What does it mean?
P1183 is a Powertrain (engine, transmission, fuel system) fault code. It indicates: Supercharger Inlet Pressure (SCIP) Sensor Circuit Low Voltage .
Symptoms
- Check engine light on, often as soon as the ignition is switched on
- Reduced power, boost limited or cut entirely
- Hesitation and flat spots during acceleration
- Rough idle and sometimes stalling
- Additional codes for other sensors if the shared reference has collapsed
- Higher fuel consumption
Likely causes
- Short to ground in the sensor signal wire, often where the harness rubs against the intake or a bracket
- Open 5 volt reference feed to the sensor, which collapses the signal
- Internal short or failure inside the pressure sensor
- Water or corrosion inside the sensor connector bridging the signal pin to ground
- Terminal damaged, bent or pushed back in the connector
- Damaged harness after work on the intake or supercharger
- Rarely, a failed module input circuit or a shorted sensor sharing the same reference
How to fix it
- Unplug the sensor and check for the 5 volt reference and a good ground at the harness connector with the ignition on
- If the reference is missing, look for a short on another sensor sharing that reference by unplugging them one at a time
- With the sensor unplugged, see whether the reported value jumps high; if it stays low, the signal wire is shorted to ground
- Measure resistance from the signal wire to chassis ground with both ends disconnected
- Inspect the connector for moisture, corrosion and pin damage; dry and reseal it
- Repair the shorted or open wiring and secure the harness
- Replace the pressure sensor if the circuit checks good, then clear codes and verify a plausible reading with the engine off