landrover Workshop Repair Guides

Land Rover Workshop Service and Repair Manuals

Tank Leakage Detection (NAS Only)|Page 115 > < Tank Leakage Detection (NAS Only)|Page 113
Page 94
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FUEL DELIVERY SYSTEM – V8

DESCRIPTION AND OPERATION 19-2-11

Phase 2 - Leak Detection

Throttle plate
Air flow to engine
Purge valve
Charcoal canister
Fuel tank
Tank leakage detection module

Air intake
Air filter
Change over valve

10 Pump
11 Reference orifice

The ECM energizes the Change Over Valve allowing the pressurized air to enter the fuel system through the Charcoal 
Canister. The ECM monitors the current flow and compares it with the stored reference measurement over a duration 
of time.

Once the test is concluded, the ECM stops the pump motor and immediately de-energizes the change over valve. 
This allows the stored pressure to vent thorough the charcoal canister trapping hydrocarbon vapour and venting air 
to atmosphere through the filter.

M

M19 3580

0.5mm

1

3

2

4

5

6

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8

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10

11

Tank Leakage Detection (NAS Only)|Page 115 > < Tank Leakage Detection (NAS Only)|Page 113