runs normally, but avoid hard acceleration and prolonged trips because fuel control and emissions monitoring may be affected. Stop driving if the engine runs roughly, loses power, or the warning is accompanied by a flashing engine light.