Porsche Enthusiasts Club Forum

Recently bought a Promax chip from a member and decided to install it yesterday everything went well until I tried to remove the motherboard (top one) I unlocked the pins at the ribbon cable end and pushed the two locking tabs at the DME harness end then pushed with extreme force on the board but it will not come out.

Any help as to whether I am missing something

Board appears loose as when I move the locking tabs at the socket it moves from side to side but will not come out.

DME is 944 618 124 02 Typ 944S-MW-02 Bosch Motronic 0 261 200 195

Image of the lock tabs at the DME harness socket end

Hi David I had the very same thing, prob be easyer 2 explain over phone, ur welcome 2 call
07525374985

R try and explain, on the back were the main cable fits, in the 3 rows of plug the top row can be push down, towards 2 lower 2 this relese it.

Thanks for that I will give it a go next weekend as I put the DME back in the car to use throught the week, I hope that works because I daren't use any more pressure or I will snap something.

I worked out the lug did something, and within reasonable force I couldn't seem 2 relese anything, I was pushing in pushing out, 4 about an hour, then I pushed the top row off the pins down.

If I recall I think you need to lift the back of the top board before pulling back out of the connector.

Rich

Yes I unclipped the top board by pushing apart the two circuit board posts at the ribbon cable end so the top board was free to move backwards but no joy, however I will try what t3rra suggests and see how that goes just have to take it out of the car again now.

The S2 is different to other 944 in that it has the locking tabs at the DME harness connector end, a point made by Promax in their instruction .pdf but obviously some boards get stuck I suppose.

Mine Is an S and that dme looks the same. I had the same problem, nothing in the pro max instructions

The instruction related to the S2 is only a small paragraph in the section detailing how to split the boards and is easily missed I did until afterwards. I found this web site with very clear instructions for doing the same job on a 911 but to me the DME looks identical to mine so this may help someone.
http://www.911chips.com/Chip%20InstallC2.htm

I had the same problem with fitting the chip to my S. I chickened out and went to see Promax who fitted it for me. It took two of them, one holding the clips inwards at the connector end, the second lifting the rear of the board and pulling.

Certainly had the effect I was looking for, much more flexible car through the rev range now.

Hi Mick, how would u describe the change? I felt like it brought the increase in power around around 3-3/5 instead off the 4 k. Iv also found that it's now taller in each gear by extra 10mph all do the power seems 2 start stoping off around 5.8/6k. I'm not sure how or y but 5th seems 2 be slower? Still 130mph in 4th not bad

Got my Promax chip fitted last night following a mixture of instructions it took less than an hour from start to finish.

Simplest method for the S2 (and probably any S model) was:
Disconnect the battery if your boot lock only operates the motor then leave the boot open or you will have to unlock it from inside the hatch to re-connect the battery as you can't open the hatch with the battery off.
Remove DME from car
Gently bend back the tabs on the case and remove
Ensure you are earthed or no static risk (don't do this standing on a manmade carpet)
Spilt the two boards by pushing the 2 posts apart at the ribbon cable end (hold the bottom and push with your thumbs so as not to push too far)
Gently bend the ribbon cables outwards (so they bow out from the board) opposite to how they are when you open the case.
This naturally raises the top board at an angle to the bottom
Push the two lock tabs either side of the DME harness connector (push them in towards the connectors) you may need to use a terminal screwdriver (thin) inserted then twisted so it stays in place in each side (so 2 drivers)
The top board should then just slide out, the top board includes the top set of DME connectors so push from the connector end do not prise it out by the board.
The chip (numbered 1267.......) is in the middle of the top board under a plastic clip which you have to gently prise off, do not remove the chip with similar identification on the bottom board.
Remove chip noting the end with a notch in usually the right hand side if you have the unit open with the boards split and the DME harness end away from you.
Fit new chip being careful not to bend the legs (make sure all the legs are in the socket before pushing it down, replace the clip on top of chip and re-assemble.

Not really had the chance to try it out properly but the car (1991 944S2 with KN panel filter) feels the same as before below 3000rpm but much smoother and stronger when accelerating above 3000rpm and comes on strong at 4000rpm. Also noticed top gear roll on feels much smoother and the car does appear to fly. Not sure I would have wanted to pay full price but for £55 well worth it.

Next job to remove the cat and fit a de-cat pipe or similar I think.

It seems to have spread the power band over a wider range - it now picks up from 3000-3500rpm, not sure about the top speed in each gear but I find it a much better match for my driving now. I'm pleased with it, I was also very pleased with Promax, free fitting from Andy and an offer of my money back if I didn't like it. I don't see that service too often.