Faulty electric/auxiliary transmission fluid pump motor control module; Damaged or corroded wiring harness or connector at the auxiliary pump; Blown fuse or faulty relay supplying power to the auxiliary pump circuit; Low or contaminated transmission fluid causing the pump to overwork and trigger a module fault; Internal short or open circuit in the auxiliary pump motor; Software glitch or outdated calibration in the transmission control module (TCM); Poor ground connection for the auxiliary pump motor control module

DTC codes / P0Bxx · Hybrid propulsion / P0B0D

P0B0DElectric/Auxiliary Transmission Fluid Pump Motor Control Module

P0B0D indicates that the electric or auxiliary transmission fluid pump motor control module has reported a fault condition to the powertrain control module (PCM). The PCM monitors the control module's communication and electrical circuits, and it sets this code when it detects an out-of-range signal or a failure within the module's internal diagnostics.

SystemPowertrain

Code typeGeneric (all makes)

SeverityMedium

Fix difficultyIntermediate

AreaHybrid propulsion

Symptoms you may notice

Illumination of the malfunction indicator lamp (MIL) on the dashboard
Often no symptoms besides the warning light, especially if the auxiliary pump is only used during auto start-stop events
Harsh or delayed shifting as the transmission may enter a fail-safe mode
Reduced fuel economy due to the engine remaining running instead of shutting off at stops
Overheating of the transmission fluid in prolonged stop-and-go traffic if the auxiliary pump fails to circulate fluid
A stored code P0B0D may be accompanied by other transmission control module (TCM) codes or a no-start condition in some vehicles

Common causes, most likely first

Faulty electric/auxiliary transmission fluid pump motor control module
Damaged or corroded wiring harness or connector at the auxiliary pump
Blown fuse or faulty relay supplying power to the auxiliary pump circuit
Low or contaminated transmission fluid causing the pump to overwork and trigger a module fault
Internal short or open circuit in the auxiliary pump motor
Software glitch or outdated calibration in the transmission control module (TCM)
Poor ground connection for the auxiliary pump motor control module

How to diagnose and fix it

Verify the code with a scan tool and check for any related TCM or PCM codes that may indicate a communication fault
Inspect the auxiliary pump wiring harness and connectors for chafing, corrosion, or loose pins, and repair as needed
Check the fuse and relay for the auxiliary transmission fluid pump circuit and replace if faulty
Measure resistance and voltage at the auxiliary pump motor control module connector to confirm power and ground integrity
Perform a visual inspection of the transmission fluid level and condition, and service if contaminated or low
If all electrical checks pass, reprogram the TCM with the latest calibration from the manufacturer
If the fault persists, replace the electric/auxiliary transmission fluid pump motor control module and clear the code

Before replacing the auxiliary pump module

A weak or failing battery can cause the auxiliary pump module to set this code because voltage drops during auto start-stop events disrupt the module's operation.
The auxiliary pump often runs only during engine stop events, so a failed pump may not be noticed until the vehicle enters a prolonged stop or the transmission begins to overheat.
Corrosion inside the connector at the pump module is a common cause that is frequently overlooked when only the module itself is replaced.
Some vehicles require a relearn or adaptation procedure after replacing the auxiliary pump module, and skipping this step can leave the code stored even with a new part.
This code can be set by a communication fault on the controller area network (CAN) bus, so check for other module communication codes before condemning the pump.

Can I keep driving with P0B0D?

You can usually drive the vehicle with this code, but avoid prolonged idling or stop-and-go traffic that relies on the auxiliary pump, and have the fault diagnosed soon to prevent transmission overheating or damage.

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.