Start by checking the "Possible Causes" listed above. Visually inspect the related wiring harness and connectors. Check for damaged components and look for broken, bent, pushed out, or corroded connector's pins.
The cost to diagnose the P1056 Buick code is 1.0 hour of labor. The auto repair's diagnosis time and labor rates vary by location, vehicle's make and model, and even your engine type. Most auto repair shops charge between $75 and $150 per hour.
The reductant pump motor is controlled by the reductant control module. The Engine Control Module (ECM) sends a command to the reductant control module via a direct wire connection. This command is converted by the reductant control module into the desired pump speed The ECM checks the state of the wire to the reductant control module for circuit continuity. The signal sent by the ECM to the reductant control module is diagnosed for open circuit, short circuit to ground, and short circuit to voltage. The Diagnostic Trouble Code (DTC) will be set when the reductant control module detects that the reductant pump rotor is stalled for greater than 5 s.
Need more information on how to fix the P1056 Buick code? Get Access to Factory Service Manuals
Get the P1056 Buick code diagnosed by a professional: Find a repair shop in your area