575M Shock Absorber ECUs

There have been many questions on the 575M shock ECUs caused by less than crystal clear descriptions in the parts catalogs. Here is my latest take including speculation two of the ECUs (there were 9 total) may have been part of HGTC retrofit kits sold by Ferrari.

Taz
Terry Phillips

Ferrari 575M Shock Absorber ECUs

At Assembly Number 52556, a new Steering Position Sensor was introduced on the 575M that required new Motronic ECUs, new wiring harnesses front and rear, and a new shock absorber ECU to use the signal provided by the steering sensor. Shock Absorber ECUs for 575Ms Assembly Number 52556 and later, including the HGTC shock ECU, will work on earlier cars but give a permanent suspension fault indication due to the missing steering sensor input.

Summary of Pre- Assembly No. 52556 Shock ECUs

Part Number 183960: What the Parts Catalog says:
-Valid till Ass. Nr. 47497 for RHD-
-Not as spare part-
-Replaced by 201673-
What we know: Fitted to early LHD and RHD cars, including those with FHP. Complaints in the British motoring press about sloppy handling led to its being sometimes retrofitted with 201673 on RHD cars and being fitted with 201673 at the factory until Ass. No. 47947 (SN 1308XX), after which it was replaced by 197211. On LHD cars, 183960 was replaced by 201673 at some point during production.

Part Number 197211: What the Parts Catalog says:
-Valid from Ass. Nr. 47498 for RHD-
-Not as spare part-
-Replaced by 201674-
What we know: Replacement for 183960 and 201673 at Ass. No. 47498 on RHD cars after complaints of soft handling with 183960.

Part Number 201673: What the Parts Catalog says:
-Valid till Ass. Nr. 47497 for RHD-
-Not as spare part-
-Replaced by 205618-
What we know: Used as a temporary replacement for 183960 on RHD cars until Ass.No. 47497, after which it was replaced by 197211. On LHD cars, replaced 183960 and was still being installed on all LHD cars, including FHP, until introduction of the Steering Position Sensor and new shock ECU at Ass. No. 52556.

Part Number 201674: What the Parts Catalog says:
-Valid from Ass. Nr. 47498 for RHD-
-Valid till stock exhaustion-
What we know: Form, fit, and function replacement for 197211 on RHD cars.

Part Number 205618: What the Parts Catalog says:
-Valid till Ass. Nr. 47497 for RHD-
-Valid till Ass. Nr. 52555-
What we know: Replacement for 201673. Never fitted at factory before introduction of the Steering Position Sensor and new ECU at Ass. No 52556. Possibly a retrofit for the HGTC kits for early cars.

Part Number 205619: What the Parts Catalog says:
-Valid from Ass. Nr. 47498 for RHD-
-Valid after stock exhaustion of 201674
-Valid till Ass. Nr. 52555-
What we know: Replacement for 201674. Likely never fitted at the factory. Possibly a retrofit for the HGTC kits for later cars.

Note 1: There is no apparent difference in function between RHD and LHD Shock Absorber ECUs and no apparent logic for why separate ECUs were produced for RHD and LHD cars. 197211/201674 does appear to provide slightly more aggressive shock scheduling than 201673, but not enough to warrant changing. Changing 183960, fitted to early RHD and LHD 575Ms, to either 201673 or 201674 will noticeably stiffen up handling.

Note 2: Shock Absorber ECUs 205618 and 205619 being part of the HGTC retrofit kits sold by Ferrari is pure speculation at this point. There is only one retrofitted HGTC 575M in the FerrariChat database, and that is SN 128905. If fitted with 205618 or 205619, that would confirm the speculation. Because the price is nearly double compared to 210673 or 201674, there has been no known retrofit of either of these two ECUs .

Note 3: Beginning at Ass. Nr. 52556, there is no distinction between RHD and LHD Shock Absorber ECUs.

Note 4: FChatters have successfully fitted LHD cars with 201674 with no problems on 2002, 2003, and early 2004 MY cars.

Summary of Shock ECUs Assembly No. 52556 and Later

Part Number 202954: What the parts catalog says:
-Valid from Ass. Nr. 52556-
-Valid till Ass. Nr. 55768-
What we know: Parts catalog description plain and accurate.

Part Number 210577: What the parts catalog says:
-Valid from Ass. Nr. 55769-
What we know: Parts catalog description plain and accurate. Last ECU fitted to non-HGTC 575Ms.

Part Number 210578: What the parts catalog says:
-HGTC Version-
What we know: Parts catalog description plain and accurate.

Note 1: HGTC ECU 201578 can be successfully retrofitted to any 575M, Ass. No. 52556 or later.

Note 2: HGTC ECU 201578 (or any of the late ECUs) will work fine on pre-Ass. No. 52556 cars, but lack of a Steering Position Sensor ECU input from the Motronic ECU will cause a permanent suspension warning indication.
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Markus- It works for me, but it was the same thing I posted with some differences in fonts, colors, etc, but no changes in wording. Try it again, because you might have been trying it during the time I was editing it.

Taz
Terry Phillips

 

Philip- On the closeness of 201673 and 201674 in part numbers, no clue on that or the price differential and there is only a small functional difference either. Note also the last two ECUs, 210577 and 210578 are sequential. Maybe Ferrari reserved sequential part numbers for shock ECUs, who knows? Also if they were produced at around the same time, why was 201673 fitted to some RHD cars instead of 197211 or 201674. The parts catalog infers the order of production was:

183960
201673
197211
201674
205618
205619

To make matters even more confusing, why was my 197211/201674 ECU marked Fiorano H Pack in two places when there was no shock ECU included with FHP? Does the 167/200 indicate only 200 ECUs manufactured? One of our FChatters has an FHP from 2002 with 183960.


Taz
Terry Phillips
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Gianni- Jimmie is correct. There was no FHP specific ECU. FHP cars used the same ECU as the rest of the 575Ms and Superamericas. HGTC had a package specific ECU, FHP did not.

I need to edit the document to show the last two ECUs, 210577 and 210578, were the ECUs fitted to the Superamerica, too.

Taz
Terry Phillips

 

Michael- If you fit the HGTC shock ECU to your car, you will get a permanent suspension fault light because the steering position sensor is missing on your car. So I do not recommend that for owners of early (52555 and earlier Assembly Numbers) 575Ms.

Your car being fitted with 183960 answers one question, though. My speculation that 205618 and 205619 were part of the HGTC upgrade was incorrect. They are just replacements for 201673 and 201674. That is how we learn, by screwing up and then finding out how things really are.

Will edit the document and post tomorrow.

Incidentally, there were several versions of the HGTC upgrade kits, but I have been unable to get complete details on what was included with each.

Taz
Terry Phillips

 

The one HGTC upgrade car for which we have records did not get a new shock absorber ECU, so my speculation 205618 and 205619 might be part of the HGTC upgrade kits was incorrect. Here is a corrected version of the shock absorber ECU document.

Taz
Terry Phillips
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360Grigiotitanio found a typo on the HGTC ECU. Fixed here.

Taz
Terry Phillips
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Graham- I would have to disagree with pretty much everything you said except the part about it being relatively easy to upgrade to HGTC suspension components, if expensive. MSW's hydraulic steering ECU is very affordable, though. 205619 is about 900 pounds from Maranello Classic Parts, without VAT, and there is little difference in function between 201673, 197211, 201674, 205618 and 205619.

We have swapped too many owners from non-FHP to FHP packages to say it makes little difference. So many, we ate most of the NOS FHP components. With the recommended order of replacement being:

Steering ECU
Shock ECU
Rear Anti-Roll Bar (no new FHP bars available, only used and HGTC)
Springs

Owners were still seeing noticeable improvements all through the process and the rear anti-roll bar, FHP or HGTC, noticeably cuts down on understeer and the springs on roll and jounce, regardless of shock ECU.

The part about not worrying about buying an early 575M without FHP is a good point, and nobody here has been saying one must have FHP or it is a no-sale. But FHP is definitely a positive for 575Ms, and even Superamericas without HGTC.