wheel size BMW X5 2002 E53 M54 Engine Workshop Manual

18
M54engms43/STO36/6/00
123
DM-TL (DIAGNOSIS MODULE - TANK LEAKAGE)
FUNCTIONAL OVERVIEW:
The DM-TL is located in the drivers side rear wheel well in the X5 and next to the charcoal
canister on the E46 - M54.
1. In it’s inactive state, filtered fresh air enters the evaporative system through the sprung
open valve of the DM-TL.
2. When the DME activates the DM-TL for leak testing, it first activates only the pump
motor. This pumps air through a restrictor orifice (1.0 or 0.5 mm) which causes the elec-
tric motor to draw a specific amperage value. This value is equivalent to the size of the
restrictor.
3. The solenoid valve is then energized which seals the evap system and directs the pump
output to pressurize the evap system.
The evap system is detected as having a large leak if the amperage value is not realized, a
small leak if the same reference amperage is realized or no leak if the amperage value is
higher than the reference amperage.