Instruments - Incorrect Fuel Level Readings
911 (996)1/04 2066
Binder -2, Fuel Exhaust, Engine Elec.
Incorrect Fuel Level Display In Instrument Cluster
Vehicle Type:
911 Carrera (996)
Model Year:
As of '02 (2)
Concerns:
After refueling, the fuel level display in the instrument cluster does not show a change in fuel level. To correct this the fuel pressure pipe in fuel tank needs to be rerouted.
Information:
If malfunctions of the fuel level display occur after refueling, or if the fuel level display does not show a change in fuel level after refueling, there is the possibility that the fuel level float sensor is blocked by the fuel pressure pipe in the fuel tank. On vehicles with this complaint, the routing of the fuel pressure pipe in the fuel tank must be altered as described in the following work procedure.
Parts Information:
Part Number Description
99951302140 Tie-wrap (2 ea. required per vehicle)
Tools:
Ratchet - 1/2" with extension
Socket a/f 13
Open-ended wrench a/f 10
Side cutters
Special Tool 3217
Warning!
Danger of fire and injury.
> Observe general safety regulations for work on the fuel system.
> Wear protective gloves and goggles.
Work Procedure:
1. Correct the routing of the fuel pressure pipe in fuel tank. "Figure 1, Item B" shows the excessive line bend in the pressure pipe which is blocking the fuel level sensor float.
"Figure 1, Item C" shows the corrected, correct routing of the pressure pipe. The tank does not have to be removed to correct the pressure pipe. The arrow (Figure 1, Item A) faces the direction of travel.
2. Open the front hood of the vehicle.
3. Remove battery:
- remove battery cover
- disconnect battery and pull off vent line
- remove battery holder
- lift out battery using the handles
4. Remove battery base plate (which is located over the fuel level sensor).
5. Since the seal will not be replaced, the position of the union nut to the fuel tank must be marked using a permanent marker pen. (Figure 2, item D).
5.1 Disconnect fuel line, vent line, and electrical plug connection from fuel sensor.
5.2 Press the release button on the plug-in coupling of the fuel or vent line and remove no line carefully. If necessary, collect escaping fuel with a suitable collecting container and shop towel.
5.3 Press release button on the plug housing and pull off toe plug of the electrical plug connection.
6. Release the union nut using special tool 3217, unscrew completely, and remove (Figure 3).
7. Remove fuel with suction:
If necessary, using a fuel extractor, completely remove the fuel through the fuel level sensor opening with suction. Only the fuel sensor needs to be raiser to do this.
Note:
Do not suck out the fuel through the filler neck, since this can damage the inner flap on the filler neck.
8. Raise the fuel level sensor until the electrical plug connection of the fuel pump is accessible on the fuel sensor. Unplug the plug of the electric lead for the fuel pump (Figure 4, Item E)
9. Release the electric lead for the fuel pump from the tabs (Figure 5, Item F).
10. Raise the fuel level sensor until the connections of the fuel lines are accessible on the fuel sensor.
10.1 Press the release buttons on the plug-in couplings (Figure 6, Item H) and pull off the fuel lines.
10.2 Completely remove the fuel sensor from the tank.
11. Remove fuel pump.
11.1 Put on a gasoline-resistant glove, hold the fuel pump fastened to tank flange, turn it counter-clockwise 15 (bayonet lock).
11.2 Take the fuel pump out of the fuel tank.
11.3 Tip the fuel pump to drain the residual fuel out of the pump housing into the fuel tank. The arrow (Figure 7, Item A) faces the direction of travel.
12. Correct the line routing of the pressure pipe:
Figure 8 shows the removed fuel pump with the excessive line bend of the pressure pipe (Figure 8, Item N, arrows). To correct this, the pressure pipe (Figure 8, Item N) must be routed parallel to the return line (Figure 8, Item i).
12.1 Mark the position of the tie-wraps (Figure 8, Item K) on the return line (Figure 8, Item j) with a permanent marker pen.
12.2 Carefully cut through the tie-wraps (Figure 8, item K) with side cutters and remove.
12.3 The pressure pipe must be routed parallel to the return line (Figure 9, Item i) The excess length of the pressure pipe is routed in the direction of the fuel pump to produce a larger line bend (Figure 9, Item N, arrows) on the fuel pump.
12.4 Hole the fuel lines in the installation position and fix them with two new tie-wraps (Figure 9, Item K) to the return ice at the locations of the permanent marker pen markings. Only pull the tie-wraps together tight enough so that they are securely seated without deforming the fuel lines. Cut off the protecting end of the tie-wraps with side cutters.
Note:
Only fuel-resistant tie-wraps Part No. 999 513 021 40) may be used.
13. Assembly
13.1 Place the fuel pump with the underside on the bayonet lock on the tank flange (only possible in one position) and turn approx. 150 to the right as far as it will go counter-clockwise.
13.2 Insert the fuel sensor into the opening of the tank so that the fuel lines as well as the electric lead of the fuel pump can be connected again to the fuel sensor.
13.3 Connect the fuel lines as well as the electric lead for the fuel pump. The connections for the fuel lines must audibly engage. Correct engagement of the fuel lines must be checked with a gentle pull.
13.4 Completely insert the fuel sensor and align so that the arrow mark (Figure 10, Item L) on the fuel sensor matches exactly with the first line marking - clockwise - (Figure 10, Item M) on the fuel tank. This will also increase the distance between float and fuel lines.
14. Tighten the union nut with the special tool "3217" up to the outset of the permanent marker pen mark (see Step 5). From this position, turn the union nut one rib further.
15. Installing the fuel line, vent line, and electrical plug connection.
15.1 Install fuel line and vent line. The connections must audibly engage. Correct engagement must be checked with a gentle pull on the plug connections.
15.2 Connect the electrical plug connection. Correct engagement must be checked with a gentle pull on the plug connection.
Work Procedure:
16. Install the battery base plate
17. Install the battery:
- insert battery install battery holder
- connect battery connect vent line
- install the battery cover
18. Close front hood
19. If necessary returned syphoned fuel back into the fuel tank.
20. Perform necessary steps work after disconnecting the battery. See 911 Carrera (990) Technical Manual, Group 9 Repairs: 91 - Work instruction after disconnecting the battery
Working Time:
Literature:
911 Carrera (996) Technical Manual, Group 9:
> Repairs: 9-1 - Work instructions after disconnecting the battery
Disclaimer