Diagnostic Module Tank Leakage Pump - North AMERICAN Specification Vehicles Only
The Diagnostic Module Tank Leakage (DMTL) pump periodically checks the evaporative emission system and the fuel tank for leaks when the ignition is switched OFF.
The DMTL pump incorporates an electric air pump, a Positive Temperature Coefficient (PTC) heater element, a normally open changeover valve and a reference orifice. The DMTL pump is only operated when the ignition is switched OFF and is controlled by the Powertrain Control Module (PCM). The PCM also monitors operation of the electric air pump and the changeover valve for faults.
A connection with the PCM relay in the right Engine Junction Box (EJB) supplies startup battery power to the DMTL pump. The PCM applies separate ground connections to operate the heater element, the electric air pump and the changeover valve individually, as required.