Fuel/Emissions - MIL ON/DTC's P0446/P0455 Set
No: 19/01/05/NASFGN 310-00
Ref:
Issue: 1
Date: 28 September 2005
Fuel Filler Cap Dimensional Variation
AFFECTED VEHICLE RANGE:
Discovery Series II (LT) 3A807000 to 4A868629
SITUATION:
"SERVICE ENGINE SOON" WARNING LAMP ILLUMINATION
A customer may report a concern that the "Service Engine Soon" lamp is illuminated. Investigation may determine fault codes P0446, P0455 are stored, indicating a fuel vapor leakage. Very small dimensional variations between the fuel filler cap and the fuel filler neck can result in a minor vapor loss. The vapor loss is detected by the onboard diagnostic system (OBD) setting the fault codes and the lamp illumination.
RESOLUTION:
TEST FOR LEAK SOURCE AND REPAIR
Should a customer express concern regarding the above, refer to the Repair Procedure in this bulletin.
PARTS INFORMATION
DDW WARRANTY CLAIMS:
NOTE:
Repair procedures are under constant review, and therefore times are subject to change; those quoted here must be taken as guidance only. Always refer to DDW to obtain the latest repair time.
DDW requires the use of causal part numbers. Labor only claims must show the causal part number with a quantity of zero.
Normal warranty policy and procedures apply.
REPAIR PROCEDURE
TEST FOR LEAK SOURCE AND REPAIR
1. Remove the fuel filler cap and ensure the sealing surface is free from dirt/debris.
2. Install the cap and tighten the cap clockwise until you hear the fuel cap ratchet click at least three times.
3. Using T4, run a DMTL drive cycle test:
^ Follow the on-screen instructions and select "Diagnostic System".
^ Clear any fault codes.
^ Follow the on-screen instructions and select "Gasoline Engine".
^ Follow the on-screen instructions and select "Sub System Test".
^ Follow the on-screen instructions and select "Evaporative Leak" to carry out the DMTL test.
4. If no vapor loss is detected, no further action is required.
5. If vapor loss is still detected, renew the fuel filler cap.
6. Using T4, run the DMTL drive cycle test described in step 3 above.
7. If no vapor loss is detected, no further action is required.
NOTE:
Where renewal of the filler neck and fuel cap is necessary, return both the failed filler neck and cap as an assembly for inspection using the warranty returns procedure. The filler neck and cap set should be taped together to ensure they do not become separated.
8. If vapor loss is still detected, perform the following:
NOTE:
GTR lookup sequence is as follows:
GTR Home > NAS > Service Information/ LT Discovery Series II/2004 > Workshop Manuals > Discovery Series II Workshop Manual 1999 MY on > Bookmark "19-2 Fuel Delivery System V8" > Link "19.55.07 Filler tube - fuel"
9. Refer to the GTR Discovery Series II Workshop Manual Section 19.55.07 and replace the fuel filler neck assembly.
10. Verify that a new cap is properly tightened in the new filler neck
11. Perform the DMTL drive cycle test described in step 3 above using 4 to confirm that no vapor loss is detected.
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