Tmax Warning light

[MrGrumpy]

The 'Engine Trouble Warning Light' on my TMax mk3 has started coming on....not all the time, but comes on for a bit, then goes out for while, then comes back on - for no obvious reason. The engine seems to be running fine.
Then handbook says it comes on when a circuit monitoring the engine develops a fault - rather than the engine itself having a fault!

Anyone seen this themselves? Any idea whats going on?

[DougL]

Check that the battery isn't being overcharged. Get a multimeter and see if the voltage across the battery is less than 15 V. If above then your voltage regulator is toast. Not sure if this is the problem, but it could be. You can also check the diagnostics via the dash. I can email you the service manual if you'd like.

[Funkycowie]

or you can check out the diagnostics codes and download the service manual from the TMaxI Muppets forum on here

[Liam]

Is your speedometer working ok?

Could be a warning light to say the sensor is on its way out.

[MrGrumpy]

Is your speedometer working ok?

Could be a warning light to say the sensor is on its way out.

Everything is apparently working totally fine - although there was a peculiarity when I came back from Xmas when the battery had partially lost charge - it would turn but not enough volts to make it run. Recharged battery and it was fine. I do wonder if there is some small electrical problem giving odd problems.

Used to have speedo failures on older TMaxs!

[MrGrumpy]

or you can check out the diagnostics codes and download the service manual from the TMaxI Muppets forum on here

I've already got a service manual I downloaded a while back. Could be written in Icelandic for all the sense it makes to me! I think it says that if the light comes on, the fault code will be displayed on the clock when the engine is switched off - I'll have to try and look for that tomorrow.
However, the manual says the light might flash - presumably quite rapidly - or come on and stay on. But mine comes on for a bit and goes off again, which doesn't seem to be something envisaged by the designers!

Thanks all

[TmaX9]

It lights when the output from any sensors goes outside of tolerance, so can easily be influenced by under or over voltage in the system generally.
This can be either a battery developing a dead cell which totally 'confuses' the regulator, or the regulator itself is failing, and it could also be poor battery terminal connections or a bad earth on one of the main grounding points to the engine or frame.
These sort of problems don't always store an error code as they are inconsistent and a fault has to register for a while before it is stored in memory just to avoid over storage of minor glitches caused by human interference (tinkering with the electrics).

[MrGrumpy]

Latest news is that I've managed to get it to display an error code - 21 - Coolant temperature Sensor open or short circuit.
There is another big clue that the problem is in this area in that the water temperature gauge is now reading Maximum! This has only happened today - until now it has been reading normally. In addition, since Xmas, I've kept thinking that I can hear the cooling fan working as if the engine was getting warm, so it does look like the problem is in the water temp sensor.

How easy or hard this is to fix I've no idea - it is booked in for a service this week anyway.

[Funkycowie]

The Americans call it TMax fever.. hopefully its not that though as that requires a new fuel pump, can't think why right now.

Maybe thermostat?


EDIT: I remembered incorrectly, its not TMax fever...

[MrGrumpy]

The Americans call it TMax fever.. hopefully its not that though as that requires a new fuel pump, can't think why right now.

Maybe thermostat?


EDIT: I remembered incorrectly, its not TMax fever...

You're confusing me! Especially as I've just had a new fuel pump on the baby Burgman!!