Code Definition

P1157 — Manifold Absolute Pressure sensor supply voltage fault

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

About P1157

P1157 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 P1157 is stored, the module has detected a sensor-related fault — the reported value from the named sensor is out of spec.

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.

P1157 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

The manifold absolute pressure sensor is powered by a regulated reference supply from the Engine Control Module (ECM), commonly 5V, which it uses to produce its pressure signal. DTC P1157 is stored when the ECM detects that the supply voltage to the manifold pressure sensor is outside the expected range, either too high or too low. Because this reference is frequently shared with other sensors, a supply fault can disturb several signals at once. Symptoms can include incorrect load calculation, poor running, reduced power, and an illuminated check engine lamp, sometimes with other sensor codes ...

Join TaT to view the complete code information and diagnostic details.

Quick Facts