E-TEC fuel reading screwed up

BogMonster · 22 May 2011, 20:42

Last time I was out I topped up the tank to full when I got back and reset the I-command setting to full (I use the EMM for the fuel remaining figure so when I refuel, I have to tell the EMM to reset the remaining fuel to a full tank).

Today I was out, and it was all screwed up. Fuel flow reading was good, and seemed consistent with what I have seen before, and the fuel economy reading was correct, but the reading for fuel remaining stayed at 149.9 litres (full tank) and on the other page, the trip fuel used and seasonal fuel used didn't move either.

The fuel remaining figure didn't flash (like it does when you first switch on the ignition, until it reads the fuel remaining from the E-TEC memory module) so no obvious problem except that the numbers didn't change!

I came back in after a couple of hours run (I knew I had full fuel so didn't worry) and shut everything off including the plotter, left it for a couple of minutes, then when I switched back on and started the engine again it starting deducting fuel off the fuel remaining reading. I went for a quick blast round the harbour, so it had used a couple of litres bringing the number down to 148L, then shut the ignition off. Key back on and it came back up with the "correct" reading of 148L (which by now was completely wrong as it forgot about all the fuel I used on the first run).

Any ideas what could cause this / whether it is likely to happen again? I've topped off the tank on the way home and reset to full tanks but I just wondered if anybody had any ideas what caused this? It was quite cold today (about 4 degrees above freezing I guess - coming into winter now so it's the coldest day I have used it so far) but other than that I didn't do anything different.

Chris · 22 May 2011, 22:00

Quote:

Originally Posted by BogMonster

Last time I was out I topped up the tank to full when I got back and reset the I-command setting to full (I use the EMM for the fuel remaining figure so when I refuel, I have to tell the EMM to reset the remaining fuel to a full tank).

Today I was out, and it was all screwed up. Fuel flow reading was good, and seemed consistent with what I have seen before, and the fuel economy reading was correct, but the reading for fuel remaining stayed at 149.9 litres (full tank) and on the other page, the trip fuel used and seasonal fuel used didn't move either.

The fuel remaining figure didn't flash (like it does when you first switch on the ignition, until it reads the fuel remaining from the E-TEC memory module) so no obvious problem except that the numbers didn't change!

I came back in after a couple of hours run (I knew I had full fuel so didn't worry) and shut everything off including the plotter, left it for a couple of minutes, then when I switched back on and started the engine again it starting deducting fuel off the fuel remaining reading. I went for a quick blast round the harbour, so it had used a couple of litres bringing the number down to 148L, then shut the ignition off. Key back on and it came back up with the "correct" reading of 148L (which by now was completely wrong as it forgot about all the fuel I used on the first run).

Any ideas what could cause this / whether it is likely to happen again? I've topped off the tank on the way home and reset to full tanks but I just wondered if anybody had any ideas what caused this? It was quite cold today (about 4 degrees above freezing I guess - coming into winter now so it's the coldest day I have used it so far) but other than that I didn't do anything different.

I had similar problems on a couple of occasions but put it down to a lose NMEA connector which intermitently gave me grief. Check all your connections and ensure no sign of corroded pins.

BogMonster · 23 May 2011, 01:22

OK, ta.

I figure it must be something to do with the memory module as the instant fuel readings worked fine at all times so I will try and figure out what that looks like and where it is hidden and see if there is anything green and furry in there.

Pikey Dave · 23 May 2011, 06:35

My first thought was "memory module", check the terminators as well.

Chris · 23 May 2011, 07:58

Quote:

Originally Posted by BogMonster

OK, ta.

I figure it must be something to do with the memory module as the instant fuel readings worked fine at all times so I will try and figure out what that looks like and where it is hidden and see if there is anything green and furry in there.

most likely culprit. It's a black stick about 4" long. with just one wire coming out. as opposed to the fuel tank converter which looks similar but has two wires.

It might of course have also been just one of those things that computers do occasionaly and if it happens again just reboot (switch off the engine and restart)

BogMonster · 23 May 2011, 23:54

Quote:

Originally Posted by Chris

most likely culprit. It's a black stick about 4" long. with just one wire coming out. as opposed to the fuel tank converter which looks similar but has two wires.

It might of course have also been just one of those things that computers do occasionaly and if it happens again just reboot (switch off the engine and restart)

OK ta, I'll break out the switch cleaner and have a look on the weekend

unfortunately I think the module is probably all bundled up in the harness so I will probably have to unscramble the whole thing to get at anything so not a 5 min job but I will have a look.

Reboot ... Windows on the water ... aaaargh

BogMonster · 22 June 2011, 22:45

Well I have used the boat a couple of times and the problem has never reoccurred so I don't know what to make of it.

Let sleeping dogs lie I think

Mollers · 23 June 2011, 08:53

Have a memory module plugged in now.

Only took 3 yrs.

Chris · 24 June 2011, 16:44

Quote:

Originally Posted by Mollers

Have a memory module plugged in now.

Only took 3 yrs.

Blimey, its been a while since you asked me for the details again.