Circuit Description
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 dependant upon the load requirements of the engine. The vane position sensor uses the following three circuits:
| • | A 5-volt reference circuit |
| • | A low reference circuit |
| • | 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.
DTC Descriptor
This diagnostic procedure supports the following DTC:
DTC P2564 Turbocharger Vane Control Position Sensor Circuit Low Voltage
Conditions for Running the DTC
| • | The engine is running. |
| • | DTC P2564 runs continuously once the above conditions have been met. |
Conditions for Setting the DTC
| • | The turbocharger vane position sensor voltage is less than 1 volt. |
| • | The above condition exists for more than 6 seconds. |
Action Taken When the DTC Sets
| • | The control module illuminates the malfunction indicator lamp (MIL) on the second consecutive ignition cycle that the diagnostic runs and fails. |
| • | 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
| • | The control module turns OFF the malfunction indicator lamp (MIL) after 3 consecutive ignition cycles that the diagnostic runs and does not fail. |
| • | A current DTC, Last Test Failed, clears when the diagnostic runs and passes. |
| • | A history DTC clears after 40 consecutive warm-up cycles, if no failures are reported by this or any other emission related diagnostic. |
| • | Clear the MIL and the DTC with a scan tool. |
Step | Action | Values | Yes | No |
|---|---|---|---|---|
Schematic Reference: Engine Controls Schematics Connector End View Reference: Engine Control Module Connector End Views or Engine Controls Connector End Views | ||||
1 | Did you perform the Diagnostic System Check - Vehicle? | -- | Go to Step 2 | |
2 |
Is DTC P0652 also set? | -- | Go to DTC P0652 | Go to Step 3 |
3 |
Is the TC vane position at or near the desired TC vane position while commanding the TC vane position sensor from 0-100 percent? | -- | Go to Step 4 | Go to Step 5 |
4 |
Did the DTC fail this ignition? | -- | Go to Step 5 | Go to Intermittent Conditions |
5 |
Is the voltage less than the specified value? | 4.8 V | Go to Step 7 | Go to Step 6 |
6 | Measure the voltage from the signal circuit to a good ground with a DMM. Is the voltage less than the specified value? | 4.8 V | Go to Step 8 | Go to Step 9 |
7 |
Did you find and correct the condition? | -- | Go to Step 13 | Go to Step 10 |
8 |
Did you find and correct the condition? | -- | Go to Step 13 | Go to Step 10 |
9 | Test for an intermittent and for a poor connection at the vane position sensor. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs . Did you find and correct the condition? | -- | Go to Step 13 | Go to Step 11 |
10 | Test for an intermittent and for a poor connection at the ECM. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs . Did you find and correct the condition? | -- | Go to Step 13 | Go to Step 12 |
11 | Replace the turbocharger vane position sensor. Refer to Turbocharger Vane Position Sensor Replacement . Did you complete the replacement? | -- | Go to Step 13 | -- |
12 | Replace the ECM. Refer to Control Module References for replacement, setup, and programming. Did you complete the replacement? | -- | Go to Step 13 | -- |
13 |
Did the DTC fail this ignition? | -- | Go to Step 2 | Go to Step 14 |
14 | Observe the Capture Info with a scan tool. Are there any DTCs that have not been diagnosed? | -- | System OK | |
