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U0135 – Lost Communication With Differential Control Module Front (OBD2)

U0135 means "Lost Communication With Differential Control Module Front". These codes are stored when a control unit stops receiving messages from a chassis module – ABS/ESP, steering, suspension, parking brake, tyre pressure or differential control.

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U0135 quick summary

Fault codeU0135
MeaningLost Communication With Differential Control Module Front
SystemNetwork / CAN Bus
VehiclesGeneric OBD2
SeverityHigh
Can I drive?Carefully. ABS, ESP, power steering or parking brake functions may be disabled – braking and steering may feel different. Have it checked soon.
Repair cost€0 – €1,500

What 'lost communication' codes with chassis modules mean

Chassis modules such as the ABS/ESP unit, steering angle sensor, power steering, electronic parking brake, ride height and tyre pressure monitoring share data with the engine and gearbox over the CAN bus. If one goes silent, the others store a U01xx code naming it.

Losing communication with the ABS module is particularly common and often comes with ABS, ESP and traction control warnings, a missing speed signal and disabled cruise control. Water ingress into the ABS module connector and corroded grounds are frequent causes.

The diagnosis is the same as for other communication codes: check whether the named module can be reached, then its power, ground and bus wiring.

Symptoms of U0135

  • ABS, ESP or traction control warning lights
  • Speedometer or cruise control not working
  • Power steering or parking brake warnings
  • Tyre pressure warning not working
  • Code stored in several modules

Most common causes of U0135 (most likely first)

Mechanic's Pro Tip

ABS control units with communication faults can often be repaired by specialists – internal solder joint failures are common and much cheaper to fix than buying a new, coded unit.

  1. 1.Corroded or wet connector at the named module

    Most likely

    ABS modules sit low in the engine bay and are exposed to water.

  2. 2.Blown fuse or poor ground

  3. 3.CAN wiring fault

  4. 4.Low battery voltage

  5. 5.Failed module (e.g. ABS control unit)

Step-by-step diagnostic guide

  1. 1

    Check battery and fuses

    Measure battery voltage and check the high-current and control fuses of the named module.

  2. 2

    Scan all modules

    Check whether the named module responds and which modules store the code.

  3. 3

    Check power, ground and connector

    Check the module's supply and ground under load and the connector for corrosion.

  4. 4

    Check the bus wiring

    Measure the CAN lines at the module connector.

    Multimeter: CAN-H about 2.5–3.5 V, CAN-L about 1.5–2.5 V with ignition on.

  5. 5

    Repair or replace and code

    Repair wiring or have the module repaired/replaced; many chassis modules need coding and calibration (e.g. steering angle) afterwards.

Frequently asked questions

Can I keep driving with U0135?

Carefully. ABS, ESP, power steering or parking brake functions may be disabled – braking and steering may feel different. Have it checked soon.

How much does it cost to fix U0135?

Typical repair costs are 0 € – 1500 €, depending on the cause and the vehicle. The most common fixes are: corroded or wet connector at the named module; blown fuse or poor ground; cAN wiring fault. Always confirm the cause with the tests above before buying parts.

Can I drive without ABS communication?

Normal braking works, but ABS and ESP may be disabled. Drive carefully, especially on wet or slippery roads.

Do chassis modules need coding after replacement?

Usually yes – ABS, steering and parking brake modules often need coding and calibration.

What is the difference between U0135 and similar codes?

U0135 belongs to a group of codes for the same component that differ in the type or location of the fault: U0132 – Lost Communication With Ride Level Control Module; U0133 – Lost Communication With Active Roll Control Module; U0134 – Lost Communication With Power Steering Control Module Rear; U0136 – Lost Communication With Differential Control Module Rear; U0137 – Lost Communication With Trailer Brake Control Module; U0138 – Lost Communication With All Terrain Control Module. The tests on this page apply to the whole group; the type of fault tells you where to start.

Related fault codes

This guide is for information only. Working on vehicles can be dangerous — if you are unsure, have the car checked by a qualified mechanic. Values can differ between model years; always check the manufacturer's repair information.