Powertrain, generic · Transmission

P07BE Transmission Park Position Sensor/Switch A/B Correlation

Check engine lightOn
EmissionsNot relevant
Drive cycleRequired
Limp modePossible

With electronic gear selection the park position sensor/switch reports the park request or position. On GM's shift-by-wire selectors (2017 LaCrosse, XT4/XT5, Bolt EV, later SUVs and pickups) it is the P button, read by two redundant analog sensors A and B with separate 'released' and 'pressed' voltage zones. P07BE compares the two redundant sensors in the P button: both report a valid but different state – one pressed, one released – for about 30–60 s, checked only without circuit faults and at low speed. GM's petrol engine modules and ICCM rate it after two trips, the 2018 diesel engine module after one. GM's bulletins note that off-centre pressing or a hand resting on the button can set it; the remedy is control module software or a new shift knob.

Likely causes

Off-centre pressing or a hand resting on the P button
Control module software
One of the two sensors faulty or sticking
Shift knob worn or not seated

Symptoms

  • Check engine light, 'service transmission' or 'unable to shift' message
  • Park cannot be selected by button, or the car will not shift out of P
  • P button illumination off

Repair estimate

DifficultyMediumWorkshop job
Parts and labour€80–600
Time0.5–3 h

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

Parts involved

park position sensorelectronic range selectorsensor wiringtransmission control module

Related codes

P07B5P07BBP07B3P07B9P07B4P07BA

References: gsi.ext.gm.com, gsi.ext.gm.com, gsi.ext.gm.com, static.nhtsa.gov.