Honda Bmw 5 Service Manual

160 Fuel Tank and Fuel Pump 
General ........................... .I6 0.2 
Special tools ........................ .I6 0.2 
Fuel pump ......................... .I6 0.3 
Fuel tank  evaporative  control system ..... .I6 0.3 
Evaporative  system troubleshooting ..... .I6 0.4 
Warnings and cautions ................ .I6 0.5 
Fuel System Troubleshooting ...... .I6 0.6 
Fuel pump fuse and  relay .............. .I6 0.6 
Operating fuel pump  for tests ........... .I6 0.6 
Fuel pump electrical  circuit, testing...

This repair group covers service information specifically for the fuel supply  system. Information on the fuel injection  sys- 
tem  is covered  in 
130 Fuel Injection. 
In  the  descriptions  and procedures given below,  engine and 
engine management (DME) systems are referred to  by man- 
ufacturer  code. If necessary,  see 
100 Engine-General  for 
model year, engine code,  and DME applications. 
NOTE- 
Fuel  filter replacement is covered  in 020 Maintenance, 
Special tools 
Some of the procedures...

Fuel Tank and Fuel Pump 
Fuel pump 
The electric  fuel pump  is mounted  in the fuel tank  in tandem 
with  the right  side fuel level  sender.  The fuel pump delivers 
pressurized  fuel to the  fuel injection system. 
A pressure  regu- 
lator  maintains system pressure.  The quantity  of fuel supplied 
exceeds  demand,  so excess fuel returns to  the fuel  tank  via a 
return line.  See 
130 Fuel Injection  for more information. 
NOTE- 
Fuel pump  removal procedures  are given under Fuel  level 
sender...

Fuel Tank and Fuel Pump 
Evaporative system troubleshooting 
- Start by accessing  diagnostic trouble  codes (DTCs) using a 
BMW  or BMW compatible aftermarket scan  tool. 
For  purposes  of OBD 
II emissions compliance, the DME 
system sets a  diagnostic trouble  code (DTC) when it de- 
tects a leak that  is equal  or larger than minimum 
lealc 
sensed  by system. 
Malfunction Indicator Light (MIL) is illuminated  upon sec- 
ond recurrence  of fault.  See OBD  On-Board  Diagnostics. 
- When leak...

Fuel Tank and Fuel Pump 
Warnings and cautions 
Observe the following  warnings and cautions when servicing 
the  fuel  system. 
WARNING- 
* The fuel system  is designed  to retain  pressure  even when 
the  ignition  is off. When working with the  fuelsystem, loos- 
en  the  fuel  lines slowly  to allow  residual 
fuel pressure  to 
dissipate.  Avoid  spraying  fuel.  Use  shop rags to capture 
leaking  fuel. 
Before  beginning  any work  on the fuel system,  place a 
fire  extinguisher in the vicinity...

.-- - 
/ Fuel Tank and Fuel Pump - .. -. -- 1 
Fuel pump fuse and relay 
Troubleshooting  of any  fuel pump  fault should begin with 
checking  the fuel pump fuse  and the fuel pump  relay. The 
DME main relay should also be  checked. The fuel pump relay 
is located behind right side luggage compartment interior 
panel. 
I Fuel  pump relay 
BLU =blue ERN = blo$,m GRN =groan GRY = grsy ORG =orange PNI< =pink RED =red VIO =violel WHT = wlilte 
rk-; I I 1 ECM 
I I I 31 8 ,._--___.I 
NOTE- 
Special  tools...

- Fuel Tank and Fuel pump] 
Remove  fuel pump 
relay (arrow). 
4 Connect  relay socitet  terminal 6 (redlviolet  wire) to relay 
socket  terminal 
2 (whitelblue  wire) with a fused  jumper  wire. 
After  completing  tests, remove  jumper harness. 
CA 
UTIOG 
Relay  locations  may vary  Use care  when  identifying  relays 
and  making electrical  checks at 
the fuse/relay panel. See 
610 Electrical Component Locations  for additional  re- 
lay  information. 
The fuel  pump relay has  a 1.5 
md red/violet...

160-8 
I Fuel Tank and Fuel Pump 
4 Disconnect  harness connector  from tank sending  unit by 
sliding  connection  lock to  release connector. 
Connect  voltmeter  between fuel  pump terminals  on 
connector. 
NOTE- 
Fuel pump  power (+) is supplied  through the white/blue wire 
Ground 
(-) is  supplied  by the  brown  wire. 
With jumper  wire  connected in place of fuel pump  relay as 
described  above, check for battery voltage  at fuel pump 
harness  connector  terminals. 
If  voltage  and ground...

.- - 
Fuel Tank and Fuel purnpl 
Fuel pump power consumption, testing 
To achieve  accurate  test results,  the battery voltage  at the 
fuel pump connector  should be 
12.6 volts. Charge the  battery 
as necessary. 
A higher  than normal power  consumption may indicate a 
worn fuel pump, which  may cause intermittent fuel starvation 
due to  pump overheating  and seizure.  The only  remedy  is 
pump  replacement. 
A lower than normal power consumption 
may  indicate a blockage.  Be sure  to check that...

I Fuel Tank and Fuel Pump -- 
Fuel pressure gauge, installing 
(6-cylinder  models) 
4 Remove fuel  rail cover  by prying  off trim covers  (arrows) and 
removing nuts. 
4 If equipped,  remove schraeder valve  cap (arrow).  Blow fuel 
back  through  feed line using  a brief  burst  of compressed air 
(maximum 
3 bar  or 43.5 psi). 
WARNING - 
Fuel  in fuel  line is underpressure  (approx. 3 - 5 bar or 45 - 
75psi) andmay be expelled  underpressure. Do not smoke 
or  work  near heaters  or other fire...