B2153

Code

Other B — Body

Rear Echo Sensor Circuit Failure

Brand: Other

Type: B — Body

Views: UK: 20 EN: 33 RU: 22

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Page language: EN

Causes

Open circuit in sensor signal wiring
Short to power or ground on signal or supply wires
Corroded or loose sensor connector or terminals
Damaged or failed rear echo/ultrasonic sensor
Water intrusion or physical damage to sensor housing
Faulty body control module / parking assist module input

Symptoms

Rear parking assist or proximity warning inoperative at rear
Continuous or intermittent beeper or alert tone from parking system
Warning message or lamp for parking assist on dash
Irregular or inconsistent detection of obstacles behind vehicle
Self-test failure or error shown by diagnostic scan tool

What to check

Visually inspect rear sensor(s) and lens for damage, dirt, ice or foreign material
Inspect sensor connector and wiring harness for corrosion, bent pins, damage or moisture
Check related fuse(s) and power/ground at the parking/BCM fuse block
Use a scan tool to read live data for rear echo sensor and run built-in tests if available
Wiggle harness and connectors while observing live data to reproduce the fault (intermittent)
Check for any body control module stored events or related DTCs

Signal parameters

Reference/supply voltage: typically 5 V (some systems use 12 V) at sensor power pin — verify against vehicle manual
Signal output: pulsed/echo waveform — expected swings between ~0 V and ~reference voltage (0–5 V or 0–12 V depending on system) during self-test/active sensing
Continuity: power and ground circuits should show low resistance (
Shorts: signal line shorted to 0 V or to battery voltage is a fault condition (verify with DMM/oscilloscope)

Diagnostic algorithm

Retrieve freeze-frame/data and confirm B2153 along with any related codes using a scan tool.
Perform a visual inspection of the rear sensor, its mounting, lens, and surrounding area for contamination, damage or loose mounts. Clean if necessary and re-test.
Inspect the sensor connector: disconnect, check terminals/pins for corrosion, bent pins, moisture or cement. Clean and reseal connector as required.
With ignition ON, back-probe the sensor connector and verify reference/supply voltage and ground presence per vehicle specification. Do not short pins. Record values.
Check the sensor signal line with a scope or DMM while activating the parking assist (or using self-test) to confirm expected pulsed waveform. If no signal, proceed to wiring checks.
Perform continuity and resistance checks from sensor connector to the parking/BCM connector: look for opens, shorts to ground, and shorts to battery +. Repair any wiring faults found.
If wiring and power/ground are good but signal is absent or abnormal, substitute known-good sensor if available or bench-test the suspect sensor per manufacturer procedure.
If a replacement sensor fixes the issue, clear codes and road-test. If problem persists after sensor replacement, suspect body control/parking module input fault and consider module bench test or replacement following manufacturer diagnostics.
After repair, clear DTCs and verify system operation through multiple activation cycles and a short drive if needed.

Likely causes

Corroded/contaminated connector at rear sensor
Damaged wiring harness (chafe, pinched, rodent damage) between sensor and module
Failed rear ultrasonic/echo sensor
Water ingress into sensor or connector

Fault status

⚠️ Status

The rear echo (ultrasonic) sensor circuit is reporting an electrical fault. The control module detects open, short, or abnormal signal from the rear sensor circuit and has stored DTC B2153.

🟡 Repair difficulty: Medium

⏱️ Diagnostic time: 0.5-2.0 hours