This code indicates a malfunction in the electrical circuit of the 'B' encoder contact plate inside the transfer case shift motor assembly. The encoder acts as a position sensor, telling the control module exactly where the transfer case shift mechanism is located. A failure means the system cannot accurately read the shift position, often disabling four-wheel drive.
The internal contact plate or encoder inside the shift motor assembly wears out, gets contaminated, or burns out, losing its ability to read the shift position.
Corroded, chafed, or broken wires and connectors at the transfer case shift motor interrupt the encoder signal.
An internal mechanical or electrical failure in the shift motor can cause the encoder to read out of range or fail to move the shift fork properly.
The control module itself may have an internal fault, though this is much less common than sensor or wiring failures.
The definition is universal; the diagnostics are engine-specific. Open your vehicle for the codes documented for it:
You can often drive the vehicle, but four-wheel drive may be completely disabled or stuck engaged. Driving with the transfer case stuck in 4WD on dry pavement can cause severe drivetrain binding and damage.
No, replacing the control module is almost never the fix for this code. It is almost always caused by a failed shift encoder/contact plate or damaged wiring, and replacing the computer will not resolve the underlying circuit fault.
It is a resistive contact strip inside the transfer case shift motor that acts like a position sensor, telling the control module the physical position of the transfer case shift fork.
On some vehicles, the encoder/contact plate can be replaced separately, while on others it is only available as part of the complete shift motor assembly. You must check the specific parts availability for your vehicle.