Sliding Roof Control ECU
OEM Part Number
89720-24010 — Computer Assembly, Sliding Roof Control. Fits all 2002-2010 SC430. No known supersession. [Verified — OEM catalogue]
What It Is
The brain of the retractable hardtop system. This ECU coordinates all ~26 motors, switches, sensors, and latches during the roof open/close cycle. It communicates with door computers (front L/R) via the vehicle’s BEAN (Body Electronics Area Network) multiplex bus. Located in the boot (trunk) near the luggage compartment junction block. [Probable]
Contains approximately 50 proprietary diagnostic trouble codes (DTCs) readable only via Toyota Techstream during an active operation cycle. [Probable]
Fitment
All 2002-2010 Lexus SC430 (UZZ40). Single part number across all model years. [Verified — OEM catalogue and eBay listings confirm 02-08/02-10 fitment]
Key DTCs Managed
| Code | Description |
|---|---|
| B1273 | Sliding Roof ECU Communication Stop — CAN-BUS failure between ECU and other modules |
| B2521 | Roof Close Switch RH Malfunction |
| B2523 | Roof Position Switch No. 1 Malfunction |
| B2527 | Roof Open Switch Malfunction |
[Probable — from technician sources and DTC databases]
Failure Symptoms
- Convertible top completely inoperative (no response to switch) [Probable]
- Communication errors with other vehicle modules [Probable]
- Multiple simultaneous DTCs that don’t resolve with individual component replacement [Reported]
- Water damage — the boot location makes it vulnerable if weatherstrips leak or roof drains block [Probable]
Warning: Corroded or cold solder joints on the ECU circuit board are a documented failure mode. [Reported — HoodTech specialist]
Aftermarket Alternatives
None known. OEM or used only.
Where to Buy
New OEM
- LexusPartsNow: Listed but pricing not displayed. Expect $500-800+ USD based on similar Lexus ECU pricing. [Reported — estimated]
Used
- eBay: Multiple listings for used units, $50-150 USD. Search “SC430 sliding roof control module 89720-24010”. [Verified — eBay listings confirmed April 2026]
- Importapart: ~$82-100 range for used OEM units. [Reported — eBay/retailer listings]
- Wreckers/dismantlers: AH Parts, J&J Auto Wrecking carry used SC430 modules. [Verified — listings found]
ECU Repair Service
- SIA Electronics (siaelec.com) offers SC430 ECU repair services, though their listing references the engine ECU — confirm sliding roof ECU repair capability before sending. [Reported]
- UpFix offers Lexus SC430 ECU repair. Same caveat — confirm they service the roof module specifically. [Reported]
Installation Notes
Located in the boot. Accessible after removing trunk lining. [Probable]
Warning: Before replacing the ECU, diagnose thoroughly. Replacing the ECU when the actual fault is a $25 limit switch is an expensive mistake. Techstream diagnosis first, always. [General advice]
Related Faults
Sources
- LexusPartsNow OEM catalogue
- eBay parts listings (multiple)
- ClubLexus forums: “Trunk/roof module replacement 2002 SC430”
- Importapart, Sutter Imports parts listings