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For 1990-2009 cars only

DTC Descriptor

DTC P1182: Supercharger Inlet Pressure Sensor Performance

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

P1101

SCIAP Sensor Signal

P1183

P0069

P1183

P1184

P1101, P1182

Low Reference

--

P0069, P1182

P1182, P1184

--

P1101

Typical Scan Tool Data

SC Inlet Pressure Sensor

Circuit

Short to Ground

Open

Short to Voltage

Normal Range: BARO Ignition ON, engine OFF. Refer to Altitude Versus Barometric Pressure .

5-Volt Reference

8-12 kPa

8-12 kPa

96-104 kPa

SCIAP Sensor Signal

8-12 kPa

8-12 kPa

96-104 kPa

Low Reference

--

96-104 kPa

--

Circuit/System Description

Important: The following applies to the intake airflow system performance diagnostic that is used in this supercharged engine:

   • When referring to the supercharger intake manifold models, the plenum volume between the throttle body and the supercharger is considered to be the intake manifold.
   • When referring to engine pumping, the supercharger and the intercooler plenum are considered to be part of the engine.
   • The manifold absolute pressure (MAP) estimates are used in the engine air flow estimates. Air flow into the intake system must be the same as the air flow out of the intake system, the intake airflow rationality diagnostics (IFRD) calculates air flowing out of the engine based on MAP estimates, volumetric efficiency, and RPM.

The intake airflow system performance diagnostic provides the within-range rationality check for the mass air flow (MAF), supercharger inlet absolute pressure (SCIP), MAP, by-pass valve stuck, and the throttle position (TP) sensors. This is an explicit model-based diagnostic containing 4 separate models for the intake system.

    • The throttle model describes the flow through the throttle body and is used to estimate the MAF through the throttle body as a function of barometric pressure (BARO), throttle position, intake air temperature (IAT), and estimated SCIP. The information from this model is displayed on the scan tool as the MAF Performance Test parameter.
    • The first supercharger intake manifold model describes the pressure at the supercharger intake manifold and is used to estimate SCIP as a function of the MAF into the intake manifold from the throttle body and the MAF out of the intake manifold caused by engine pumping. The flow into the supercharger intake manifold from the throttle uses the MAF estimate calculated from the above throttle model. The information from this model is displayed on the scan tool as the MAP Performance Test 1 parameter.
    • The second supercharger intake manifold model is identical to the first supercharger intake manifold model except that the MAF sensor measurement is used instead of the throttle model estimate for the throttle air input. The information from this model is displayed on the scan tool as the MAP Performance Test 2 parameter.
    • A fourth model is created from the combination and additional calculations of the throttle model and the first supercharger intake manifold model. The information from this model is displayed on the scan tool as the TP Performance Test parameter.
    • In addition 5 new models have been added, these models run in the background.

The estimates of MAF, SCIP, and TP that are obtained from this system of models and calculations are then compared to the actual measured values from the MAF, SCIP, and the TP sensors and to each other to determine the appropriate DTC to fail. The following table illustrates the possible failure combinations and the resulting DTC or DTCs.

MAF Performance Test

MAP Performance Test 1

MAP Performance Test 2

TP Performance Test

DTCs Passed

DTCs Failed

X

X

OK

OK

P0101, P0121, P1101, P1182

None

OK

OK

Fault

OK

P0101, P0121, P1101, P1182

None

Fault

OK

Fault

OK

P0121, P1101, P1182

P0101

OK

Fault

Fault

OK

P0101, P0121, P1101

P1182

Fault

Fault

Fault

OK

P0121

P0101, P1101, P1182

X

X

OK

Fault

P0101, P1101, P1182

P0121

OK

OK

Fault

Fault

P0101, P0121, P1101, P1182

None

Fault

OK

Fault

Fault

P0101, P0121, P1182

P0101, P1101

X

Fault

Fault

Fault

P0101, P0121, P1182

P0101, P1101

Conditions for Running the DTC

    • DTCs P0120, P0121, P0220, P0506, P0507, P1183, P1184, P2135 are not set.
    • The engine speed is between 400-6,400 RPM.
    • The engine coolant temperature (ECT) is between 70-125°C (158-257°F).
    • The IAT is between -7 to +125°C (+19 to +257°F).
    • The change in the TP is less than 5 percent.
    • The above enabling criteria must be stable for more than 5 seconds.
    • DTC P1182 runs continuously when the above conditions are met.

Conditions for Setting the DTC

The ECM detects that the actual measured air pressure from the SCIP sensor is not within range of the calculated air pressure for the SCIP sensor that is derived from the system of models by more than 20 kPa for more than 0.5 second.

Action Taken When the DTC Sets

DTC P1182 is a Type B DTC.

Conditions for Clearing the MIL/DTC

DTC P1182 is a Type B DTC.

Diagnostic Aids

    • Any condition that can cause the MAF, MAP, SCIAP, and TP sensors to be shifted in value or any condition that may cause the by-pass valve to stick, at the same time may cause this DTC to set.
    • A slight to moderate resistance of 10-20 ohms on the 5-volt reference or low reference circuits may cause this DTC to set.
    • Any condition that may cause the supercharger by-pass valve to bind or stick in either the open or closed positions.

Caution: Refer to Road Test Caution in the Preface section.

    • Road test the vehicle and verify that the MAF sensor calculated g/s and the actual MAF g/s parameters are near or equal to each other.
    • A skewed MAF sensor, intake air flow restriction or intake air flow leak after the MAF sensor may cause the calculated g/s and MAF g/s parameters to disagree. Road test the vehicle while observing both parameters under various engine loads.
    • A wide open throttle (WOT) acceleration from a stop should cause the MAF sensor parameter on the scan tool to increase rapidly. This increase should be from 6-10 g/s at idle to 380 g/s or more at the time of the 2-3 shift.
    • A steady or intermittent high resistance of 15 ohms or more on the ignition 1 voltage circuit will cause the MAF sensor values to be skewed high by up to 60 g/s.
    • A skewed or stuck ECT or IAT sensor 1 will cause the calculated models to be inaccurate and may cause this DTC to run when it should not. Refer to Temperature Versus Resistance .

Reference Information

Schematic Reference

Engine Controls Schematics

Connector End View Reference

    •  Engine Controls Connector End Views
    •  Engine Control Module Connector End Views

Description and Operation

    •  Boost Control System Diagnosis
    •  Supercharger Description and Operation
    •  Boost Control System Description

Electrical Information Reference

    •  Circuit Testing
    •  Connector Repairs
    •  Testing for Intermittent Conditions and Poor Connections
    •  Wiring Repairs

DTC Type Reference

Powertrain Diagnostic Trouble Code (DTC) Type Definitions

Scan Tool Reference

    •  Scan Tool Data List
    •  Scan Tool Data Definitions
    •  Scan Tool Output Controls

Special Tools Required

J 35555 Metal Mityvac

Circuit/System Verification

  1. If DTCs P0101, P0102, P0103, P0106, P0107, P0108, P0121, P0641, P0651, P2228, P2229, or P2261 are set, refer to Diagnostic System Check - Vehicle for further information.
  2. Ignition OFF, verify the integrity of the entire supercharger air induction system, inspecting for the air induction system for the following conditions:
  3. • A restricted or collapsed air intake duct
    • A misaligned or damaged air intake duct
    • A dirty or deteriorating air filter element
    • A dirty or deteriorating air filter element
    • Any objects blocking the air inlet probe of the MAF/IAT sensor
    • Any contamination or debris on the sensing elements in the probe of the MAF/IAT sensor
    • Any water intrusion in the induction system
    • Any vacuum leak downstream of the MAF/IAT sensor
    • An intake manifold leak
    • A BARO sensor that is skewed or stuck
    • A skewed or stuck ECT or IAT sensor--Refer to Temperature Versus Resistance .
    • Any type of restriction in the exhaust system--Refer to Restricted Exhaust .
  4. Physically and visually, inspect the vacuum lines for cracking, loose fit, improper routing, or for blockage at the following locations:
  5. • The SCIAP sensor
    • The MAP sensor
    • The by-pass valve solenoid
    • The by-pass valve actuator
  6. inspect the by-pass valve and cable for any of the following conditions:
  7. • Sticking in either the open or closed position
    • Binding when opening or closing
    • Incorrectly adjusted cable
    • Any damage
         ⇒If any of the above conditions are found, refer to Supercharger Cleaning and Inspection .
  8. Ignition ON, observe the MAP and SC Inlet Pressure Sensor kPa parameters with a scan tool. Start the engine. The MAP and SC Inlet Pressure Sensor kPa parameters should decrease.
  9. If the MAP Sensor kPa parameter does not decrease, refer to DTC P0106 .
  10. Ignition ON, depress the accelerator pedal completely and observe the TP Indicated Angle parameter with a scan tool. The TP Indicated Angle parameter should read 98-100 percent.
  11. If the TP Indicated Angle parameter is not within the specified range, refer to DTC P1516, P2101, P2119, or P2176 .
  12. Ignition ON, perform a snapshot of the throttle actuator control (TAC) data while performing the following action. Refer to Scan Tool Snapshot Procedure .
  13. 7.1. Slowly depress the accelerator pedal to WOT position and then slowly release the pedal. Exit from the snapshot and review the data.
    7.2. Compare the TP Sensor 1 and the TP Sensor 2 parameters, frame by frame. The difference between the parameters should be less than 4 percent.
    If the TP Sensor 1 and Sensor 2 parameter difference is more than 4 percent, refer to DTC P0120, P0122, P0123, P0220, P0222, P0223, or P2135 .

Circuit/System Testing

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

Important: The harness connectors for the following sensors are of the same configuration but are not interchangeable. Review the engine controls schematics for the BARO sensor and for the SCIAP sensor and note the circuit colors. Inspect the wiring harness of the BARO sensor for the proper connections. Inspect the wiring harness of the SCIAP sensor for the proper connections.

  1. Ignition OFF, disconnect the harness connector at the SCIAP sensor.
  2. Ignition OFF, allow sufficient time for the control module to power down. Test for less than 5 ohms of resistance between the low reference circuit terminal A and ground.
  3. If greater than the specified range, test the low reference circuit for an open/high resistance. If the circuit tests normal, replace the ECM.
  4. Ignition ON, test for 4.8-5.2 volts between the SCIAP sensor 5-volt reference circuit terminal C and ground.
  5. 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.
  6. Verify the scan tool SC Inlet Pressure parameter is less than 20 kPa.
  7. If greater than the specified range, test the signal circuit for a short to voltage. If the circuit tests normal, replace the ECM.
  8. Install a 3A fused jumper wire between the 5-volt reference circuit terminal C and the signal circuit terminal B. Verify the scan tool parameter is greater than 100 kPa.
  9. If less than the specified range, test the signal circuit for a short to ground, open/high resistance. If the circuit tests normal, replace the ECM.
  10. If all circuits test normal, test or replace the SCIAP sensor.

Component Testing

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

  1. Ignition ON, remove the SCIAP sensor.
  2. Install a 3A fused jumper wire between the 5-volt reference terminal C of the sensor and a 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 SCIAP sensor.
  5. Connect a DMM between the jumper wire from terminal B of the SCIAP sensor and ground.
  6. Install the J 35555 to the SCIAP sensor vacuum port. Slowly apply vacuum to the sensor while monitoring the voltage on the DMM. The voltage should vary between 0-5.2 volts, without any spikes or dropouts.
If the voltage is not within the specified range or is erratic, replace the SCIAP sensor.

Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

    •  Supercharger Bypass Valve Actuator Replacement
    •  Charge Air Bypass Valve With Brackets Cable Replacement
    •  Charge Air Bypass Regulator Solenoid Valve Replacement
    •  Supercharger Air Inlet Pressure Sensor Replacement
    •  Control Module References for ECM replacement, setup, and programming