This is a MAP sensor fault code, or a a vacuum leak in the induction system.
but before replacing any parts , you can run the below test to verify, my experience the map sensor is the issue but testing is needed to confirm
having a scan tool will be very helpful.
please let me know if you need anything else ,
2008 Chevy Truck Silverado 3500 4WD V8-6.6L DSL Turbo
DTC P0106 Diagnostic Instructions * Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure. See: Vehicle > Initial Inspection and Diagnostic Overview * Review Strategy Based Diagnosis for an overview of the diagnostic approach. * Diagnostic Procedure Instructions provides an overview of each diagnostic category. DTC Descriptor DTC P0106 - Manifold Absolute Pressure (MAP) Sensor Performance
Circuit/System Description The manifold absolute pressure (MAP) sensor measures the pressure inside the intake manifold. Pressure in the intake manifold is affected by turbocharger output, engine speed, accelerator pedal input, air temperature, and barometric pressure (BARO). A diaphragm within the MAP sensor is displaced by the pressure changes that occur from the varying load and operating conditions of the engine. The engine control module (ECM) supplies a regulated 5 volts to the sensor on the 5-volt reference circuit. The ECM supplies a ground on the low reference circuit. The MAP sensor provides a signal voltage to the ECM, relative to the pressure changes, on the MAP sensor signal circuit. The ECM converts the signal voltage input to a pressure value. Under normal operation, the lowest pressure that can exist in the intake manifold is equal to the BARO. This occurs when the vehicle is operating at idle or when the ignition is ON, while the engine is OFF. The ECM uses the MAP sensor to aid in diagnosis of the turbocharger performance. The highest manifold pressures occur when the turbocharger output is high. Manifold pressure can range from 58 kPa (8 psi) when pressure are low, to more than 240 kPa (34 psi) when pressures are high, depending on the BARO. The MAP sensor has a range of 43-255 kPa (6-36 psi). Conditions for Running the DTC * DTCs P0107, P0108, P2228, P2229 are not set. * The engine speed is less than 760 RPM. * The exhaust gas recirculation (EGR) valve is not commanded ON. * This DTC runs continuously when the above enabling conditions are met. Conditions for Setting the DTC The ECM detects that the BARO and MAP sensors disagree by greater than 14 kPa with the ignition ON, for greater than 10 seconds. Action Taken When the DTC Sets
* DTC P0106 is a Type A DTC. * DPF Regeneration is inhibited. * The ECM commands reduced engine power mode. * A message center or an indicator may display Reduced Engine Power. Conditions for Clearing the DTC DTC P0106 is a Type A DTC. Diagnostic Aids * A slight resistance of 20-30 ohms on the 5-volt reference or low reference circuits may cause this DTC to set. * Verify that any electrical aftermarket devices are properly connected and grounded. Refer to Checking Aftermarket Accessories. See: Vehicle > Component Tests and General Diagnostics Special Tools * J 23738-A Mityvac * J 35555 Metal Mityvac Circuit/System Verification
1. Verify that DTCs P0698 or P0699 are not set. ^ If any of the DTCs are set, refer to DTC P0698 or P0699. See: A L L Diagnostic Trouble Codes ( DTC ) > P Code Charts > P0698 2. Verify that restrictions do not exist in the exhaust system. Refer to Restricted Exhaust. See: Exhaust System > Symptom Related Diagnostic Procedures > Restricted Exhaust 3. Verify that the engine is in good mechanical condition before continuing with this diagnostic. Refer to Symptoms - Engine. See: Engine > Symptom Related Diagnostic Procedures > - Symptoms - Engine Mechanical 4. Ignition OFF for 90 seconds, determine the current vehicle testing altitude. 5. Ignition ON, observe the scan tool MAP Sensor parameters. Compare the parameter to the Altitude Versus Barometric Pressure. The BARO sensor pressure parameter should be within the specified range indicated in the table. 6. Ignition ON, observe the scan tool MAP and BARO parameters. The MAP and BARO sensor parameters should be within 14 kPa of each other. 7. Engine running, observe the scan tool MAP Sensor parameter. Slowly increase the engine speed to 2,000 RPM, then allow the engine speed to return to a stable idle. The MAP Sensor parameter should increment to a higher value at 2,000 RPM and then return to near BARO at idle speed. 8. Operate the vehicle within the Conditions for Running the DTC to verify that the DTC does not reset. You may also operate the vehicle within the conditions that you observed from the Freeze Frame/Failure Records data. Circuit/System Testing Important: You must perform the Circuit/System Verification before proceeding with the circuit/system testing. Important: You must perform the Repair Verification after completing the circuit/system testing. 1. Verify the integrity of the entire air induction system by inspecting for the following conditions: * Damaged components * Loose or improper installation * An air flow restriction or leak * Any snow or ice build-up in the air cleaner or MAF Sensor * Any ice, water, coking, or restrictions at the MAP Sensor Port 2. Ignition ON, engine OFF, observe the scan tool BARO parameter. Compare the BARO parameter to the range specified in the Altitude Vs. Barometric Pressure table. Refer to Altitude Versus Barometric Pressure. ^ If the BARO parameter is outside the range specified, replace the ECM.
2. Ignition ON, engine OFF, observe the scan tool BARO parameter. Compare the BARO parameter to the range specified in the Altitude Vs. Barometric Pressure table. Refer to Altitude Versus Barometric Pressure. ^ If the BARO parameter is outside the range specified, replace the ECM. 3. Ignition OFF, disconnect the harness connector at the MAP sensor. 4. Ignition OFF for 90 seconds, test for less than 5 ohms between the low reference circuit terminal A 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. 5. Ignition ON, test for the 4.8-5.2 volts between the 5-volt reference circuit terminal C 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. 6. Verify the scan tool MAP parameter is less than 45 kPa. ^ If greater than the specified range, test the signal circuit terminal B for a short to voltage. If the circuit tests normal, replace the ECM. 7. Install a 3A fused jumper wire between the signal circuit terminal B and the 5-volt reference circuit terminal C. Verify the scan tool MAP parameter is greater than 253 kPa. ^ If less than the specified range, test the signal circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the ECM. 8. If all circuits test normal, test or replace the MAP sensor. Component Testing Important: You must perform the Circuit/System Testing in order to verify the integrity of the MAF sensor circuits before proceeding with the Component Testing. 1. Ignition OFF, remove the MAP sensor. 2. Install a 3A fused jumper wire between the 5-volt reference terminal C and the corresponding terminal of the MAP sensor 3. Install a jumper wire between the low reference terminal A of the MAP sensor and ground. 4. Install a jumper wire at the signal terminal B of the MAP sensor. 5. Connect a DMM between the jumper wire from terminal B of the MAP sensor and ground. 6. Ignition ON, with the J 23738-A or J 35555, slowly apply vacuum to the sensor while observing the voltage on the DMM. The voltage should vary between 4.9-0.02 volts, without any spikes or dropouts. ^ If the voltage is erratic, replace the MAP sensor. Repair Instructions * Exhaust Particulate Filter Cleaning (LMM DPF Regeneration Enable) Exhaust Particulate Filter Cleaning (LMM DPF Service Regeneration) for DPF Regeneration Enable. * Manifold Absolute Pressure Sensor Replacement Repair Verification 1. Engine running, observe the scan tool MAP and BARO parameters. The MAP and BARO sensor parameters should be within 5 kPa of each other. 2. Engine running, command the turbocharger Vane Pos. Ctrl. Solenoid valve ON. With a scan tool, slowly increase the engine speed from idle to 2,000 RPM and then return the engine to idle speed. The MAP sensor parameter should increment to a higher value and then return to a near BARO value at idle. Notice: Refer to Diesel Particulate Filter (DPF) Regeneration Enable Notice. Certain engine control conditions can cause the exhaust particulate filter (EPF) to overload with soot. It will necessary to clean the EPF as instructed to remove the excess soot accumulation. To avoid the customer's return to the service department, perform the Exhaust Particulate Cleaning procedure. See: Continuous Trap Oxidizer, Diesel Emissions > Service and Repair