Engine Controls - 6.6l (DTC p2228 to p2636) Chevrolet Cab & Chassis Silverado 3500

Circuit Description

The barometric pressure (BARO) sensor measures the pressure of the atmosphere. This pressure is affected by altitude and weather conditions. A diaphragm within the BARO sensor is displaced by the pressure changes that occur from varying altitudes and weather conditions. The sensor translates this action into electrical resistance. The BARO 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 BARO sensor provides a signal voltage to the ECM, relative to the pressure changes on the BARO sensor signal circuit. The ECM converts the signal voltage input to a pressure value.

Changes in BARO due to weather are relatively small, while changes due to altitude are significant. Pressure can range from 56 kPa at an altitude of 4 267 meters (14,000 feet), to 105 kPa at or below sea level. The BARO sensor has a range of 8-207 kPa. The ECM uses the BARO sensor input for fuel delivery and other diagnostics.

The ECM monitors the BARO sensor signal for pressure outside of the normal range. If the ECM detects a BARO sensor pressure that is excessively low, DTC P2228 sets.

DTC Descriptor

This diagnostic procedure supports the following DTC

DTC P2228 Barometric Pressure (BARO) Sensor Circuit Low Voltage

Conditions for Running the DTC

1. The engine run time is more than 1 second.
2. The ignition voltage is more than 7 volts.
3. DTC P2228 runs continuously once the above conditions are met.

Conditions for Setting the DTC

The BARO is less than 40 kPa for 10 seconds.

Action Taken When the DTC Sets

1. The control module illuminates the malfunction indicator lamp (MIL) on the second consecutive ignition cycle that the diagnostic runs and fails.
2. The control module records the operating conditions at the time the diagnostic fails. The first time the diagnostic fails, the control module stores this information in the Failure Records. If the diagnostic reports a failure on the second consecutive ignition cycle, the control module records the operating conditions at the time of the failure. The control module writes the operating conditions to the Freeze Frame and updates the Failure Records.

Conditions for Clearing the MIL/DTC

1. The control module turns OFF the malfunction indicator lamp (MIL) after 3 consecutive ignition cycles that the diagnostic runs and does not fail.
2. A current DTC, Last Test Failed, clears when the diagnostic runs and passes.
3. A history DTC clears after 40 consecutive warm-up cycles, if no failures are reported by this or any other emission related diagnostic.
4. Clear the MIL and the DTC with a scan tool.

DTC P2228

The barometric pressure (BARO) sensor measures the pressure of the atmosphere. This pressure is affected by altitude and weather conditions. A diaphragm within the BARO sensor is displaced by the pressure changes that occur from varying altitudes and weather conditions. The sensor translates this action into electrical resistance. The BARO 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 BARO sensor provides a signal voltage to the ECM, relative to the pressure changes on the BARO sensor signal circuit. The ECM converts the signal voltage input to a pressure value.

Changes in BARO due to weather are relatively small, while changes due to altitude are significant. Pressure can range from 56 kPa at an altitude of 4 267 meters (14,000 feet), to 105 kPa at or below sea level. The BARO sensor has a range of 8-207 kPa. The ECM uses the BARO sensor input for fuel delivery and other diagnostics.

The ECM monitors the BARO sensor signal for pressure outside of the normal range. If the ECM detects a BARO sensor pressure that is excessively high, DTC P2229 sets.

This diagnostic procedure supports the following DTC

DTC P2229 Barometric Pressure (BARO) Sensor Circuit High Voltage

1. The engine run time is more than 1 second.
2. DTC P2229 runs continuously once the above conditions are met.

The BARO is more than 110 kPa for 10 seconds.

1. The control module illuminates the malfunction indicator lamp (MIL) on the second consecutive ignition cycle that the diagnostic runs and fails.
2. The control module records the operating conditions at the time the diagnostic fails. The first time the diagnostic fails, the control module stores this information in the Failure Records. If the diagnostic reports a failure on the second consecutive ignition cycle, the control module records the operating conditions at the time of the failure. The control module writes the operating conditions to the Freeze Frame and updates the Failure Records.

1. The control module turns OFF the malfunction indicator lamp (MIL) after 3 consecutive ignition cycles that the diagnostic runs and does not fail.
2. A current DTC, Last Test Failed, clears when the diagnostic runs and passes.
3. A history DTC clears after 40 consecutive warm-up cycles, if no failures are reported by this or any other emission related diagnostic.
4. Clear the MIL and the DTC with a scan tool.

Test Description

The numbers below refer to the step numbers on the diagnostic table.

1. 4: A short to voltage on the 5-volt reference circuit will cause DTC P0653 to set.
2. 7: This step tests the signal circuit of the BARO sensor for a short to voltage. The short may backfeed through the sensor to the 5-volt reference circuit causing DTC P0653 to set.

DTC P2229

The position of the turbocharger vanes is controlled by the engine control module (ECM). The ECM utilizes a turbocharger vane control solenoid valve and a turbocharger vane position sensor to control the turbocharger vanes. When the engine is not under load, the turbocharger vanes are in an open position, or no boost condition. When the engine is under load, the ECM commands the control solenoid valve to close the turbocharger vanes, thus increasing the boost. The ECM will vary the boost dependent upon the load requirements of the engine. The vane position sensor uses the following 3 circuits

1. A 5-volt reference circuit
2. A low reference circuit
3. A signal circuit

The ECM provides the sensor with 5 volts on the 5-volt reference circuit and a ground on the low reference circuit. Movement of the sensor from the closed position to the open position provides the ECM with a signal voltage through the position sensor signal circuit. If the ECM detects that the commanded position does not meet the actual position, DTC P2563 will set.

This diagnostic procedure supports the following DTC

DTC P2563 Turbocharger Vane Control Position Sensor Performance

1. DTCs P0045, P2564, and P2565 are not set.
2. The ignition is ON.
3. The ECM is not commanding the turbocharger offset learn.
4. DTC P2563 runs continuously once the above conditions are met.

1. The ECM detects that the commanded vane position does not match the actual position.
2. The above condition exists for more than 12 seconds.

1. The control module illuminates the malfunction indicator lamp (MIL) on the second consecutive ignition cycle that the diagnostic runs and fails.
2. The control module records the operating conditions at the time the diagnostic fails. The first time the diagnostic fails, the control module stores this information in the Failure Records. If the diagnostic reports a failure on the second consecutive ignition cycle, the control module records the operating conditions at the time of the failure. The control module writes the operating conditions to the Freeze Frame and updates the Failure Records.

1. The control module turns OFF the malfunction indicator lamp (MIL) after 3 consecutive ignition cycles that the diagnostic runs and does not fail.
2. A current DTC, Last Test Failed, clears when the diagnostic runs and passes.
3. A history DTC clears after 40 consecutive warm-up cycles, if no failures are reported by this or any other emission related diagnostic.
4. Clear the MIL and the DTC with a scan tool.

Diagnostic Aids

1. If any service has been performed on the turbocharger or on the turbocharger components, a turbocharger relearn must be performed. Failure to perform the turbocharger learn procedure may cause this DTC to set. Refer to «Turbocharger Learn Procedure»(/chevrolet/cab-chassis-silverado-3500/2004-2007/remont/testing-diagnostics/#engine-controls-66l-introduction) .
2. An intermittent condition with the turbocharger vane control solenoid valve may cause this DTC to set. For an intermittent condition, refer to «Intermittent Conditions»(/chevrolet/cab-chassis-silverado-3500/2004-2007/remont/testing-diagnostics/#engine-controls-66l-troubleshooting-diagnosis__intermittent-conditions) .

DTC P2563

The position of the turbocharger vanes is controlled by the engine control module (ECM). The ECM utilizes a turbocharger vane control solenoid valve and a turbocharger vane position sensor to control the turbocharger vanes. When the engine is not under load, the turbocharger vanes are in an open position, or no boost condition. When the engine is under load, the ECM commands the control solenoid valve to close the turbocharger vanes, thus increasing the boost. The ECM will vary the boost dependent upon the load requirements of the engine. The vane position sensor uses the following three circuits

1. A 5-volt reference circuit
2. A low reference circuit
3. A signal circuit

The ECM provides the sensor with 5 volts on the 5-volt reference circuit and a ground on the low reference circuit. Movement of the sensor from the closed position to the open position provides the ECM with a signal voltage through the position sensor signal circuit. If the ECM detects an excessively low position sensor signal voltage, DTC P2564 will set.

This diagnostic procedure supports the following DTC

DTC P2564 Turbocharger Vane Control Position Sensor Circuit Low Voltage

1. The engine is running.
2. DTC P2564 runs continuously once the above conditions have been met.

1. The turbocharger vane position sensor voltage is less than 1 volt.
2. The above condition exists for more than 6 seconds.

1. The control module illuminates the malfunction indicator lamp (MIL) on the second consecutive ignition cycle that the diagnostic runs and fails.
2. The control module records the operating conditions at the time the diagnostic fails. The first time the diagnostic fails, the control module stores this information in the Failure Records. If the diagnostic reports a failure on the second consecutive ignition cycle, the control module records the operating conditions at the time of the failure. The control module writes the operating conditions to the Freeze Frame and updates the Failure Records.

1. The control module turns OFF the malfunction indicator lamp (MIL) after 3 consecutive ignition cycles that the diagnostic runs and does not fail.
2. A current DTC, Last Test Failed, clears when the diagnostic runs and passes.
3. A history DTC clears after 40 consecutive warm-up cycles, if no failures are reported by this or any other emission related diagnostic.
4. Clear the MIL and the DTC with a scan tool.

DTC P2564

The position of the turbocharger vanes is controlled by the engine control module (ECM). The ECM utilizes a turbocharger vane control solenoid valve and a turbocharger vane position sensor to control the turbocharger vanes. When the engine is not under load, the turbocharger vanes are in an open position, or no boost condition. When the engine is under load, the ECM commands the control solenoid valve to close the turbocharger vanes, thus increasing the boost. The ECM will vary the boost dependent upon the load requirements of the engine. The vane position sensor uses the following 3 circuits

1. A 5-volt reference circuit
2. A low reference circuit
3. A signal circuit

The ECM provides the sensor with 5 volts on the 5-volt reference circuit and a ground on the low reference circuit. Movement of the sensor from the closed position to the open position provides the ECM with a signal voltage through the position sensor signal circuit. If the ECM detects an excessively high position sensor signal voltage, DTC P2565 will set.

This diagnostic procedure supports the following DTC

DTC P2565 Turbocharger Vane Control Position Sensor Circuit High Voltage

1. The engine is running.
2. DTC P2565 runs continuously once the above conditions have been met.

1. The ECM detects that the turbocharger vane position sensor signal voltage is more than 3.9 volts.
2. The above condition exists for more than 6 seconds.

1. The control module illuminates the malfunction indicator lamp (MIL) on the second consecutive ignition cycle that the diagnostic runs and fails.
2. The control module records the operating conditions at the time the diagnostic fails. The first time the diagnostic fails, the control module stores this information in the Failure Records. If the diagnostic reports a failure on the second consecutive ignition cycle, the control module records the operating conditions at the time of the failure. The control module writes the operating conditions to the Freeze Frame and updates the Failure Records.

1. The control module turns OFF the malfunction indicator lamp (MIL) after 3 consecutive ignition cycles that the diagnostic runs and does not fail.
2. A current DTC, Last Test Failed, clears when the diagnostic runs and passes.
3. A history DTC clears after 40 consecutive warm-up cycles, if no failures are reported by this or any other emission related diagnostic.
4. Clear the MIL and the DTC with a scan tool.

DTC P2565

The fuel pump is located on the left frame rail between the fuel tanks. The engine control module (ECM) provides ignition positive voltage to the coil side of the fuel pump relay. The ECM energizes the fuel pump relay, which applies power to the fuel transfer pump. Fuel is transferred from the rear fuel tank to the front fuel tank in order to ensure all of the usable fuel volume is available to the engine. If the ECM commands the transfer fuel pump ON and a predetermined change in the front and rear fuel level sensors does not occur, this DTC sets.

This diagnostic procedure supports the following DTC

DTC P2636 Fuel Pump 2 Flow Insufficient

1. DTC P0500 is not set.
2. The engine is running.
3. The vehicle speed is 0 km/h (0 mph).
4. The primary fuel level is less than 25 liters (6.6 gallons).
5. The secondary fuel level is between 3-10 liters (0.8-2.6 gallons).
6. The above conditions are met for 20 seconds before the fuel transfer pump is commanded ON.
7. The fuel transfer pump is commanded ON for 120 seconds.

The ECM detects a primary fuel level increase and a secondary fuel level decrease of less than 2.6 liters (0.70 gallons) each, within 120 seconds.

1. The control module stores the DTC information into memory when the diagnostic runs and fails.
2. The malfunction indicator lamp (MIL) will not illuminate.
3. The control module records the operating conditions at the time the diagnostic fails. The control module stores this information in the Failure Records.
4. The driver information center, if equipped, may display a message.
5. The fuel gage will be commanded to empty.

Conditions for Clearing the DTC

1. A current DTC Last Test Failed clears when the diagnostic runs and passes.
2. A history DTC clears after 40 consecutive warm-up cycles, if no failures are reported by this or any other non-emission related diagnostic.
3. Clear the DTC with a scan tool.

1. When outside temperatures are below 0°C (32°F), the fuel tank pickup screen may ice over from water in the fuel tank.
2. If the engine is running while fueling the vehicle, this DTC may set.
3. The fuel will default to empty when this DTC sets.

The numbers below refer to the step numbers on the diagnostic table.

1. 3: This step determines if the condition is on the coil side or the switch side of the fuel pump relay.
2. 11: This step verifies the fuel transfer pump operation. If the test lamp flashes, the fuel transfer pump and circuits are OK.

DTC P2636

See also:
• Engine Controls Schematics
• Engine Control Module (ECM) Connector End Views
• Engine Controls Connector End Views
• DTC P0652
• Intermittent Conditions
• DTC P0653
• Turbocharger Cleaning and Inspection
• Turbocharger Replacement