Network, generic

U01BA Lost Communication With Park Lock/Pawl Control Module

Check engine lightUsually off
EmissionsNot relevant
Drive cycleNot required
Limp modePossible

With park-by-wire, an electric actuator drives the parking pawl into a toothed wheel on the transmission output; no cable links it to the selector, so the park lock module alone decides when the pawl may drop in, normally only at standstill because at speed it would just ratchet over the teeth. U01BA is set when the transmission or vehicle controller loses contact with this module. No manufacturer documents the code publicly. Ford, for one, has no separate unit: its 2024 OBD description monitors park-by-wire through the gear shift module and the transmission range control module, whose implausible data set non-MIL codes, and the transmission controller reads the park position sensors itself (P07B3–P07BD). Ford's 2012 description shows the general rule for such network codes: a message that does not arrive counts as lost communication (U0140), one that arrives with values out of range as invalid data (U0422). U019E differs, as it concerns the module that selects the whole transmission range. Without confirmed pawl position the car may refuse to leave Park, or it tells the driver to set the electric parking brake, and a warning to secure the vehicle appears. U04BD reports invalid data from the same module.

Likely causes

Connector or wiring fault at the park lock actuator on the transmission
Low 12 V supply, e.g. weak battery
Park lock control module faulty

Symptoms

  • Vehicle will not shift out of Park or Park not confirmed
  • Warning to secure the vehicle with the parking brake

Repair estimate

DifficultyHardWorkshop job
Parts and labour€50–1,500
Time0.5–4 h

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

Parts involved

park lock modulecan bus

Related codes

U04BDU019EU0103U0101

References: fordservicecontent.com, newtonnet.co.uk, en.wikipedia.org, en.wikipedia.org.