Hi all.

I've got a KL Verada AWD, that's up until now been absolutely faultless. For the last few months the auto trans has been playing up a bit. I had a full service done on it and it lasted a short while but the problems returned.

When it's cold, it holds out on changing gears until it's at high revs. Normally the damned thing is in 5th by the time I'm doing 40kph, and is nearly always in too high a gear - that's how it's always been, but lately it's just changing late. When the box is warm, it's better but not perfect.

From time to time as well, it's like it's in neutral. I'll take off, and get to about 25-30kph, and it just does nothing, then it slips back in to gear and off she goes.

Since the problem started, I've had the orange engine image light appear on the dash, under decelleration and at idle. When I rev the engine it goes out. The manual says that if the engine light comes on, then there's a problem with the emissions control system. The way the auto is misbehaving sounds a bit like an engine vaccuum leak. I can't find any hoses that have split or come off though.

The auto works perfectly if I use manual mode (doesn't lag in shifts), and if I give it the boot in auto mode it shifts properly as well. It only misbehaves when I drive like a grandpa. Again, it sounds like a vaccuum thing, but do these auto's work using engine vaccuum, or is it all through the TPS & ECU?

Car has 154k km on it, and has done 125K of those mostly on LPG.

Any ideas? Thanks.

Other things can bring the Check Engine Light (CEL) to life besides the emissions system - particularly some other engine sensors (MAF/barometer/intake air temp, coolant temp to name some). That it is going away suggests that the problem is intermittent.

The transmission control has no dependence on vacuum as far as I know.

Even though the transmission has been serviced relatively recently, and you indicate that tippy shifts are okay, check the state of the ATF. If no auxiliary ATF cooler is fitted, AWD gearboxes can cook ATF relatively quickly (certainly well inside the nominal 45000km service interval).

The only things that I'm aware of significantly affecting the behaviour of shifts from the TCU point of view are:
- throttle position sensor (accelerator position sensor in TCL equipped cars)
- speed sensing

The L/W series have different speed sensing from the J series, and I'm not familiar with the details of the L/W setup.

Make sure you have genuine mitsubishi ATF in it.

Thanks for your assistance guys. I'll look in to it. I think I will have to get the thing looked at, though it's nearly time for an upgrade as she is getting a bit old now. Been a fantastic car.

Best place to start is with a proper scan of the ECU, the engine light can be related and may be something as simple as the TPS