Fault code U1073 – a step-by-step guide to diagnosing and fixing it

The meaning of error code U1073 – SCP (J1850) Invalid or Missing Data for Engine Coolant

U1073: Causes, signs and repairs

Error code U1073 is displayed and the check engine light is on - what does this mean?

The DTC U1073 is recognized by the OBD/EOBD system when a communication error occurs in the vehicle's CAN bus network. This error code indicates malfunctions in data transmission between various control units, in particular between the engine control unit and other important vehicle systems.

What can cause this error code?

Defective CAN bus cable or damaged cables
Corroded or loose plug connections in the CAN bus system
Faulty engine control unit (ECU)
Defective gateway module or communication module
Short circuit or interruption in the CAN bus cabling
Malfunctions due to electromagnetic interference
Faulty termination resistors in the CAN bus
Defective control units of other vehicle systems

What symptoms occur in parallel with error code U1073?

Engine problems: Irregular idling or loss of power
Communication faults: Failure of various electronic systems
Warning lights: Multiple warning lights illuminate simultaneously
Starting problems: Difficulty starting the engine
Diagnostic errors: OBD scanner cannot establish a connection to certain control units
System failures: ABS, ESP or other safety systems not working properly

How to fix the problem of fault code U1073?

Repairing fault code U1073 requires a systematic diagnosis of the CAN bus system.
Checking and cleaning all CAN bus connectors, replacing corroded or damaged connectors
Measurement of the CAN bus voltage and resistance values, repair or replacement of defective cable sections
Replacement of the engine control unit after confirmation of an internal defect by specialist diagnostics
Replacing the gateway module or communication module if a defect is confirmed
Repair of short circuits or interruptions in the CAN bus cabling through professional cable repair
Installation of interference suppression filters or shielding to eliminate electromagnetic interference
Checking and replacing the termination resistors in the CAN bus system

FAQ - Frequently asked questions about DTC U1073

Can I continue driving with error code U1073?

It is not recommended to continue driving with code U1073, as important communication systems may be affected. This can lead to unpredictable failures of safety systems.

How much does it cost to repair trouble code U1073?

Depending on the cause, the repair costs for trouble code U1073 vary between €150 for simple connector repairs and up to €1,500 for the replacement of control units.

How long does it take to diagnose fault code U1073?

The diagnosis of EOBD error code U1073 can take 2-4 hours, as the entire CAN bus system must be systematically checked.

Can error code U1073 be rectified by software updates?

In rare cases, a software update can help, but hardware repairs to the CAN bus system are usually required.

What tools are required to diagnose code U1073?

A professional OBD scanner, a multimeter and special CAN bus diagnostic devices are required for the diagnosis.

Does error code U1073 occur more frequently in certain weather conditions?

Yes, moisture and extreme temperatures can increase corrosion and connectivity problems, causing DTC U1073 to occur more frequently.

Vehicles in which fault code U1073 occurs most frequently

Error code U1073 is a CAN bus communication error and can occur in various vehicle manufacturers, but is most common in the following vehicles:

BMW: 3 Series E90/E91/E92, 5 Series E60/E61, X3 E83, X5 E70 (2004-2013)
Mercedes-Benz: C-Class W204, E-Class W211/W212, S-Class W220/W221 (2002-2014)
Audi: A4 B7/B8, A6 C6/C7, Q5 8R, A3 8P (2005-2015)
Volkswagen: Golf V/VI, Passat B6/B7, Tiguan 5N, Touran 1T (2003-2016)
Ford: Focus II/III, Mondeo IV, Kuga I, S-Max (2007-2018)
Opel: Astra H/J, Insignia A, Zafira B, Vectra C (2004-2017)
Renault: Megane II/III, Laguna II/III, Scenic II/III (2002-2016)
Peugeot: 307, 308, 407, 508, 3008 (2001-2018)

If code U1073 occurs in your vehicle, you should visit a specialist workshop immediately, as CAN bus problems require complex diagnostic and repair procedures. Early repair prevents further damage to electronic components and ensures the proper functioning of all vehicle systems.

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