2022-2023 Honda Civic EPS Gearbox Replacement TSB 23-037

Owners of 2022-2023 Honda Civic vehicles may experience issues with steering effort or unusual noises, even without any warning lights on the dashboard. Honda Service Bulletin 23-037 addresses these concerns, indicating a potential problem with the Honda Civic EPS gearbox.

This bulletin provides detailed instructions for technicians to diagnose and resolve the issue by replacing the EPS gearbox assembly. It's important to note that this problem typically occurs without any diagnostic trouble codes (DTCs) being stored or a Malfunction Indicator Lamp (MIL) being illuminated.

Symptoms

Owners might notice a "Steering effort complaint while driving at moderate or highway speeds." Additionally, there may be a "possible complaint of noise at slow speeds." Crucially, these symptoms occur with "no MIL illuminated or DTC stored," meaning no warning lights will appear on the instrument cluster.

Diagnosis and Cause

The root cause of these steering issues is identified as a "possible steering gearbox malfunction." Technicians will confirm the presence of the described symptoms, as there are no specific diagnostic trouble codes (DTCs) or illuminated warning lights associated with this particular problem. The diagnosis relies on the owner's complaint and the technician's verification of the steering behavior.

Important Warnings for Repair

Honda outlines critical warnings within Service Bulletin 23-037 to ensure proper and safe repair:

• "Do not turn the steering wheel while disconnecting the steering joint." This prevents potential damage or misalignment during the repair process.
• When installing the EPS motor/control unit mounting bolts, technicians are advised: "DO NOT use power tools to install or tighten the bolts." This is to prevent damaging the motor and/or gearbox components.

Repair Procedure Summary

The corrective action involves removing the existing EPS gearbox assembly and replacing it with a new one. The original EPS motor/control unit is retained and transferred to the new gearbox. The repair process, as detailed in Honda Service Bulletin 23-037, includes several key steps:

1. Preparation: Disconnect the 12-volt battery, raise the vehicle, and remove the front wheels.
2. Disassembly: Disconnect the steering joint (ensuring the steering wheel is straight and not turned), remove the engine undercover, and disconnect the EPS harness connectors. Further steps involve removing the rubber exhaust mount, disconnecting stabilizer links, and removing front lower assembly bolts.
3. Subframe Access: Loosen outer tie-rod end nuts, disconnect front lower arms, and remove the engine torque rod front bolt. A subframe adapter (P/N VSB02C000016) is used with a transmission jack to support and remove the front subframe.
4. Gearbox Replacement: Transfer the tie rod ends and steering shaft boot from the old gearbox to the new one. Separate the EPS motor/control unit from the old rack, discard the old O-ring and motor bush, and install a new O-ring (supplied with the new gearbox) on the EPS motor/control unit, applying steering grease. The EPS motor/control unit is then turned two or three times to both the left and right in a 45-degree arc before being loosely installed onto the new gearbox.
5. Reassembly and Finalization: Torque the EPS motor/control unit mounting bolts by hand (not power tools) to 20 N·m (15 lb-ft). Install the new P/S gearbox with the EPS motor onto the subframe, and reassemble all components in reverse order. This includes installing the pinion shaft to the steering joint with a torque of 29 N·m (21 lb-ft).
6. Post-Repair Adjustments: After reassembly, the steering wheel must be centered, and turning revolutions checked. The vehicle is then checked for noise or abnormality by turning the steering wheel fully left and right. Technicians must confirm EPS power assist, ensure the EPS indicator does not illuminate, perform a wheel alignment, and complete VSA Sensor Neutral Position Memorization. Finally, using the Honda Diagnostic System (HDS), an adjustment procedure is performed under the ABS/TCS/VSA menu by selecting "ADJUSTMENT" and then "ALL SENSOR."

Required Tools and Parts

To perform this repair, specific parts and tools are necessary:

Gearbox Assemblies

• Gearbox (4-door Si): Part Number 53640-T22-305
• Gearbox (4-door, 5-door, LX, EX, EX-T): Part Number 53640-T21-306
• Gearbox (4-door, 5-door, Touring, Sport): Part Number 53640-T21-305

Fasteners (Examples)

• Flange Bolt (12x75): Part Number 90161-SX8-T00 (Quantity: 4)
• Washer Bolt (14x85): Part Number 90179-T20-A01 (Quantity: 4)
• Flange Bolt (12x30): Part Number 90174-T20-A01 (Quantity: 2)
• Flange Bolt (10x20): Part Number 90165-THR-A00 (Quantity: 4)
• Washer Bolt (14x45): Part Number 90163-TGH-A01 (Quantity: 2)
• Flange Bolt (14x105): Part Number 90175-TRW-A00 (Quantity: 1)
• Flange Bolt (14x33): Part Number 90164-T20-A00 (Quantity: 5)
• Washer Bolt (14x85): Part Number 90130-T20-A00 (Quantity: 1)
• Flange Bolt (14x35): Part Number 90181-TBA-A00 (Quantity: 2)
• Flange Bolt (14x80): Part Number 90108-T20-A00 (Quantity: 3)
• Split Pin (3.0x22): Part Number 94201-30220 (Quantity: 2)
• Washer Bolt (10x25): Part Number 90159-TBA-A00 (Quantity: 3)
• Self-Lock Nut (12mm): Part Number 90215-SB0-003 (Quantity: 6)
• Flange Nut (10mm): Part Number 90002-S10-000 (Quantity: 2)

Special Tools

• SUBFRAME ADAPTER: Part Number VSB02C000016
• Special Tool/Fixture: Part Number 070AG-SJAA10S

Warranty Information

The repair for the Honda Civic EPS gearbox issue is covered under normal warranty. The operation number for this service is 5131C0, with a flat rate time of 1.9 hours. The defect code is 03001, and the symptom code is 03217. Specific template IDs (A23037A, A23037B, A23037C) and failed part numbers (53640-T22-305, 53640-T21-306) are used depending on the vehicle trim.

Owner Action

If you own a 2022-2023 Honda Civic and are experiencing a "Steering effort complaint while driving at moderate or highway speeds" or a "possible complaint of noise at slow speeds," you should contact an authorized Honda automobile dealer. Since there are "no MIL illuminated or DTC stored," your dealer will need to verify the symptoms to determine if this Service Bulletin 23-037 applies to your vehicle. The repair involves replacing the EPS gearbox and typically takes 1.9 hours.

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Source: NHTSA ID: 10239109