Instruments - Inaccurate/Erratic Fuel Gauge Readings
SI B 16 03 05Fuel Supply Systems
September 2005
Technical Service
This Service Information bulletin supersedes S.I. B16 03 05 dated June 2005.
[NEW] designates changes to this revision
SUBJECT
Erratic Fuel Level Display
MODEL
[NEW] E65, E66 since start of production up to 9/2005
SITUATION
Customer may complain of the following intermittent conditions:
^ The fuel level indicator displays only 1/2 or 3/4 full although fuel tank is full.
^ The fuel level indicator displays an empty tank although there is a sufficient amount of fuel in the tank.
CAUSE
[NEW] One of the possible causes is an increased contact resistance at the fuel level resistor card or at the sending unit harness connector.
PROCEDURE
1. On a customer complaint basis only, interrogate the Instrument Cluster (Kombi) and DME fault memories.
2. In case of an erroneous signal/intermittent fuel sender failure, one of the following faults will be stored in both control modules:
Kombi - FC 37657 (9319 hex) - Level sensor 1; Signal or value above threshold, and/or
Kombi - FC 37658 (931A hex) - Level sensor 2; Signal or value above threshold.
DME - FC 10226 (27F2 hex) - Plausibility; fuel level, and/or
DME - FC 10781 (2A1D hex) Plausibility; fuel level, and/or
DME - FC 10782 (2A2D hex) Fuel level, signal.
[NEW] IMPORTANT NOTE:
With the previous DIS Diagnostics (CD D41/D42), it was not possible to correctly identify Kombi faults FC 37657/37658. You had to use DME fault memory to read-out fuel sender related fault codes. With DIS diagnostics CD D43.0 situation was corrected, and both KOMBI and DME fuel sender faults can be retrieved.
3. In case the DME fault memory DOES NOT store any fuel senders related fault codes, DO NOT replace fuel-sending units.
Note:
Make sure that customer is not confusing two different displays: fuel level and range shown at the same location in the cluster (range bar display will never reach the end the graph, even with the full fuel tank).
Important:
With the full fuel tank, the fuel gauge bar will never reach "full" (right end of the graph) position, if the average of the vehicle's fuel consumption is higher than 23 miles/gallon. Please explain this feature to the customer.
4. If the fuel sender related fault(s) are currently not present, and the fault frequency is less then 3 (two individual, intermittent occurrences), then DO NOT replace fuel sender units.
Clear DME and Instrument Cluster fault memories and release vehicle to the customer.
5. [NEW] If the fuel sender related fault(s) are currently not present, and the fault frequency is 3, or higher, then replace the affected fuel sender unit with the improved part (PN 16 11 6 759 833 right side, or PN 16 11 6 759 834 left side) and clear DME and Instrument Cluster fault memories. The optimized fuel sending units feature an increased spring tension between a resistor card and sensor contacts. The improved senders are recognized by the production date ("280705", or higher) stamped on top of the mounting flange (left unit), or inside the mounting arm (right sending unit).
6. If one of the fuel sender related faults is currently present in the DME memory, using Instrument Cluster Test Functions (Test 06: Fuel Tank and displayed values; and Test 17: Analog-Digital Converter), check the fuel senders operation. In the case of a fuel sender resistance exceeding 450 Ohm, replace the affected unit using an improved part.
Note:
Both tests 06 and 17 have to be "unlocked".
To enter Instrument Cluster Test Functions, press and hold trip odometer reset button and switch terminal R ON. Scroll to the test 19 (Unlock) by pressing on the trip reset button. To enter the test, press and hold on the reset button for more then 2 seconds. To unlock test functions, enter the total sum of the last 5 digits of VIN by pressing reset button the appropriate number of times. Then, exit Test 19 (press reset button for more then 2 seconds) and scroll back to Tests 06 and 17.
[NEW] PARTS INFORMATION
WARRANTY INFORMATION
Covered under the terms of the BMW New Vehicle Limited Warranty
For the appropriate labor operation and allowance refer to the KSD system.