Network, generic

U0239 Lost Communication With Entrapment Control Module A

Check engine lightUsually off

EmissionsNot relevant

Drive cycleNot required

Limp modeNo

U0239 means entrapment control module A no longer sends messages. Such a unit watches a power closing panel, a window, sunroof, sliding door or gate, for a trapped object and reverses the motor. In the US, FMVSS 118 sets the reversal limits for windows and roof panels that close without constant switch input; anti-pinch electronics such as Microchip's LIN window lift design or TI's TIDA-01389 sunroof driver detect a jam from motor current or Hall pulses. No manufacturer documents U0239 publicly, so which panel module A protects comes from the maker's documentation. GM's rule applies: status message missing at 9-16 V. U0240 is module B, U053A invalid data from A. Typically one-touch or automatic closing is blocked; no MIL.

Likely causes

Module A without power or ground

Bus wire broken in door hinge or roof harness

Water in the module or plug (door, roof drain)

Entrapment control module A faulty

Symptoms

One-touch or automatic closing does not work
Window or sunroof needs re-initialisation

Repair estimate

DifficultyMediumWorkshop job

Parts and labour€40–700

Time0.5–3 h

Typical range across vehicles; the real cost depends on what the testing finds.

Parts involved

entrapment module acan bus

Related codes

U0240 U053A

References: law.cornell.edu, ww1.microchip.com, ti.com, saabwisonline.com.