Code Definition

P1906 — Charge air cooler pump relay circuit open or shorted to ground

System: Powertrain  |  Type: Manufacturer-Specific  |  Make: Volkswagen

About P1906

P1906 is a manufacturer-specific powertrain diagnostic trouble code recorded for Volkswagen vehicles. It belongs to the P-prefix family of codes, which covers engine, transmission, emissions, or fuel-system faults.

When P1906 is stored, the module has detected an open (broken or disconnected) electrical path in the monitored circuit; and a short-circuit (voltage pulled to ground or to supply) in the monitored circuit.

Scanning & clearing: A generic OBD-II scan tool will usually read and clear powertrain (P) codes. For live data, freeze-frame capture, and bi-directional tests you may need a more capable scan tool that supports the vehicle's ECM protocol.

P1906 is a manufacturer-specific code. The same code string on a different make may have a different meaning. Always confirm the code's definition against the vehicle's service information for the specific make and model under test.

Code Information

This fault code is triggered when the engine control module (ECM) detects an open circuit or a short-to-ground condition in the charge air cooler pump relay circuit. The charge air cooler pump circulates coolant through the intercooler to regulate intake air temperature. A malfunction in this circuit can lead to inadequate cooling, which may impact engine performance and efficiency.

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