Sprinter 3500 EGR Backpressure Transducer Description
EGR Backpressure Transducer: Description and Operation
Description
DESCRIPTION
The EGR back pressure sensor is located in the exhaust stream next to the EGR bypass valve. The sensor determines the exhaust pressure before the
catalytic converter. The ECM uses the EGR back pressure sensor for engine protection and exhaust gas turbocharger protection.
To prevent damage to the turbocharger from overheating and/or overspeeding, the ECM monitors the exhaust pressure upstream of the turbocharger. At
high exhaust backpressures, the speed of the turbocharger drops and consequently the boost pressure drops. The ECM adjusts the guide vanes in the
turbocharger to regulate the boost pressure.
WARNING: If the exhaust backpressure is too high, the ECM switches to limp-in mode to protect the turbocharger. The limp-in mode can only
be reset by restarting the engine.
