Blown fuse or faulty relay in the wiper motor circuit; Corroded, loose, or damaged wiring and connectors between the BCM and wiper motor; Failed front wiper motor assembly; Faulty wiper switch or multifunction stalk; Defective body control module (BCM) or wiper control module; Water intrusion into the wiper motor or connector causing corrosion

DTC codes / B09xx · Airbags, seats, doors, lights and comfort systems / B0900

B0900Wiper Motor Front Circuit

Q: What does code B0900 mean?

Wiper Motor Front Circuit. B0900 is a body code indicating that the front wiper motor circuit has a fault, such as an open, short, or abnormal voltage, as detected by the body control module (BCM) or wiper control module. The computer monitors the circuit and sets this code when the expected current or voltage does not match what the module commands.

B0900 is a body code indicating that the front wiper motor circuit has a fault, such as an open, short, or abnormal voltage, as detected by the body control module (BCM) or wiper control module. The computer monitors the circuit and sets this code when the expected current or voltage does not match what the module commands.

SystemBody

Code typeGeneric (all makes)

SeverityMedium

Fix difficultyIntermediate

AreaAirbags, seats, doors, lights and comfort systems

Symptoms you may notice

Front wipers do not operate at any speed setting
Wipers run only at one speed or fail to park correctly
Wipers may run continuously and not shut off
Intermittent wiper function is lost or erratic
Often no symptoms besides the warning light if the fault is intermittent

Common causes, most likely first

Blown fuse or faulty relay in the wiper motor circuit
Corroded, loose, or damaged wiring and connectors between the BCM and wiper motor
Failed front wiper motor assembly
Faulty wiper switch or multifunction stalk
Defective body control module (BCM) or wiper control module
Water intrusion into the wiper motor or connector causing corrosion

How to diagnose and fix it

Check the wiper motor fuse and relay, replacing any that are blown or suspect
Inspect the wiper motor connector and wiring for corrosion, chafing, or loose pins
Test for power and ground at the wiper motor connector while commanding wiper operation
Check the wiper switch signal to the BCM or wiper module using a scan tool
Perform a voltage drop test on the motor ground circuit to rule out high resistance
If all circuits test good, substitute a known-good wiper motor to confirm the fault
Clear the code and verify the repair by cycling the wipers through all modes

Wiper circuit faults that fool technicians

A wiper motor that runs but does not park can set B0900 because the park switch inside the motor is part of the monitored circuit.
Corrosion at the wiper motor connector from a clogged cowl drain is a frequent hidden cause that looks like a failed motor.
The BCM may set B0900 even when the wiper switch is at fault, because the switch input is part of the same circuit logic.
After replacing the wiper motor, some vehicles require a relearn or calibration of the park position through a scan tool.
Intermittent B0900 codes often trace to a chafed wire in the harness near the wiper pivot or hood hinge.

Can I keep driving with B0900?

You can usually drive the vehicle, but avoid driving in rain or snow because the front wipers may not work at all. If the wipers are stuck on, be aware they may drain the battery or scratch the windshield.

Tools that help

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Guidance is general and written for all OBD-II vehicles. Exact tests and values vary by model, so confirm the fault before replacing parts.