Diagnostic Monitoring of Tank Leakage (DMTL)

Diagnostic Monitoring Of Tank Leakage (DMTL)-NAS Only

Charcoal Canister with DMTL Pump (NAS only)





The DMTL system periodically checks the evaporative system and the fuel tank for leaks when the ignition is switched off. The DMTL pump is connected to the atmospheric vent of the charcoal cannister and incorporates a PTC (positive temperature coefficient) heating element a normally open valve and a reference orifice. The DMTL pump is only operate when the ignition is switched off and is controlled by the ECM (engine control module). The ECM (engine control module) also monitors the electric air pump operation and the normally open valve for faults. To check the fuel tank and EVAP system for leaks the ECM (engine control module) operates the DMTL pump and monitors the current draw. This is compared to a referenced figure established from the current draw when air is pumped through the reference orifice.