Random cut-out, high idle, and code P1621

[highlander]

Just when I thought everything was going relatively well, the damn car has started playing up.

I was driving it out of town on Sunday night, and as I was going along a 50MPH road, I noticed the power drop off completely, the revs dropped momentarily, but power came back pretty much straight away. This happened a couple of times, and the car gave me the Engine Management Light. GREAT.

As I was on my way back into town about 20 minutes later, the same thing happened again, but I also got a message about the ABS/ESR system, and the ESP light started flashing.

When I got home, I used my cheapie eBay ODB2 code reader, and it gave me this:

P1621 - Control module Long term memory performance / Immobiliser code words do not match

Hmm. I cleared the code, and the EML went off, and it was running fine.

HOWEVER. This morning, I started the car up, and ran the engine for a while to clear the windscreen (totally fogged over). After the car had been running for a few minutes, it just cut out completely and died. I started it back up again, and it gave me the EML again. Code reader out, it gave me the same P1621 code. Nothing from the brakes this time though.

I drove the car, but as I was stopping at traffic lights, the damn thing cut out again.

I don't know whether this is related, but the car has been idling high recently - usually it idles around 750 - 800 RPM, but it's been idling much closer to 1500 RPM at times.

I don't have a multimeter, and wouldn't trust myself to touch one to a car battery if I did, but does this sound like the battery might be on its way out? Or is this more likely to be related to the high idle issue?

I did a Google search for Peugeot code P1621, and found this website:
http://www.pikit.co.uk/peugeotmt/psa%20 ... codes.html

Which gives this description:

Control module Long term memory performance / Immobiliser code words Not matched
MM6LP - System anomaly. Safety.

I'm imagining that MM6LP is the model of a particular Magneti Marelli ECU; might not be the one in my car though - not sure.

What should I try first? New battery? I don't know how old my battery is. Or should I just bite the bullet and take it in to a garage for some diagnostics?

[Doggy]

Graeme,

Is there anyone nearby with PP2000? It would probably give you a much clearer idea of where the problem lies.

[highlander]

I've never met anyone with it, unfortunately.

The members-with-PP2000 map on the Coupe Club forum says the nearest one is in Edinburgh, which is about 130 miles away.

[steve_earwig]

Duff battery connection? Voltage regulator spikes? Dunno, high idle wouldn't be that, maybe it's unrelated (where's Welly?) A brief Google says crank position sensor for the code, that's bugger all to do with the brakes though.

I don't have a multimeter

You can't really run an old car without one, 10 quid would buy you one that'll do anything you'd ever need.

and wouldn't trust myself to touch one to a car battery if I did

Seriously? I'll send my cat round to meow you through it

Mind you, if it's intermittent you might not actually see what's going on at the battery unless you catch it just right.

I reckon Doggy's right, you need some proper diagnostics.

[highlander]

and wouldn't trust myself to touch one to a car battery if I did

Seriously? I'll send my cat round to meow you through it

I have far too strong an aversion to being killed by electricity, probably as a result of previously nearly having been killed by electricity.

I also have this ingrained ability to f*ck things up worse than they already are. I wish I didn't, because I'd probably save myself a fortune.

I HATE intermittant faults. If something's going to break, it should damn well do it properly. And in such a way that it doesn't cost me a fortune to repair.

[Welly]

Random cutting can be the Crank Sensor, anything been done around the engine bay recently?

High idle, maybe the throttle position sensor? have a wiggle of the multi-pin plug (works on the Diesels).

You could buy the kit to diagnose further but if you don't like tinkering then save the money and shove it into a decent garage for a 'session'.

If you have a bad battery you'll likely get a fault message on the MFD whilst cranking; something like ELECTRONIC IMMOBILISER FAULT is favorite but it should not cause cutting out and high idle etc.

As you say, random faults are f*cking annoying but usually simple enough once located, hope you manage ok.

[steve_earwig]

I have far too strong an aversion to being killed by electricity, probably as a result of previously nearly having been killed by electricity.

I've lost count of the amount of shocks I've had, including earthing the mains through my body and being degaussed but I've never ended up in hostable (yet).12 volts-odd is not going to kill you, the only danger under the bonnet is the ignition as modern electronic ignitions put out a hell of a lot of volts.

[markw]

While that's true Steve, (about 12v not going to kill you), placing the probes of a multimeter across a battery while it set to measure current, might give you a little surprise!







(well, it'll surprise the multimeter at least....)

[steve_earwig]

Yeah, it'll go -pop- and you've wasted 10 quid. Easy to avoid though, just set to to 20 volts before you connect it.

[markw]

Of course.
Merely trying to point out that 12v with a lot of amps behind it still needs respect.

[steve_earwig]

It's not helping Highlander though, is it?

[markw]

I only mentioned it because Highlander said he wouldn't trust himself with one, that's all.

[highlander]

Correct, it's the amperage that makes me shy.

I wouldn't have a problem using a multimeter in a low-current setup, like I used to do when doing the electronics module in my high school physics class. I'm just nervous about touching metal electrodes to live battery terminals when I know the battery can produce a lot of amps.

In the absence of Peugeot Planet 2000 in the Aberdeen area, I think I'll ring round some garages and see if I can find one that does have it. Unfortunately it might need to be the Peugeot dealership - Arnold Clark ...

[steve_earwig]

The dealer's? I dread to think. Still, if you need to have the car then you can't really duck about

I only mentioned it because Highlander said he wouldn't trust himself with one, that's all.

Oh come on, you'd have to be some sort of chimpanzee to screw up measuring battery voltage with a meter, the worst thing you could do is connect the meter up on the amps scale as suggested, a cheapy meter will just stop working as it'll have burned tracks out on the circuit board. Or you could take one meter lead and connect it across the battery which will make the lead melt (and that's if you can find leads that you can even do that with any more). It doesn't even matter which way around you connect it up! (Unless you managed to find the last cheapy analogue meter in the world still for sale)

[PeterN]

I wouldn't worry overmuch about getting electric shocks, I was a TV engineer for 50 years and spent a lot of that time working on valve sets with really high voltages, shocks were common place, several a day was not unusual, you just picked up your screwdriver or whatever else you had involuntarily thrown across the room and got on with the job. The worst shock I had was not from a TV but a ham radio rig, 900 volts with quite a bit of current behind it, that did hurt.

There is not much on a car that will hurt you voltage wise except possibly the ignition source, that will make you jump, the real danger comes from the high current that the battery can supply which can turn metal objects red hot almost immediatly, including rings!. I'm 75 and my heart is pretty good - maybe it was all those shocks.

Peter