How i change a fuel pump

Yeah, quit trying to play auto mechanic an take it to a qualified repair shop. You have no clue how it works.

Fuel Gage Inaccurate or Inoperative (Buick)

Turn the ignition switch to the RUN position.
Using a scan tool, inspect for Powertrain Control Module (PCM) diagnostic trouble codes (DTCs). Refer to Engine Controls in order to diagnose PCM DTCs.
Turn the ignition switch to the OFF position.
Disconnect the fuel tank unit connector.
Connect the 2 red leads from the J 33431-C to the harness connector terminal B and terminal D.
Turn the ignition switch to the RUN position.
Set the tester resistance dials to 40 ohms (EMPTY).
Set the tester resistance dials to 248 ohms (FULL).
Does the fuel gauge display E at 40 ohms and F at 248 ohms?


Fuel Gauge (Buick, Pontiac)
The magnetic fields of the 2 coils move the fuel gauge pointer. The coils are at right angles to each other. The 2 coils are connected to each other. The fuel level Pulse-Width Modulated (PWM) circuit from the PCM connects at a middle point. Battery voltage is applied to the end of the coil at the E end. Ground is applied at the other coil's F end.
The fuel level sender resistance is proportional to the fuel level. The voltage across the sender is the fuel level input signal that is applied to the PCM on CKT 30 and CKT 452. The PCM provides a Pulse-Width Modulated (PWM) fuel level output signal on CKT 455 (PPL/WHT) to the instrument cluster fuel gauge.
When the tank is low, the fuel level sender resistance is low. A larger current passes through the E coil in order to move the pointer toward E on the scale. When the tank is full, the sender resistance is high. More current flows through the F coil. This moves the pointer toward F on the scale.
With 2 coils operating the pointer, the gauge is not affected by changes in the vehicle's electrical system.

Replacing a fuel pump has nothing to do with instrument cluster lights or the clock staying on. Unless you shorted wires , did you disconnect the negative battery cable before hand ?
The body control module (BCM) performs the following functions:
• A/C compressor request
• A/C cooling fan
• Exterior and interior lighting control
- Daytime running lights (DRL)
- Automatic lighting control
- Fog lamps
- Interior lighting
• Battery rundown
• Chime
• Gauge control
• Instrument cluster indicator control
• Fuel gauge control
• Temperature gauge control
• Theft deterrent
Interpreting all of the driver warnings sent by the control modules on the class 2 serial data line
Sending the information to the instrument cluster in the form of a SPI serial data bus message
The following list of messages are sent by the BCM to the instrument cluster:
• Fuel gauge position
• Temperature gauge position
• Oil pressure
• Low engine coolant
• Check oil
• Volts
• ABS
• High beam
• Low fuel
• High temperature
• Washer fluid level low
• CRUISE
• BRAKE
• SERVICE VEHICLE SOON
• Door ajar
• Seat belt
• THEFT SYSTEM
• PRNDL
Check the fuel level sensor wires , the fuel level sensor is a input to the BCM .

you used voltmeter at the pump?> or just didnt here it run
do say this...please. details, matter....
it told you low fuel is it? is the fuel gauge near "E"
why not state that first.?
dead gauges, be 1st right, smacks of gross power loss.
right>? not clear to me what no gauges means.
but the voltmeter is #1 no?

did you tests fuse that look ok. fuse that look ok can be bad.
no gauges, means all dead, no movement,
well the fuel gauge must work , does it, does it match reality?
cranks but never runs. good input there.

does not run for the jeep 3 seconds.? (ASD rules)
no 12vdc power to pump, when cranking,?
01 grand WJ jeep usa.
is the skim lamp off, the cluster lamp for SKIM security is first.
it must go out after key turn on, or it will never run, ever.
I can help.
WJ jeep
this jeep has a voltage gauge, it must read 12v keyon
if not power is lost, or battery low.
if cranks that tells me the fues blew.
skim cuts spark and fuel, not cranking btw.
2002 cluster
http://jeepdied.com/cluster2002GC.JPG
see that lamp 12, if stuck on car will never start but will crank.
the lamp falses if skim is not working or stays on for ******* key.
we SCAN ALL CARS NOW.
IF You can not scan a modern jeep then it can near impossible to diagnose (a hard cold fact)
IF the ASD fails to work, the PCM tells you every time
all 8 ways for it to fail.
but that takes a scan tool (any modern scanner works,)

http://jeepdied.com/no-start.html

The fuel sending unit rod was bent during the instalation giving you the false readings. This is the thin metal rod that attaches the float to the sender.

Could be power fluctuations to the fuel gauge sending unit, a bad sending unit or a bad gauge. The sending unit would be the most likely cause.

Check you fuel pump relay. located on IPDM marked as ECM relay in the picture. Just change places of ECM RELAY and FOG LAMP relay and try to start. If it starts change the ECM relay. good luck

Gas gauge has nothing to do with fuel pump. possible causes:

1. Low fuel in tank, get some more fuel
2. Rat chewed the fuel gauge wire or its socket is loose
3. gauge itself is faulty

Sounds like float in fuel tank is sticking. Usually caused by using cheap gas. Fill it up and add a bottle of STP gas treatment. It might take more then one tankful w/STP to clean it completely. TIP: don't rely on the computer generated "mileage left" especially when that low on fuel, that is only an estimate. And also don't let it get that low on a regular basis because it will damage your fuel pump, fuel is used to cool electric pump in fuel tank and running it that low will shorten the life of your fuel pump.

it sounds like the sending unit is on the fritz.

Have your dealer check it out.

I hope this helps you out.

Thanks for letting FixYa.com ...fix ya


Terry

the fuel gauge and fuel pump is one assembly in the fuel tank. You will need to drop the fuel tank. May be a loose connection or faulty sending unit