ABS/PSM warning lights

Hi wonder if anyone can shed some light on a slight problem , I've had my 996 Turbo remapped now as accelerating the abs / psm light comes on , if I turn the car off and restart no problem but again under hard acceleration it comes back on ?? Many thanks

Classic symptoms of a MAF sensor on the way out. However, assuming this started happening immediately after the remap, I would suggest getting a diagnostic check done to see if the MAF is giving the correct outputs, and to see if it has a fault code stored in the DME.

Keith its a normal occurrence in first and second gear after a remap, my understanding was that its the control systems struggling with controlling the extra wheel spin that's created. It should be just the odd flash or two nothing continuous.

I assumed you were getting the "PSM/ABS Failure" message in the OBC. If it is just the light flashing, that would indicate it is indeed wheelspin, but the light should not stay solid, and should go out of it's own accord without having to switch off the ignition.

Hi guys thanks for the feedback , the light is actually staying on until I turn off / on the ignition ?? ... It isn't storing anything in the fault codes either ??

Very odd. The reason that a dodgy MAF gives the PSM/ABS fault is because the DME and PSM modules talk to each other, and the DME sends signals which the PSM finds implausible. You don't get a CEL because RoW cars are not programmed to show the CEL with a faulty MAF. (US cars do throw the CEL, as they are programmed differently). I would see what the mappers have to say.

Hi I've already asked them but they can't seem to shed any light on it ..

Can you/they datalog the MAF output to see if the readings are correct? Or perhaps they could flash the original map back to the DME, and see if the problem goes away? If so, you will know if it is the map, or to look for something else.

Hi yes I could ask him to re flash it I guess , but to be fair it didn't have this problem prior to the map but its running lots more power and torque now . It's a tough call as I like the car with the BHP / Torque just not the lights coming on so it would be nice to find a solution

I meant just to test it - not as a permanent fix. My worry would be the cause of the PSM/ABS light. If the air:fuel ratio isn't right, it might be doing some damage. I won't ask who it is, but there are a lot of people around who have the ability to map these cars for big outputs, but very few who know how to do it properly and safely.

Putting car on a meter tomorrow to check AFR .. See what that says , will keep you informed , just thought someone on here may have experienced the same problem as I'm having , appreciate the replys

Have you retained the standard air filter? Mine has a tubi exhaust which registers 101 db on the noise test at Bedford, and I had real issues with frequent CEL, maf changes and at one point PASM/ABS warning. Some nurk had put a wire mesh filter in for a carrera with has a cut out where the C2/4 air box is shaped to clear the A/C pump. The plastic mesh protecting the delicate mesh in front of the MAF had detritus in it. Having tried a known good MAF in it, from my local indie, with no success, I had to invest in a new throttle body. I am not suggesting that you should jump straight to £670 worth of throttle body, and it would be a struggle to understand how a remap could have damaged the throttle body, so the reversion to std would be the first step in diagnosing the fault. If as Richard says the spurious fault goes away then you know that all is well with the MAF and the body. Re not storing fault codes; I found that if I disconnet the battery on mine, MY 2004, for about five minutes, the stored code are erased. Richard thinks this should't happen, but that is exactly what I did when I swapped the throttle body and on reconnection the CEL was extinguished and when I took it to my indie to read the codes, there were none to be read. I don't know if yours is a daily driver, and whether you do, but if yours it not a daily driver and you disconnect the battery between runs there is a likely hood that the fault codes will be lost, strange as it may seem.

Hi guys just to let you know I got to the bottom of this problem .... Don't ask me how or why but here goes , car had 7mm spacers on the front so I removed them and hey presto no more lights ... Weird I know but the lights have not come on since I removed them , I may have knocked a sensor or something when removing them but anyway they are off. Thanks for all replies

Like you say, weird. Maybe a loose connection, and the hard acceleration was the final straw? Anyway, glad to hear it is sorted, and not something more serious.

Thanks Richard