B1825

Code

Other B — Body

Wiper Rear Park Sense Input Circuit Short To Ground

Brand: Other

Type: B — Body

Views: UK: 18 EN: 26 RU: 23

AI status

Completed

ready

Completed 100%

Page language: EN

Causes

Damaged/chafed wiring harness (tailgate/hinge area) shorted to ground
Corroded or water-intruded rear wiper motor or park switch assembly
Damaged connector (pins pushed out, bent, corrosion, water)
Faulty rear wiper park switch inside the motor assembly
Incorrect or poor ground repair/aftermarket wiring touching the park sense circuit
BCM input circuit failure (less common)

Symptoms

Rear wiper will not park correctly or stops in mid-sweep
Rear wiper inoperative or intermittent operation
Wiper may stop and not return to rest position
Related warning or DTC indicator stored in BCM
Possible blown fuse or erratic behavior of rear wiper circuit

What to check

Visual inspection of rear wiper motor, connector, and harness for damage, corrosion, or water entry
Verify DTC stored in BCM and note freeze-frame/conditions
Disconnect rear wiper motor/switch connector and check if DTC clears (helps isolate harness vs module)
Back-probe the park sense input at the connector and at the BCM harness to measure voltage and continuity
Check for continuity to chassis ground on the park sense conductor with connector disconnected
Wiggle test harness while monitoring voltage / DTC to reproduce intermittent shorts

Signal parameters

Expected idle/open (no park switch to ground): ~5 V (or module pull‑up voltage) on park sense input (verify vehicle spec)
Expected park/activated (switch closed to ground): ~0 V (ground) when park switch is intentionally closed
Short to ground condition: input measured ≈0 V continuously when it should be high
Resistance from park sense conductor to chassis ground with connector disconnected: normally very high (kΩ or open); a short will show low resistance (

Diagnostic algorithm

Verify customer complaint and retrieve DTC B1825 and any related codes from BCM; record freeze-frame data.
Perform a detailed visual inspection of rear wiper motor, connector, tailgate harness, grommet, and hinge area for damage, corrosion, or water intrusion.
Disconnect the rear wiper motor/switch connector. Clear the DTC and cycle ignition. If the code does not return, suspect wiring or the motor/switch assembly.
With the connector disconnected, measure resistance from the park sense terminal in the vehicle harness to chassis ground. If low resistance (
Back‑probe the park sense input at the motor connector with ignition ON and measure voltage. Normal/open should show pull‑up voltage (~5 V). If it reads ~0 V with connector still connected, a short to ground is present on that circuit.
If voltage is normal with connector disconnected but drops to 0 V when connected, suspect the rear wiper motor/park switch assembly. Bench test or substitute a known-good motor/switch to confirm.
Perform a wiggle test along the harness while monitoring the input voltage or DTC status to locate intermittent shorts (pay special attention to hinge/grommet areas).
Repair damaged wiring (replace section or install pigtail), clean/repair/replace corroded connectors, or replace the rear wiper motor assembly if the internal park switch is faulty.
After repairs, clear codes and confirm rear wiper parks and operates correctly over multiple cycles; recheck for stored codes.

Likely causes

Wire insulation rubbed through where harness passes through tailgate hinge and contacting body ground
Water entry into rear wiper motor connector causing pin-to-ground short
Pinched harness when tailgate was serviced or modified
Short in pigtail/connector where wiring was repaired or replaced
Failed internal park switch inside the rear wiper motor assembly

Fault status

⚠️ Status

BCM reports rear wiper park sense input is shorted to ground; rear wiper park detection may be unavailable and the rear wiper may not operate or park correctly.

🟡 Repair difficulty: Medium

⏱️ Diagnostic time: 0.5-2.0 hours