Volvo All Engines (2017 Emissions) Fault Code: P102112 PID: EMS Volvo Compression Brake (VCB) Control Circuit

The Engine Compression Brake Relay is supplied battery voltage through a fuse when the Engine Control Module (ECM) Relay is energized.
The Engine Control Module (ECM) grounds and completes the circuit for the Engine Compression Brake Relay to activate the compression brake.

Conditions for diagnostic trouble code (DTC):
1) Short circuit to battery voltage on A14.EB:30

Diagnostic operating conditions
1) Ignition key in ON position

Observable symptoms
1) Reduced engine braking since the compression brake cannot be activated
2) Reduced gear selection performance for some automatic transmissions

Probable cause
1) Connector
2) Short circuit in the compression brake solenoid valve
3) Wiring harness
4) Engine control module (ECM)