P1129 Cadillac Manifold Absolute Pressure Sensor Circuit Higher Than Expected

Possible causes

– Faulty Manifold Absolute Pressure Sensor
– Manifold Absolute Pressure Sensor harness is open or shorted
– Manifold Absolute Pressure Sensor circuit poor electrical connection

Symptoms

– Engine Light ON (or Service Engine Soon Warning Light)
– Engine hard to start
– Rough or erratic idle speed

P1129 Cadillac Description

The Manifold