Loose, corroded or damaged connector at the Park position sensor/switch or range sensor; Worn or faulty Park position sensor/switch (internal intermittent contact); Chafed, stretched or broken wiring in the sensor circuit, often where the harness flexes or near the transmission; Selector cable or linkage out of adjustment, so the switch sits on the edge of a position; Water or fluid ingress into the sensor or connector; Low or poor-quality supply voltage or a weak earth affecting the sensor signal; Fault in the transmission or powertrain control unit.

P07B7

Transmission Park Position Sensor/Switch A Circuit Intermittent/Erratic.

Generic
Powertrain
Generic code
Medium severity

How this code is built

P: SystemPowertrain
0: Defined bySAE, the same on every car
7: AreaTransmission
B7: FaultThe specific fault in that area

What it means

P07B7 is the generic code for an intermittent or erratic signal in the Park position sensor or switch 'A' circuit of the transmission. The transmission or powertrain control unit saw the Park signal drop out, jump or change state when it should not have, so the signal does not agree with the selector position or other inputs. Which component is 'A' and how the circuit is arranged depends on the model and transmission.

Symptoms

Engine will not crank, or cranks only intermittently, because the park/neutral signal is unreliable
Gear selector position shown wrongly or flickering on the dash display
Harsh, delayed or missing engagement of Drive or Reverse
Reversing lights or shift interlock behaving erratically
Transmission warning light or malfunction indicator lamp on
Transmission may default to a limited mode or a fixed gear

Possible causes

Loose, corroded or damaged connector at the Park position sensor/switch or range sensorlikely
Worn or faulty Park position sensor/switch (internal intermittent contact)likely
Chafed, stretched or broken wiring in the sensor circuit, often where the harness flexes or near the transmissionlikely
Selector cable or linkage out of adjustment, so the switch sits on the edge of a positionpossible
Water or fluid ingress into the sensor or connectorpossible
Low or poor-quality supply voltage or a weak earth affecting the sensor signalpossible
Fault in the transmission or powertrain control unitrare

How to diagnose

Read all stored and pending codes and note freeze frame data, including selector position and vehicle speed, when the fault set
Check for related codes, such as other range sensor, battery voltage or communication faults, and check technical bulletins for the model
Inspect the sensor connector and harness for corrosion, water, bent or pushed-back pins, rubbing and fluid contamination
Check battery condition and charging voltage, and clean and tighten the relevant earth points
Watch the live selector position and Park signal while moving the selector through every position and wiggling the harness to find dropouts
Inspect the selector cable or linkage for correct adjustment and wear, and confirm the selector lines up with the transmission lever
Test the circuit supply, signal and earth, and check for continuity and shorts, using the manufacturer wiring diagram and specified values
Test the sensor or switch against the manufacturer's specification if the wiring and adjustment check out

How to fix

Clean, repair or replace the damaged or corroded connector and terminals
Repair or replace the damaged section of wiring
Replace the faulty Park position sensor/switch, then adjust or calibrate it if the manufacturer requires
Adjust or replace the selector cable or linkage
Cure the water ingress, then replace any contaminated components
Repair the battery, supply or earth fault, and confirm the control unit software is current if a bulletin applies

Can I keep driving?

Medium severity

The car may be driveable, but an erratic Park signal can cause no-start, wrong gear indication or unpredictable engagement, so get it checked soon. Stop driving if it engages gears unpredictably or the engine stalls or fails to restart reliably.

Guide written by AI from the code's definition. Confirm with a diagnosis before replacing parts.