Engine Controls - MIL ON/DTC's P0171 or P0174 Set
No: LA303-007Issue: 1
Date: 21 Nov 2006
SECTION: 303-14 - ENGINE SYSTEM
Engine DTC P0171 or P0174
AFFECTED VEHICLE RANGE:
LR3 (LA) V8 Engine only VIN: 5A000360 to 6A413981
CONDITION SUMMARY:
IMPROVED SOFTWARE AVAILABLE TO RESOLVE P-CODES
Situation: A customer may report a concern that the malfunction indicator lamp (MIL)/check engine lamp is illuminated but does not report any vehicle driveablity issues.
An investigation using diagnostic equipment reveals Diagnostic Trouble Codes (DTCs) P0171 and/or P0174 - Fuel mixture too lean. The engine management system has detected that extra fuel is required to keep the system in specification.
In most cases, an air intake system leak after the mass air-flow (MAF) sensor will cause the above complaint. Any air intake system leaks should be diagnosed and rectified. Where no intake air leaks are present, a software calibration sensitivity issue can also cause the above complaint.
NOTE: This bulletin is not a diagnostic aid for air leaks, however, some common causes of air leaks which cause the DTC to be set are provided in the Repair Procedure.
Action: Should a customer express concern regarding the above and no intake air leaks are found, refer to the Service Procedure detailed in this bulletin to update the engine control module software.
PARTS:
No parts required for this bulletin. Information purposes only.
TOOLS:
IDS DVD 103 with Patch File 3 (or later) software installed
WARRANTY:
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
INSTALL LATEST ENGINE CONTROL MODULE TUNE
NOTE: This bulletin is not a diagnostic aid for air leaks, however, some common causes of air leaks which cause the DTC to be set are listed as follows:
Most common causes:
^ Engine oil dipstick is not fully seated and/or the 'O' ring is damaged.
^ Engine oil filler cap is not seated correctly.
^ Engine oil filler tube is not seated correctly and/or a seal is damaged.
^ Engine breather hose is not fully seated and/or the clips are not secured correctly.
^ Engine positive crankcase ventilation (PCV) valve is leaking at the cam cover.
^ Vacuum pipe is not correctly latched or secured.
Less Common Cause:
^ Intake manifold is not sealed correctly.
^ Exhaust gas recirculation (EGR) valve sleeve is preventing the intake manifold from seating correctly.
^ Acoustic pack under the intake manifold is preventing the intake manifold from seating correctly.
1. If IDS DVD 103 - Patch File 3 (or later) is being used, go to step 6.
NOTE: A software patch installation help file located on GTR provides instructions for the patch file installation process and could take up to six minutes to download depending on connection speed. For information on how to confirm that the patch file has been correctly installed onto IDS, refer to the applicable Patch Process Help File located in GTR.
Global Technical Reference (GTR) lookup sequence is as follows: GTR Home > NAS > Diagnostics/ LA - LR3/2005 > Patch Files > "Patch Process Help File" link
2. Logon to GTR from an internet connected PC and download the IDS software patch installation help file as follows:
^ Select 'Home' from the menu at the top of the main page.
^ From the menus on the left of the page, select 'Diagnostics' as the 'Information Type' and select the relevant model and model year.
^ From the 'All Information' results, select 'Patch Files'.
^ Click the file link 'Patch Process Help File'.
NOTE: This could take up to twenty minutes to download dependent on connection speed.
3. Using the help file as a guide, follow the instructions to download and save IDS DVD 103 - Patch File 3 (or later).
4. Install the software patch file into IDS.
5. Verify that IDS successfully restarts.
CAUTION: A Midtronics PSC-550 Vehicle Power Supply must be connected to the vehicle battery during diagnosis and module configuration. The diagnostic lead must be correctly secured to prevent accidental disconnection during the software update.
6. Connect the Midtronics PSC-550 power supply to the vehicle battery.
7. Connect the diagnostic equipment to the vehicle and begin an IDS session.
8. Note the current software levels of the Engine Control Module (ECM) as follows:
^ Follow the prompts to read the vehicle configuration.
^ When prompted "Do you wish to read diagnostic trouble codes?", select "NO" and then press 'tick' to continue.
^ When the "Content Model" is displayed, select the 'Vehicle Configuration' tab.
^ Select 'Module Information'.
^ Select 'Network integrity test'
^ Note the software part numbers displayed on the screen.
NOTE: During module configuration, the on-screen software part number information that IDS will display can be checked against the software part number noted in step 8 above. If the same software part number is displayed, the vehicle already has the desired software and the software download procedure can be discontinued.
9. Configure the ECM software as follows:
* Return to the 'Vehicle Configuration' tab and select 'Module Configuration'.
^ Follow the on-screen prompts.
^ Select 'Configure Existing Modules'.
^ From the sub-menu, select 'Engine Control Module'.
^ Click the tick-box to continue and follow the on-screen instructions.
^ Note the on-screen software part number information that IDS will display.
10. Compare the ECM software part number displayed on IDS to the software part number noted in step 8 above.
11. If the same software part number is displayed, terminate the software download.
12. If a different software part number is displayed, complete the software download to update the software.
13. Exit the IDS session and disconnect the diagnostic equipment from the vehicle.
Disclaimer