Powertrain, generic (extended)

P27E9 Transmission Range Control B Circuit Low

Check engine lightOn
EmissionsNot relevant
Drive cycleNot required
Limp modeNo

P27E9 reports that a line of range control circuit B sits too close to zero volts, pointing to a grounded line or a sensor that pulls its output down. It is not described publicly by any manufacturer. The documented counterpart on channel A is Mitsubishi's P07EA (2022 service manual for a CVT with electric shift): an input under 0.6 V on one of the eight selector sensors for 2.4 s sets it, the cause being a grounded or open sensor line, and the vehicle keeps driving normally. With shift-by-wire there is no mechanical link to fall back on, so redundant channels matter. Look for pinched wiring under the console. The sensor B counterparts in GM's internal range selection are P27F1 and P27F2.

Likely causes

Harness pinched under the center console, shorted to ground
Selector sensor output shorted internally
Sensor supply interrupted, output drops to zero

Symptoms

  • Shift system warning on the display
  • Usually no change in how the car drives

Repair estimate

DifficultyMediumWorkshop job
Parts and labour€60–900
Time0.5–3 h

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

Parts involved

transmission range control actuator bwiring harnesstcm

Related codes

P27E7P27E8P27EAP07EAP27F1

References: mitsubishitechinfo.com, mitsubishitechinfo.com, law.cornell.edu.