Faulty Fuel Gauge

(but only when the speedo is working too).

Oh dear...........not another intermittent speedo

Have a look in the workshop manual, it tells you about trouble shooting the trip computer and the componants that feed data into it.

I thought I had.....see last para above

[BIG_MVS]

I'm having problems again now.

The fuel level flashes all the time and doesn't go down. I even went to the petrol station to fill up and it made no difference.

Any ideas?

The fuel level flashes all the time and doesn't go down.

Hi Martin,

There must be a Fuel Gauge virus going around at the moment .
If you are not winding me up!!!.....before you do anything else to it, what is the display reading while it is flashing? Note that figure, and do a full computer reset. Does the display reading change? The reset will stop the display from flashing.....go for a run, and note that if the display starts to flash the "Fuel remaining and Range" after two minutes, then it is the fuel gauge cct at fault, if, however, after 10mls the "Fuel remaining...Range...and MPG flashes, then, according to the manual, you have lost the consumption signal from the ECU.
It would be worth eliminating one or the other before you go any further

Hope this helps.

John

[BIG_MVS]

Yes did this yesterday and it stopped flashing and gave a "true" reading.

I then went for a drive and it started to flash again (just the fuel level) so it points to the fuel guage cct? what's a cct?

what's a cct?

Its an abbreaviation for circuit.....there are two ccts which will cause the display to flash...one is the fuel gauge cct.....the other is the fuel consumption cct

Yes did this yesterday and it stopped flashing and gave a "true" reading.

Can you remember what the reading was when it started to flash, and then after you reset the computer.
When you say (just the fuel level) was flashing, did not the range reading alongside flash also.......and in order to see if the MPG was flashing or not , you will have to get into the fuel comsumption mode by pushing the mode button, from memory, twice with the engin running. To me, it is worth doing that check.
Hope this is a bit clearer.

John

[BIG_MVS]

OK - Yesterday when I reset the computer the petrol warning light was on, reset and it went upto 2.5 Gals. Took it out and started to flash, filled up with £20 of 97 RON and the level stayed the same but it does decrease.

Now just been out to the garage and the Fuel Level and Range Flash. The MPG and MPH don't flash.

Over to you John, lead on McDougal.............

Martin,

and the level stayed the same but it does decrease.

Did you do a reset after filling up?...... and did you mean that it remained at 2.5, and started to count down as you drove home?

The MPG and MPH don't flash

Did you have the engin running when you did this check just now in the garage?

Sorry with all the questions, but it does help

[BIG_MVS]

Gordon Blue John, can't you just tell me which relay to wiggle?

I'll have another reset and drive tomorrow, any excuse to hear my new exhaust

I'll have another reset and drive tomorrow, any excuse to hear my new exhaust

Sorry to be a pain Martin, but it does eliminate either one of the cct`s. A point to remember when checking anything to do with the Fuel Gauge cct which involves disconnecting and reconnecting any connector, component, or battery, and when fault finding with the display indications, like we are doing at the moment..... the full reset procedure must always be done to be on the safe side, it only takes 15secs more than the normal reset, but worth taking the trouble
Also try and note if it starts flashing after two minutes, or 10mls.
Look foward to reading your results

John

LOL.....Lee, thats the easy option......I dont do easy options

[BIG_MVS]

OK. Reset from a flashing 2.2 GALs went to 5.5 Gals (which is what I would have thought was in the tank) and did not flash. Drove the car for around 5 mins and 4 miles and it started to flash. It is decreasing but flashing on range and level.

It is decreasing but flashing on range and level.

OK Martin,....But I find the above quote puzzling I am assuming that you checked the MPG with the mode button, and it was not flashing.
So, I think that the boot liner has to come out, and the Timer Relay must be checked.
The easiest way to do this is to detach the TSU, and get it into a position where you can get a meter on the connector where the wires go in.....Attach the Black lead of the meter to the Black wire in the TSU connector, (you must use this earth as opposed to the battery earth).....The Red meter lead to the YELLOW wire, then with batt connected and Ign off, you should get 0 volts....switch on Ign....Meter should read !2v......Switch off Ign, and the 12v should remain on the Yellow wire for a short period, mine stays on for 35secs, but it could vary, you should hear the Relay click when the volts drop away.
If all that checks out, disconnect batt, and replace the TSU with your spare (I remember you saying you had one)......do a full computer reset, go for a run and see what happens.
You will have to go for a run,... as you have already found out, as it takes time for the display to start flashing if it is still faulty.
I believe that the sensor is OK, as the gauge appears to read correctly though the display flashes, however it is a simple check.....detach the connector off the sensor and with the meter on OHMS across the sensor, you should get a reading of between 2 and 85ohms, but with your level of fuel I suspect it will be around 55 - 60ohms. Worth checking to be on the safe side. If all OK reconnect.
Let us know how you get on

John

[BIG_MVS]

Right. I'll have a look on Sunday and replace if needed with my spare. I found another one which I have sent to Mr Viola to try. You just know what's going to happen, he will fix his problem and I will have kept another faulty one as my spare Sod's Tony (Law)

[mettersl]

These TSU's seem to be pretty unreliable, has anyone investigated the insides to see what fails and if they can be repaired?

(BTW does the 610 have one??)
Lee