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Tahoe / Yukon Service Manual

DTC P227B-P227E

Engine Controls and Fuel - 3.0L LM2 Diesel | Diagnostic Information and Procedures | Document ID: 5507639 Diagnostic Instructions Perform the Diagnostic System Check prior to using this diagnostic procedure: Diagnostic System Check - Vehicle Review the description of Strategy Based Diagnosis: Strategy Based Diagnosis An overview of each diagnostic category can be found here: Diagnostic Procedure Instructions DTC Descriptor DTC P227B Barometric Pressure Sensor 2 Performance DTC P227C Barometric Pressure Sensor 2 Circuit Low DTC P227D Barometric Pressure Sensor 2 Circuit High DTC P227E Barometric Pressure Sensor 2 Circuit Erratic Diagnostic Fault Information

Circuit Short to Ground Open/High Resistance Short to Voltage Signal Performanc
Ignition P0102, U060F, U1346* P0102, U060F, U1346* — U060F, U1346*
Serial Data U060F, U1319, U1346 U060F, U1319, U1346 U060F, U1319, U1346 U060F, U1319, U1346
Ground — P0102, U060F, U1346* — —
* Additional DTCs may set

Typical Scan Tool Data Barometric Pressure Sensor 2

Circuit Short to Ground Open Short to Voltage
Operating Conditions: Ignition = On & Engine = Off Parameter Normal Range: 56 to 105 kPa (8 to 15 PSI)
Ignition 255 kPa (37 PSI) 255 kPa (37 PSI) —
Serial Data © 2023 Gener 255 kPa (37 PSI) al Motors. All right 255 kPa (37 PSI) s reserved. 255 kPa (37 PSI)
Circuit Short to Ground Open Short to Voltage
Ground — 255 kPa (37 PSI) —

Circuit/System Description

Circuit Description
Ignition Supplied from a fuse.
Serial Data Digitally encoded information for communication between devices.
Ground Chassis Ground
Component Description
B75 Mass Airflow Sensor The assembly has several functions: The mass air flow sensor is a hot film type sensor that measures the mass of air (not the volume) entering the engine. The signal varies with engine load and is displayed by the scan tool in Hertz (Hz) and grams per second (g/s). The component houses the following sensors: – Barometric Pressure Sensor 2 – Intake Air Temperature Sensor – Intake Air Temperature Sensor 2 – Ambient Humidity
K20 Engine Control Module The control module contains a microprocessor used to process input data to control outputs. The control module controls a series of actuators to ensure optimal engine performance. The control module does this by reading values from a variety of sensors, interprets the data and adjusts the engine actuators accordingly.

Conditions for Running the DTC P227B DTC P0107, P0108, P14B6, P2228, P2229, P2610, U060F, U1346, U2011 = Not set DTC P0107, P0108, P14B6, P2228, P2229 = Not pending Engine = Not Running Ignition = On Time between current ignition cycle and the last time the engine was running = Greater than 10 s Frequency the DTC runs = Continuously — After the running conditions are met P227C, P227D, P227E Engine Running = For greater than 5 s Frequency the DTC runs = Continuously — After the running conditions are met Conditions for Setting the DTC P227B Condition 1 Barometric Pressure Sensor 2 ≠ 50 to 115 kPa (7 to 17 PSI) — For greater than 1 s Condition 2 The following parameters are not within 10 kPa (1.5 PSI) of each other: Barometric Pressure Sensor Barometric Pressure Sensor 2 Calculated Barometric Pressure The above condition(s) must occur for greater than 1 s. P227C Barometric Pressure Sensor 2 = Less than 50 kPa (7.25 PSI) — For greater than 4 s P227D Barometric Pressure Sensor 2 = Greater than 115 kPa (16.7 PSI) — For greater than 4 s P227E Barometric Pressure Sensor 2 = Signal noisy or erratic — For greater than 4 s Actions Taken When the DTC Sets DTCs listed in the DTC Descriptor category = Type B DTC Conditions for Clearing the DTC DTCs listed in the DTC Descriptor category = Type B DTC Reference Information Schematic Reference Engine Controls Schematics Connector End View Reference Master Electrical Component List 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 Control Module References Circuit/System Verification

  1. Ignition » On / Vehicle » In Service Mode
  2. Verify DTC  P227B, P227C, P227D, P227E, U060F, U1319, U1346 is not set. ⇒ If only DTC  P227B, P227C, P227D, P227E is set Replace the component: B75 Mass Airflow Sensor ⇒ If DTC U060F, U1319, U1349 is set and other DTCs are set Refer to: DTC P0102, P0103, U060F, or U1319 ⇓ If no DTC is set
  3. Verify the scan tool parameter: Barometric Pressure Sensor 2 = The value should not spike or drop out. Perform the action while monitoring the parameter: Wiggle the harness and connector: B75 Mass Airflow Sensor Wiggle the harness and connector: K20 Engine Control Module ⇒ If the value spikes or drops out Repair as necessary » Wiring / Terminal(s) / Electrical Connector(s) ⇓ If the value does not spike or drop out
  4. Operate the vehicle within the Conditions for Running the DTC. You may also operate the vehicle within the conditions that you observed from the Freeze Frame/Failure Records data. Verify the DTC does not set. ⇒ If the DTC sets Repeat step 2 ⇓ If the DTC is not set
  5. All OK. Repair Instructions Perform the Diagnostic Repair Verification after completing the repair: Diagnostic Repair Verification Mass Airflow Sensor with Intake Air Temperature Sensor Replacement — B75 Mass Airflow Sensor For control module replacement, programming, and setup refer to: Control Module References Additional Procedures Barometric Pressure Sensor Reset — Perform only when the following component/system is replaced or serviced: B75 Mass Airflow Sensor — Replaced K20 Engine Control Module — Replaced
  1. Ignition » On / Vehicle » In Service Mode
  2. Verify that all scan tool Event Data parameters under the following data list displays No: Exhaust Gas Recirculation System Malfunction Warning Event Data ⇒ If not the specified state Operate the vehicle within the Conditions for Running the DTC for the DTC identified by the Event Data parameter displaying Yes. ⇓ If the specified state
  3. All OK.