1A | Fault code ( Readout on generic scan tool) | P2015 Purge system leaking, fault in function chain (P0440) P2013 Major leak in purge system (P0455) P2014 Minor leak in purge system, a minor leak (P0442) P2075 Minor leakage in purge system, micro leakage (P0442) |
1B | Engines 112, 113 as of 1/01 Fault code ( Readout on generic scan tool) | P2015-[2] Purge system leaking, fault in function chain (P0440) P2013-[2] Major leak in purge system (P0455) P2014-[2] Minor leak in purge system, a minor leak (P0442) P2075-[2] Minor leakage in purge system, micro leakage (P0442) |
2 | Fault storage Actuation CHECK ENGINE (MIL) malfunction indicator lamp | after expiry of test duration and fault following two successive driving cycles with faults |
3 | Checking frequency | once per driving cycle |
4 | Checked signal or status | change in speed of pressure values at the tank pressure sensor |
5 | Fault setting conditions Major leakage in purge system Minor leakage in purge system, Minor leakage 1 mm Minor leakage in purge system, micro leakage, 0.5 mm Checking duration |
Vacuum build-up of approx. 0.5 mbar per second is not achieved On a closed system the vacuum must not drop by more than 0.3 to 0,5 mbar per second (depending on the fuel level). On a closed system the vacuum must not drop by more than 0.1 to 0.15 mbar per second (depending on the fuel level). a maximum of 30 seconds for testing for major and minor leakages at least 50 seconds for checking for a micro leak |
6 | Check prerequisites | - Engine at idle speed - Vehicle stationary - Blocking time after starting the engine has lapsed (around 16 Minute) or mixture adaptation has been performed - Lambda control enabled - Intake air temperature less than +45°C - Coolant temperature at engine start lower than +100°C - Engine load less than 35% - Engine 112, 113: driving position D or R engaged - Air injection not active - Air pressure more than around 780 hPa (i.e. no test is performed above a height of around 2500 m) - - Low loading of activated charcoal canister - Fuel level in the fuel tank between approximately 1/4 and 3/4 - The tank pressure sensor will detect whether the fuel in the fuel tank is swilling around excessively (impermissible pressure leaps) and the checking procedure is aborted if this the case - No fault in the activated charcoal canister shutoff valve - No fault on fuel tank pressure sensor - No fault in purge control valve function (open/close) - Battery voltage higher than 11 V - No leak in pressure relief valve (ORVR) |
7 | | - The test for minor and micro leaks is aborted if an excessive lean correction of the lambda closed-loop control takes place during the vacuum buildup. - The function of the purge control valve is checked at the same time by the actuation. If the closed valve jams, the fault major leak is stored. - If no leakage for the fault major leak is found (there is a clear hissing noise if a leak of more than 3 mm exists), replace fuel tank pressure sensor. The fuel tank pressure sensor may have a fault which results in a signal which is constant but still plausible (sensor sticking). - The tests are not inhibited if there is an implausible fill level resulting from a faulty fuel gage sensor. |
P47.30-2037-76
Model 220 shown with engine 137
45 Filler neck with connection for on-board refueling vapor recovery (ORVR)
55/1 Fuel filter with integrated fuel pressure regulator
75 Fuel tank
77 Activated charcoal canister
82 Pressure relief valve (ORVR)
A1 Instrument cluster
A1e4 Fuel reserve indicator lamp
A1e26 "CHECK ENGINE" MIL
B4/3 Fuel tank pressure sensor
K40/5kT Fuel pump relay
M3 Fuel pump
N3/10 ME control unit
Y58/1 Purge control valve
Y58/4 Activated charcoal filter shutoff valve
A Air admission of activated charcoal canister
B Air admission to fuel tank and fuel pressure regulator
C Intake pipe vacuum
CAN Data bus
Any checks for leaks must be capable of detecting leaks from as small as 0.5 mm in the purge system. To do this a pressure test is carried out with the engine idling and with the vehicle stationary Testing takes place in three stages:
Test for major leaks
Test for a minor leak (equal to or greater than 1 mm)
Test for fine leak (equal to or greater than 0.5 mm).
Test for major leaks
The activated charcoal canister shutoff valve is closed and the purge control valve opened. The intake manifold vacuum flows to the fuel tank and a vacuum builds up in the fuel tank. This is detected by the fuel tank pressure sensor.
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If there is no vacuum build-up in the fuel tank
(approx. -6 mbar within approx. 12 seconds), there is a major leak present (e.g. fuel cap open, loose hose line). Diagnosis is aborted and the faults for function chain (P2015) and purge system major leak (P2013)are stored.
If the ME control unit detects a major system leak, the fuel reserve warning light in the instrument cluster or
"TRUNK OPEN! CHECK FILLER CAP" appears in the multifunction display.
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Test for a minor leak
The purge control valve is closed once a certain vacuum exists (approx. -6 mbar). The system is now likewise closed. The vacuum is them measured for approx. 30 seconds. It must not drop any faster than 0.3 to 0.5 mbar per second (depending on the level of fuel in the tank). If the vacuum drops more rapidly, there is a minor leak. Faults are stored for the function chain (P2015) and fine leak (P2014).
Test for micro leak (not engine 137.970)
If no minor leak has been detected, the purge system is briefly enabled and a vacuum of
approx. -6 mbar is built up again. If the system is closed, the vacuum must reduce not more rapidly than 0.1 to 0.15 mbar per second (depends on fuel level).
If the vacuum level falls faster than this, the faults are stored for the function chain (P2015) and very fine leak (P2075).
The reduction in the vacuum depends on the fill level in the fuel tank and on the degassing of the fuel. Degassing of the fuel is measured for a short time prior to the test and is allowed for in the fault statement. No test is conducted during the driving cycle if the fuel tank is filled to less than 1/4
The activated charcoal canister shutoff valve is reopened after the tests.