Please help to ID an 80A MIDI fuse 2006 GTI, -plus related info

[Marde]

Update about the GTI fuse that blew (SA2) for the power steering motor (V187):

My son and I are moving very slow on this GTI repair, maybe because the car is not supporting a normal mandatory car role, it is not needed to support life and a job. Despite our slow work, we want to get our GTI fixed ASAP.

The first SA2 Fuse problem (blown fuse) started during another problem with the Charging System; that thread is shown here. The summary of that first thread was the Alternator was removed and reinstalled but was not replaced. The 2-pin connector for the alternator was damaged and then replaced; details about that are shown in the link. We also installed (our first one) a new SA2 (80A) fuse. After we reassembled the car, the Alt (Charging System) was working normal, so we took it out for a test drive. Test drive was good. Before turning off the engine, I checked the battery with a DVM, and found the Alt was not charging the battery. I assumed the Alt was most likely failing ONLY during normal hot operating temperatures AND/OR that I should disconnect & clean most Charging System electrical connections to include the ground points.

About two days later, we cleaned most (not all) of the Charging System (large wires) connection points. None of the electrical contact points I cleaned had corrosion that was very concerning. The Phoenix AZ area is very kind to cars regarding rust, and electrical corrosion is easily maintained. Electrical corrosion DOES happen here, just not as bad as many other locations.

So, after this partial "electrical cleanup" we started the car and the Charging System is now working normal. The "Alt failure" from a couple days ago is now gone. I was about to take the car out for a test drive and found the power steering was dead; a stiff wheel. Crap. I then checked continuity of SA2 and it was electrically Open. Fuse blown; now a second time. It was late, so we wrapped it up for the night.

With the second fuse failure, this is now enough information to stop installing additional fuses, and most all DIY technicians should now troubleshoot, and find out why that fuse is blowing-up.

Because of the unique failure (mode and situation) of our SA2 fuse, I will install a second new fuse and plan for the best or the worst. If the 2nd new fuse blows, I will create a new thread about this.

If the fuse blows-up a third time; I already have lots of thoughts to share based on the VW repair manuals I recently downloaded from erWin. I will also start a new thread, for this subject based on the fuse failure AND our need for a new power steering motor. TBD.

The wiring circuit for fuse SA2 could not be more simple or basic. The wiring diagram suggests that fuse SA2 provides power ONLY to the motor. If SA2 is blowing, the fix is either (1) a new PS Motor or (2) a freak wiring "short" problem. It does not matter to me that this SA2 power is supplied to J500 - Power steering control unit; because it is only the V187 Motor that fuse SA2 is powering.

And now the bad news... If I need to replace the PS Motor, I might not be able to. This motor is part of an assembly called the PSCU (J500). The PSCU is an assembly that VW can replace, but they apparently do not replace "only the (V187) motor" -ever(?) The entire J500 assembly would be replaced by VW. However, in my mind, I could replace only the V187 motor and repair the J500 assembly.

And now more bad news... If I need to replace the PSCU, it is a major PITA process that includes removing the front subframe and the entire steering rack (with the attached J500 & V187).

And now the extra bad news... The 2006-2008 Gen1-Gen2 PSCU (aka the "Steering Gear") is apparently NO LONGER available. So, because of this, a new different part number (Steering Gear) J500 would be installed instead.

♦ The generation 2 steering gear is no longer available as a replacement
part.
♦ Install a generation 3 steering gear if replacing a steering gear.
♦ In addition to this, the electrical wiring set from the E-box to
the steering gear must be changed. It will be included with the
new steering gear. Refer to Parts Catalog.
♦ The electrical wiring set is delivered complete together with
the wiring for the service interval display.
♦ If the vehicle does not have a service interval display, then the
3-pin connector, not being used, must be sealed off with a Flat
Terminal Housing With Contact Seal - 1J0 973 803- . Refer to
the Parts Catalog.

This could NOT suck more, and only if I need a new PS Motor. TBD. I am planning to call the local VW Dealership to get a price quote -on Monday (8-24-2020) for a replacement PSCU (parts and labor) for our 2006 GTI.

GTI's? You still here? I would greatly appreciate a copy of your SSP 892403. PM me? Please?

-Marde

 

[GTI's]

Please keep in mind the WD are not always right, with that said everything I have seen about SA2 shows it as the J500 & V187 fuse. Unfortunately, the WD do no show all of the internal electronic inside the gray shaded module boxes just a few line which sometime you can see part of what is going on.

If you do need a new motor/module you should be able to swap out the module/motor with the same type used if you like going that route. Have you done a scan with a proper scan tool of the complete car and especially Address 44: Steering Assist to see what code/s it is giving. May be useful in deciding what to look at first.

Ps It seem your son just got this car and being an FSI one of the first things I would look at is the cam follower and intake cam lobe and Hpfp contact surface, seen to many people recently buy a used FSI and in short order post about failures of those parts. More than likely they had already failed and the PO just put a follower in it and passed it to the next person for repair. Plenty of DIY on how to check it out.

 

[Marde]

whoops... double post. Deleted.

 

[Marde]

Please keep in mind the WD are not always right, with that said everything I have seen about SA2 shows it as the J500 & V187 fuse. Unfortunately, the WD do no show all of the internal electronic inside the gray shaded module boxes just a few line which sometime you can see part of what is going on.

If you do need a new motor/module you should be able to swap out the module/motor with the same type used if you like going that route. Have you done a scan with a proper scan tool of the complete car and especially Address 44: Steering Assist to see what code/s it is giving. May be useful in deciding what to look at first.

Ps It seem your son just got this car and being an FSI one of the first things I would look at is the cam follower and intake cam lobe and Hpfp contact surface, seen to many people recently buy a used FSI and in short order post about failures of those parts. More than likely they had already failed and the PO just put a follower in it and passed it to the next person for repair. Plenty of DIY on how to check it out.

Good comments, thanks.
I did previously consider that; SA2 might also be powering everything inside the PSCM, and not only the motor. However, I assume that only the motor can draw HIGH amps, and enough to blow-up an 80-amp fuse. Bad assumption. Noted.

I will re-scan it, if and when SA2 is not blown. The resulting codes would not mean much to me, because my mind is too set, with fix whatever is causing that fuse to blow first. I will physically inspect the wire from the start-point(SA2) to the end-point (at PSCM) and verify it has NO splices & no damage; aka no other items are being powered by SA2. Also, I can not trust any codes until the charging system is rock solid.

Yes, -one of the first things we did, was install a new HPFP cam follower. (EDIT: No, we did nothing to verify the health of the cam lobe/s, other than peek inside at the shiny stuff inside -wink.) The PO provided us with good documentation, 5-years of service paperwork from two reputable shops. He was not a DIY'er. Timing belt and new AC within last 2 years, plus misc other.

EDIT-2: Until the Charging System is fully reliable & the SA2 fuse no longer blows-up & the car test drives OK while the engine is running at normal-hot temperature for 30 minutes (with our suspect charging system failures ONLY during heat), I do not need or want to use a scan tool.... However, when those three things happen together successfully, I will then trust a scan tool to help me learn what might also be defective, -and this might be my goal, -or my first goal.
-more inspections & wrenching is needed, and I will update this thread as our work progresses...
Cheers!

 

[Marde]

...I will physically inspect the wire from the start-point(SA2) to the end-point (at PSCM) and verify it has NO splices & no damage; aka no other items are being powered by SA2. Also, I can not trust any codes until the charging system is rock solid.
...-more inspections & wrenching is needed, and I will update this thread as our work progresses...
Cheers!

Update on this thread:
We were able to disconnect the PSCM wiring at Fuse SA2 and at the ground wire for this system at the battery area. After removing the battery & the battery tray, we unwrapped and inspected the hot & ground wires (for the PSCM) and found no damage. We could not follow the entire wiring down to the PSCM, because the car was not lifted-up on jacks; we did not get under the engine in order to follow these wires down to the end-point at the PSCM.

We finished our electrical "clean-up" while we had these PSCM wires in our hand. We cleaned the Hot and Ground points in the battery area, at the drivers side fender well area and/or behind the headlight. Plus, we added dielectric grease when we finished cleaning & then re-connecting these points.

The (big wires) electrical contact cleaning was done with great care, with hand tools and sand-paper. The only bad corrosion we found was minor, a white film, -similar to calcium or sulfate.

With some surprise, the Charging System is still working OK, and the SA2 Fuse has not yet failed (again). Knock on wood. We have now completed 4 test drives (in the past few days) and the car is running good or great.

We are about to celebrate this magical fix soon. TBD. Both problems might have been fixed by ONLY cleaning-up some/most electrical contact points!

We might also need to replace the valve cover gasket. TBD.

We are about to replace the spark plugs and maybe the coil packs too. TBD.

We will (scan tool) re-scan the car before the next round of maintenance. An air-bag problem is known to exist, and this will be addressed soon. The air-bag warning light mysteriously showed up about 4 or 5 (!!??) months ago, -but I just learned about this recently.

Cheers!