B1825 — Wiper Rear Park Sense Input Circuit Short To Ground

OBD2 code B1825 flags a problem with the body electrical system (wiper rear park sense input circuit short to ground). The car is usually drivable while you plan the repair. Common culprits: body control module (BCM) fault, faulty switch, motor or actuator of the affected system, corroded or loose connectors.

body electrical

Is it safe to drive?

Short-term driving is OK Usually safe to drive — body codes rarely affect drivability. Exceptions: exterior lighting and wipers in bad weather, and central locking faults that can leave the car unsecured.

How to diagnose with an OBD scanner

Read the code and freeze frame Connect an OBD2 scanner, confirm B1825 is stored, and save the freeze frame data — it shows engine conditions when the fault was detected.
Check for companion codes and TSBs Related codes often reveal the real root cause. Also check manufacturer technical service bulletins (TSB) for your make and model — many B0xxx issues have factory fixes or software updates. Search by VIN on the manufacturer site or nhtsa.gov.
Inspect wiring and connectors Visually inspect the wiring harness and connectors related to the body electrical system for damage, corrosion, chafing or poor contact.
Subsystem check Operate the affected function while watching its switch and motor PIDs in live data.
Subsystem check Inspect connectors and wiring at flex points (door jambs, tailgate hinges) — wires break there first.
Verify the repair Clear the code, complete a full drive cycle including the conditions from the freeze frame, and confirm B1825 does not return.

Approximate repair cost

Repair cost depends on which component actually failed. Typical scenarios for B1825 (parts and labor, USD, independent shop rates): Repair wiring or connectors: $80–$250; BCM repair or replacement: $300–$900; Replace the switch or actuator: $120–$450. Overall, fixing B1825 usually costs between $80 and $900. An accurate diagnosis before buying parts saves money — the most expensive scenario is rarely the first one to check.

Common questions

Will B1825 clear itself?

Sometimes B1825 clears after a few drive cycles if the fault was intermittent — for example a loose connector or a tank of bad fuel. The underlying cause usually remains, so the code tends to return. Clear it once; if it comes back, diagnose rather than erase it repeatedly.

What is the most common cause of B1825?

The most common causes are: body control module (BCM) fault, faulty switch, motor or actuator of the affected system, corroded or loose connectors.

What does OBD2 code B1825 mean?

How do I diagnose B1825 myself?

Start with a scan: confirm B1825, save the freeze frame and note any companion codes. Then inspect the wiring and connectors related to the body electrical system, and verify the suspect component against live data before buying parts.

How much does it cost to fix B1825?

Repair wiring or connectors — $80–$250; BCM repair or replacement — $300–$900; Replace the switch or actuator — $120–$450. Exact cost depends on the root cause, your vehicle and local labor rates — a proper diagnosis is the cheapest first step.

When your vehicle's engine control module detects an abnormal electrical condition in the rear wiper circuit, it records trouble code B1825. This specific code flags a short-to-ground fault in the rear wiper park sense input circuit. In practical terms, the Body Control Module (BCM) is seeing a signal that indicates unwanted contact between the wiper circuit and the vehicle's metal chassis. Because the BCM oversees multiple body electrical functions — including wipers, windows, door locks, and lighting — a short in one subsystem can sometimes cause strange behavior in others.

The rear wiper assembly includes a park position sensor that tells the BCM when the wiper blade has reached its resting position at the bottom of the rear windshield. When this sensor circuit develops a short to ground, the module receives a false signal indicating the wiper is either in the park position when it is not, or stuck in an unintended state. The ECU sets B1825 after confirming the fault across several drive cycles and stores a freeze frame snapshot — engine load, RPM, coolant temperature, and vehicle speed recorded at the moment the problem first appeared. Checking that snapshot before starting your diagnosis points you directly toward the conditions that triggered the fault, which often reveals whether the issue is environmental (water intrusion, road salt) or mechanical (worn harness, failed switch).

Once B1825 is active, the rear wiper typically behaves erratically. It may stop mid-stroke, fail to return to the park position, or refuse to operate entirely. In some cases the wiper works fine on manual activation but fails to auto-park when released. The check engine light may illuminate, though the MIL rarely appears for body codes alone — more often you spot the fault through a code reader or a persistent "wipe on" condition even with the stalk released. Other body functions like the rear defogger or tailgate release may intermittently glitch if the short affects a shared ground circuit.

Symptoms of B1825

Rear wiper fails to operate or stops mid-cycle
Wiper runs continuously without returning to the park position
Rear wiper works only in intermittent mode, not low or high speed
Check engine or warning light appears on the dashboard
Other body functions behave intermittently (tailgate release, rear defogger)
No effect on engine performance or drivability under normal conditions

Common Causes of B1825

The most frequent source of B1825 is damaged wiring in the rear hatch or liftgate area. Cables flex every time you open the tailgate, and insulation eventually cracks — especially in older vehicles or those exposed to moisture. Failed park sense switches inside the rear wiper motor assembly rank second, followed by corroded electrical connectors where water has infiltrated the seals. A blown fuse feeding the rear wiper circuit can also trigger this code, as can a defective Body Control Module in rare cases where internal circuitry shorts.

Damaged or chafed wiring near the rear wiper motor or hatch hinge
Failed rear wiper park sense switch or motor assembly
Corroded or loose electrical connectors in the rear wiper circuit
Blown fuse or failed relay supplying the wiper motor
Faulty ground connection for the rear wiper circuit
Water intrusion into the wiper motor housing or connector
Body Control Module internal failure (least common)

How to Diagnose B1825

Effective diagnosis follows a logical path from simple observations to targeted testing:

Connect an OBD2 scanner, retrieve code B1825, and record the freeze frame data. Note the RPM, load, coolant temperature, and speed values — these describe the conditions present when the fault was detected.
Inspect the rear wiper motor connector and harness visually. Look for cracked insulation, broken strands, corrosion, or pins that are bent or pushed out. Pay special attention to the flex point where the harness crosses the hatch hinge.
Check the fuse that powers the rear wiper circuit. Replace any blown fuse with the correct amperage rating and retest the wiper operation before proceeding further.
Examine the park sense circuit for continuity using a multimeter. With the connector unplugged, verify that the circuit does not show a direct short to ground — a reading near zero ohms confirms the short the BCM reported.
Operate the rear wiper while monitoring live data on your scanner or multimeter. Watch for voltage spikes or drops that indicate an intermittent short.
Clear the code and complete a full drive cycle that reproduces the freeze frame conditions. If B1825 returns, the fault is confirmed and you can proceed with repairs.

Repair Options with Pricing

Depending on which component is responsible for the short, repair costs vary significantly. Always address wiring and connector issues before replacing expensive modules.

Wiring repair or connector replacement: $80–$250
Rear wiper motor / park sense switch assembly replacement: $120–$450
Body Control Module repair or replacement: $300–$900

How Much Does It Cost to Fix B1825?

Most B1825 repairs fall between $80 and $900 depending on the root cause. The good news is that wiring damage and corroded connectors — the most common culprits — represent the least expensive fixes, typically running $80 to $250 for parts and labor. Replacing a failed rear wiper motor or park sense switch costs $120 to $450 in most cases. The BCM itself rarely fails, but if it does, parts and programming push the total to $300–$900. Always confirm the exact fault before replacing expensive control modules — an accurate diagnosis is worth more than the parts you will not need to buy.

Can You Drive with B1825?

B1825 carries a short severity rating, meaning it does not directly affect engine operation or transmission function. Your vehicle remains drivable, and the powertrain will operate normally. However, the rear wiper may not function correctly, which creates a safety concern in rain, snow, or darkness when rear visibility matters. If your rear wiper stops working entirely or runs continuously and distracts you, address the repair promptly. Until you can fix the fault, be aware of reduced rear visibility in inclement weather and check that the wiper blade position does not obstruct your line of sight.