toyney83

iTrader: (3)

2005 uk sti fuel gauge not working. Occasinally works but majority of the time just reads empty, despite having a full tank. The fuel warning light comes on also even though the car will be full. Its started bringing the engine management light on reading low output voltage on fuel pump (not sure if its a safety to reduce consumption when light comes on). Anybody got any experience with this and is it an easy fix? Thanks

Athame1

iTrader: (2)

Yes, had the same thing on my05sti

https://www.scoobynet.com/scoobynet-...ing-light.html

Never got to the bottom of it as I recharged my battery after checking both sender in the fuel tank. And the fault went away. What's the condition of your battery?

Linked my thread as couple of useful pics

Let me know how you get on (as fault may be back on mine)

Hth

Mark

toyney83

iTrader: (3)

Hi, thanks for the response. I'm not sure to be honest. I'll have a check when I get home from work. How did you check your sender units? Cheers

Athame1

iTrader: (2)

hi

remove from petrol tank, then multi meter across senders check resistance changes when you move float up and down.

also clean all the connectors,check float for splits and arm moves freely.

toyney83

iTrader: (3)

Ok so I'm cracking on with testing the sender units today and I've got the main sender unit out. Tested resistance and I'm getting 1 ohms in the full position and 50 ohms in the empty. Is this normal and is there anything else I should be checking? Float moves freely and all connections are clean. Also which sender unit operates the gauge and level warning light? Thanks

Athame1

iTrader: (2)

ohms same as mine, which lead me to a fault in the Combination unit but still not sure where it is posted on other thread(to find location)

while I waited for response took battery off and recharged it and the fault went away (gauge was at half a tank all the time and low warning light on, sometimes go off ) and is still ok

check out post #19 on other thread (kind offer for more info)

I never got to the bottom of this post #19 was going to be my next move

hth

Don Clark

The combination meter is your dash panel (marked on wiring diagram posted)

Could be something to do with the fuel guage.......................

toyney83

iTrader: (3)

I've just been reading up on the sender units and it appears both units are linked. Didn't put a seconds thought in to it earlier but as I was pushed for time I never got chance to remove the sub sender. I did however remove the plug and test the resistance at the top of the unit. Can't remember off the top of my head but I'm sure the reading was up around 145 ohms. Shouldn't this be a similar figure to what I got on the main sender unit?

toyney83

iTrader: (3)

ok, scrap that last post. Sub sender is ok i think. got it out this morning and tested it. Reading 1.6 ohms at full position and 43 ohms at empty. all contacts are clean and float good and moving freely. Guess my next port of call is the combination meter. Anybody know what exactly i should be testing or looking for? Cheers

toyney83

iTrader: (3)

Just a little update incase theres ever anybody else with this problem and they stumble across this thread. So i got the combination meter out today and tested the fuel gauge. The readings i got here 163 ohms across ign and gnd, 33 ohms across ign and unit and 133 ohms across unit and gnd. All in all they seem pretty good and in spec acording to the Ken Gilbert sti w/shop manual i've been using. The next thing i think i have to test is resistance from sub sender to the combination meter. But as it stands the fault still isnt fixed. I'll try keep people updated and if anyone else has any info then im sure they'll be along soon enough

Athame1

iTrader: (2)

keep us updated