OBD-56
On-Board Diagnostics
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DTC P0046 Turbocharger Vane Control Position Performance (Figure OBD-18)
Figure OBD-18: Turbocharger Vane Control Position Circuit
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 control solenoid valve uses 2 circuits, a control circuit and a low reference circuit. The
ECM uses a pulse width modulation (PWM) on the control circuit to control the solenoid valve. The ECM provides a ground on the
low reference circuit. If the ECM detects that the commanded position of the turbocharger vanes does not match the actual posi-
tion, DTC P0046 will set.
Conditions for Setting the DTC
The ECM detects that the commanded position of the turbocharger vanes does not match the actual position for 1 second.
Action Taken When the DTC Sets
• The control module illuminates the malfunction indicator lamp (MIL) on the second consecutive ignition cycle that the diag-
nostic 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 consecu-
tive 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.