P2E88

Code

Generic P — Powertrain

Proximity Detection Circuit B Range/Performance

Brand: Generic

Type: P — Powertrain

Views: UK: 19 EN: 43 RU: 25

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Page language: EN

Causes

Failed or damaged proximity/parking sensor B (ultrasonic, radar or infrared type)
Open, short or high-resistance wiring between sensor B and the control module
Corroded, bent or poorly seated connector at the sensor or module
Loss of sensor supply voltage or ground (blown fuse, poor grounding)
Contamination, physical damage or obstruction of the sensor face
Control module fault, software calibration error, or corrupted sensor configuration

Symptoms

Park-assist/proximity warnings or message on dash (e.g., ‘Park Assist Unavailable’)
Illuminated MIL / DTC stored for proximity system
False detections or no detection from one side/area of vehicle
Audible beeps when no object is present or silence when close objects are present
Intermittent operation that may change with vehicle movement or weather (wet/dirty sensor)

What to check

Read DTCs and freeze-frame data with a scan tool; note other related codes
Identify which physical sensor is ‘B’ from vehicle documentation or dealer data
Visually inspect sensor B, its connector, and wiring for damage, water intrusion, corrosion or foreign material
Check fuses and main power/ground for the proximity module
Compare live-data values for sensor B vs. other proximity sensors using a scan tool
Backprobe the sensor connector to verify reference voltage, signal and ground present with ignition on and while exercising the sensor

Signal parameters

Supply/reference voltage typically 5 V (some systems use switched 12 V) — verify OEM spec
Ground continuity to vehicle chassis: low ohms (
Sensor signal: either an analog voltage that varies with distance (approx. 0.5–4.5 V) or a digital/pulsed waveform — should change when an object is introduced/removed
Open-circuit on signal pin or steady out-of-range voltage indicates wiring or sensor fault
Ultrasonic transducer electronics often produce pulsed outputs (check with oscilloscope) — look for repeatable pulses when object is present

Diagnostic algorithm

Verify code and any related codes using a full-function scan tool; record freeze-frame and live data for sensor B.
Identify physical location of sensor B from service literature.
Perform a visual inspection of sensor face, bracket, connector and wiring for contamination, damage, or corrosion; clean sensor surface per OEM guidance.
With connector attached, monitor live data for sensor B while moving a target toward and away from the sensor. Confirm the signal changes compared to a known-good sensor if possible.
With ignition on, backprobe connector: verify reference voltage (per spec), ground continuity, and that signal toggles when object introduced. Repair any missing supply/ground before replacing sensor.
If supply/ground are present and signal is static or out-of-range, unplug sensor and check for short to power or ground on signal pin (measure resistance to battery + and ground).
If wiring and connectors check good but signal still bad, swap with a known-good sensor (or install a new sensor) and re-test to confirm sensor vs. module.
If new sensor still reports fault, inspect/repair harness or consider control module diagnostic/repair or software update at dealer level.
Clear codes and verify proper operation in multiple conditions (wet/dry, different ranges). Document results and return-to-service when confirmed working.

Likely causes

Wiring harness damage or connector corrosion at sensor B
Contaminated or physically damaged sensor B
Sensor electronics failure (internal fault)
Module/software interpretation error or intermittent module power/ground

Fault status

⚠️ Status

Proximity Detection Circuit B Range/Performance — sensor B output is outside expected range or not performing to specification; system may disable park/proximity assist.

🟡 Repair difficulty: Medium

⏱️ Diagnostic time: 1.0 - 2.5 hours