98 Jetta Internal Control Module

Mileage: 126,000
My check engine light has been firing on and off for almost 2 years now. First it was the glow plugs, then the glow plug relay, and most recently the glow plug wire harness. With that recent job, an additional code fired reading (verbatim): 65535 U48023 Internal control module memory:checksum error
I was told that the product number is 028906021JB.

I kind of have absolutely no idea what this component does, but I was told that not until I start noticing my car running differently, would it be necessary to replace, unless I really didn't like staring at that red engine light. Now perhaps because of my gender the explanation went in one ear and out the other except the bit that said this part would cost $1500.

However, there is one thing my husband and I have noticed on two separate trips. Here in NC we have fast access from the middle of the state to the beach along 70mph interstates and bypasses. On the return trips, hence heading back to a slightly higher elevation, with cruise control set between 75 and 79, we both reported the car "losing power" on uphill stretches of the interstate. Efforts to override cruise control by stepping on the gas resulted in no change with the pedal pressed all the way to the floor.

Now could this be related at all to the Internal Control Module memory or is this another problem brewing? And can anyone enlighten me about this module and whether you've experienced something similar?

Thanks alot!

This part # is the computer (ECU) for the car. Ridiculous price isn't it?

Common problem with the Jettas. No biggie.

First things first. You need to replace the hose from the intercooler tube to the computer. Then, you need to replace the small piece of hose inside the ECU. There is an excellent chance that this will fix the problem. You do need to have the check engine light cleared.

Does the cruise disengage with the brake pedal? If so, you may have a bad clutch switch or it may have become disconnected. Cheap part.

I'll clarify a couple of things that may confuse.

(1)The check engine light has been cleared several times but comes back on immediately.

(2)When I said "Efforts to override cruise control", I really meant that cruise control was disengaged in an attempt to maintain or increase speed but efforts were fruitless as speed kept decelerating even with pedal depressed fully. And this was mainly experienced on slight prolonged inclines.

I'll clarify a couple of things that may confuse.

(1)The check engine light has been cleared several times but comes back on immediately.

(2)When I said "Efforts to override cruise control", I really meant that cruise control was disengaged in an attempt to maintain or increase speed but efforts were fruitless as speed kept decelerating even with pedal depressed fully. And this was mainly experienced on slight prolonged inclines.

Click to expand...

The check engine light will continue to return until you fix your boost leak. After replacing these hoses, see if your car has it's pep back. Then clear the CEL.

It is also possible that you have a problem with the N75 valve or one of it's hoses.

The cruise slowdown is consistent with a boost leak. Less boost = less power.

Let me give you several excellent links to follow to fix your car.

http://forums.tdiclub.com/showflat.php?C...rue#Post1002293

http://forums.tdiclub.com/showflat.php?C...o=7&fpart=1

The great and powerful paramedic is correct! Heed his wise words! Really I actually was going to post the same thing, but he being a better typist beat me to it. He is correct. Do this and problem solved! Good luck!