DTC Descriptors

DTC P1183: Supercharger Inlet Pressure (SCIP) Sensor Circuit Low Voltage

DTC P1184: Supercharger Inlet Pressure (SCIP) Sensor Circuit High Voltage

Diagnostic Fault Information

Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure.

Circuit	Short to Ground	High Resistance	Open	Short to Voltage	Signal Performance
5-Volt Reference	P0107, P0452, P0641, P1183	P0069	P1183	P0641, P2229, P2261	--
SCIP Sensor Signal	P1183	P0069	P1183	P1184	P1182
Low Reference	--	P0069, P1182	P1182, P1184	--	--

Typical Scan Tool Data

SC Inlet Pressure Sensor

Circuit	Short to Ground	Open	Short to Voltage
Operating Conditions: Ignition is ON. Normal SCIP Parameter: BARO -- Altitude Versus Barometric Pressure
5-Volt Reference	8-12 kPa	8-12 kPa	96-104 kPa
SCIP Sensor Signal	8-12 kPa	8-12 kPa	96-104 kPa
Low Reference	--	96-104 kPa	--

SC Inlet Pressure Sensor, Volts

Circuit	Short to Ground	Open	Short to Voltage
Parameter Normal Range: Engine Running 1.2-1.95 volts
5-Volt Reference	0.04 V	0.0 V	4.50-4.98 V
SCIP Sensor Signal	0.0 V	0.0 V	4.98 V
Low Reference	--	4.55-4.98 V	--

Circuit Description

The supercharger inlet absolute pressure (SCIP) sensor measures the pressure after the throttle body, but before the supercharger. Pressure in this area is affected by engine speed, throttle opening, air temperature, and barometric pressure (BARO). A diaphragm within the SCIP sensor is displaced by the pressure changes that occur from the varying load and operating conditions of the engine. The sensor translates this action into electrical resistance. The SCIP sensor wiring includes 3 circuits. The engine control module (ECM) supplies a regulated 5 volts to the sensor on a 5-volt reference circuit. The ECM supplies a ground on a low reference circuit. The SCIP sensor provides a signal voltage to the ECM, relative to the pressure changes, on the SCIP sensor signal circuit. The ECM converts the signal voltage input to a pressure value.

Under normal operation the highest pressure that can exist in the supercharge intake manifold is equal to BARO. This occurs when the vehicle is operated at wide-open throttle (WOT) or when the ignition is ON while the engine is OFF. The lowest manifold pressures occur when the vehicle is idling or decelerating. SCIP can range from 20-30 kPa, when pressures are low, to as much as BARO when pressures are high. The ECM monitors the SCIP sensor signal for pressure outside of the normal range.

Conditions for Running the DTC

P1183

P1184

Conditions for Setting the DTC

P1183

The ECM detects that the SCIP sensor voltage is less than 0.10 volt for more than 5 seconds.

P1184

The ECM detects that the SCIP sensor voltage is more than 4.80 volts for more than 5 seconds.

Action Taken When the DTC Sets

Conditions for Clearing the MIL/DTC

Reference Information

Schematic Reference

Engine Controls Schematics

Connector End View Reference

Electrical Information Reference

DTC Type Reference

Powertrain Diagnostic Trouble Code (DTC) Type Definitions

Scan Tool Reference

Special Tools Required

J 35555 Metal Mityvac

Circuit/System Verification

1. Verify the integrity of the SCIP sensor system by inspecting for the following conditions:

•	Any damage to the SCIP sensor housing

•	A loose or improperly installed SCIP sensor

•	A restriction in the vacuum source of the SCIP sensor

2. Ignition ON, observe the scan tool SC Inlet Pressure Sensor parameter. The reading should be BARO. Refer to Altitude Versus Barometric Pressure and decrease when the engine is running.

Circuit/System Testing

1. Ignition OFF, disconnect the harness connector at the SCIP sensor.
2. Ignition ON, allow sufficient time for the ECM to power down. Test for less than 2 ohms of resistance between the low reference circuit and ground.

⇒	If greater than the specified range, test the low reference circuit for an open/high resistance. If the circuit tests normal, replace the ECM.

3. Ignition ON, test for 4.8-5.2 volts between the 5-volt reference circuit and ground.

⇒	If less than the specified range, test the 5-volt reference circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the ECM.

⇒	If greater than the specified range, test the 5-volt reference circuit for a short to voltage. If the circuit tests normal, replace the ECM.

4. Verify the scan tool SC Inlet Pressure Sensor parameter is less than 20 kPa.

⇒	If the greater than the specified parameter, test the signal circuit for a short to voltage. If the circuit tests normal, replace the ECM.

5. Install a 3-amp fused jumper wire between the 5-volt reference circuit and the signal circuit. Verify the scan tool parameter is greater than 100 kPa.

⇒	If less than the specified parameter, test the signal circuit for a short to ground, open/high resistance. If the circuit tests normal, replace the ECM.

6. If all circuits test normal, test the SCIP sensor.

Component Testing

Important: You must perform the Circuit System Testing before proceeding with the Component Testing.

1. Turn ON the ignition with the engine OFF and remove the SCIP sensor.
2. Install a 3-amp fused jumper wire between the 5-volt reference terminal C of the sensor and 5-volt reference.
3. Install a jumper wire between the low reference terminal A of the sensor and ground.
4. Install a jumper wire at the signal terminal B of the sensor.
5. Connect a DMM between the jumper wire from terminal B of the sensor and ground.
6. Install the J 35555 to the sensor vacuum port. Slowly apply vacuum to the sensor while monitoring the voltage on the DMM. The voltage should vary between 4.9-0.04 volts, without any spikes or dropouts.

⇒	If the voltage is not within the specified range or is erratic, replace the SCIP sensor.

Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.