U1407 – BMW DTC

BMW DTC U1407 – Invalid Data Received From Ambient Air Temperature Sensor

DTC U1407 meaning on BMW

The DTC U1407 code on a BMW indicates that the Engine Control Module (ECM) has detected invalid data coming from the Ambient Air Temperature (AAT) sensor. The AAT sensor is responsible for providing the ECM with information about the temperature of the air entering the engine.

BMW DTC U1407 symptoms

Symptoms of the DTC U1407 code on a BMW may include:

• Check Engine Light (CEL) illuminated on the dashboard
• Inaccurate temperature readings on the climate control system
• Poor engine performance or fuel efficiency

BMW DTC U1407 causes

The DTC U1407 code on a BMW can be caused by various factors, including:

• Faulty Ambient Air Temperature sensor
• Wiring or connector issues in the AAT sensor circuit
• ECM software or hardware problems

BMW DTC U1407 seriousness

While the DTC U1407 code may not cause immediate drivability issues, it is important to address it promptly to prevent potential long-term damage to the engine or emissions system. Ignoring the code could lead to decreased fuel efficiency and performance.

How to diagnose DTC U1407 on BMW

To diagnose the DTC U1407 code on a BMW, a mechanic may perform the following steps:

1. Use a diagnostic scanner to retrieve the fault codes stored in the ECM
2. Inspect the wiring and connectors related to the Ambient Air Temperature sensor
3. Test the AAT sensor for proper operation
4. Check for any software updates for the ECM

How to fix DTC U1407 on BMW

To fix the DTC U1407 code on a BMW, the following steps may be taken:

1. Replace the faulty Ambient Air Temperature sensor
2. Repair any damaged wiring or connectors in the AAT sensor circuit
3. Update the ECM software if necessary

How to erase DTC U1407 on BMW

To erase the DTC U1407 code on a BMW, a mechanic can use a diagnostic scanner to clear the fault codes stored in the ECM. After addressing the underlying issue causing the code, the mechanic can then reset the ECM to clear the code from the system.

Recommended tools & DTC Scanners for BMW

Best Diagnostic App for modern BMWs: BimmerLink

Recommended Bluetooth adapter for Bimmerlink: OBDLink CX

Cable adapter for Bimmerlink: Enet Cable USB Type C

For older BMWs we recommend: Autel AutoLink AL319 (2024 version)

Easy-to-use Multimeter for reliable diagnostics: AstroAI Auto-ranging Multimeter

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