U0427

Invalid Data Received From Vehicle Security Control Module

Communication network Generic OBD-II Medium

What it means

U0427 is a network communication code: a module is receiving data from the vehicle security control module that is corrupt, missing, or out of range. This module runs the anti-theft alarm and related sensors. In most cases the impact is a misbehaving alarm, but on vehicles where security is tied into the immobilizer it can affect starting, so it's worth diagnosing rather than ignoring.

Medium

Can I keep driving? Usually drivable, but the alarm may misbehave and on some vehicles the security system can block starting — get it checked.

Common symptoms

What you'll notice

False alarms or the alarm arming/disarming on its own
Security or theft-system warning light on
Remote lock/unlock or panic features behaving erratically
On some vehicles, difficulty starting when security ties into the immobilizer

Common causes

Most likely first

Internal fault in the vehicle security control module sending corrupt dataLikely
Wiring or connector problems on the bus to the security moduleCommon
Low system voltage or a poor ground disrupting the moduleCommon
Faulty hood, door, or shock sensor feeding bad values to the security moduleLess often

How to diagnose & fix

Work through it in order

Scan all modules and record freeze-frame data; clear any lost-communication codes first.
Check battery voltage and grounds — weak power commonly upsets security modules.
Inspect the module connector and bus wiring for corrosion or loose pins.
Check hood, door, and shock sensors that report to the security module.
If wiring, power, and sensors are good, suspect the security control module and confirm with manufacturer tests.

FAQ

Quick answers

Is it safe to drive with U0427?+

Usually yes. The main nuisance is a misbehaving alarm. On vehicles where security ties into the immobilizer, watch for starting problems and get it diagnosed.

Can I just clear U0427?+

It returns while the module reports bad data. Check power and the alarm's input sensors before assuming the module has failed.

Related codes

Often seen with U0427

U0168Lost Communication With Vehicle Security C U0426Invalid Data Received From Vehicle Immobil U0167Lost Communication With Vehicle Immobilize

Read & clear U0427 yourself

Scan your car, confirm the code, and clear it once it's fixed — with OBD DashX on your phone.

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✓ Verified name — SAE J2012 / ISO 15031-6Guidance reviewed by OBD DashX