Fixing erratic Acura blower speed

This applies to all 2009 – 2010 TL vehicles. The HVAC blower speed changes erratically and VSA DTCs 104 and/or 86 are stored. The probable cause is a faulty ground G403. Replacing the faulty body ground requires hardware kit P/N 61336-TK-305, and tool kit KTC Trim Tool Set T/N SQJATP2014. The flat rate time is estimated at 1.7 hours.


This procedure is an outline that you can also use as a checklist for the repair. If you need more details, bookmark the procedures in the 2009-2010 TL Service Manual.

* Center console rear trim removal/installation

* Center console removal/installation

* Battery terminal disconnection and reconnection

* Dashboard center trim removal/installation

* Dashboard center vent removal/installation

* Audio unit or audio-navigation unit removal/installation

* Center console panel removal/installation

* Passenger’s dashboard undercover removal/installation

* Center console disassembly/reassembly

* Center console removal/installation

1. Move the front seats fully forward and remove the center console rear trim.

2. Remove the rear bolts securing the center console, then move the front seats fully rearward.

3. Perform the battery terminal disconnect procedure.

4. Remove the dashboard center trim. Start at the rear part of each trim and work forward to the dashboard.

5. Remove the dashboard center vent.

6. Remove the audio unit or audio/navigation unit.

7. Remove the center console panel. The center console panel also includes the shift lever boot base (A/T), A/T shift panel, Shift knob (M/T), seat heater switch connectors, A/T gear shift position indicator light connector, and the accessory power socket connector.

8. Remove the passenger’s dashboard undercover.

9. Remove the console carpet trim (you need to remove the console carpet trim to detach the clips and release the hooks to the center console).

10.Remove the dashboard center trim.

11. Perform the center console removal procedure, but do not remove the center console from the vehicle. Slide it rearward to allow access to the body ground G403. The center console also includes the center console RF unit, center console subharness connector, parking brake lever mounting bolts (loosen only), parking brake switch connector and USB adapter unit connector.

12. Remove the G403 ground bolt from the lower joint stay bracket.


13. Remove the pierce nut from the lower stay bracket (insert the original ground bolt by a few threads into the pierce nut, break two pinch welds by pulling the bolt towards the driver side of the vehicle, and using a center punch, tap the bolt and the nut out through the rear of the bracket.


14. Use a file to smooth the edges and remove any burrs from the square opening (where the pierce nut was removed). Be sure to place a shop towel inside the center console cavity, under the area you are filing to prevent contamination of harnesses or other components.


15. Install a new ground bolt (included in the hardware kit).

* Insert the ground bolt into the G403 ground terminal

* Insert the ground bolt through one of the washers

* Insert the ground bolt through the square opening on the lower stay bracket

* Make sure that the anti-rotation tab on the terminal is inserted into the anti-rotation hole located below the square opening

* With the ground bolt inserted into the square opening, mount a washer and the flange nut on the back side of the lower joint stay bracket

* Torque the new ground bolt to a value of 9 lb-ft (12 Nm)


16. Reinstall the parts in the following order:

* Center console

* Center console RF unit

* Center console subharness connector

* Parking brake lever mounting bolts

* Parking brake switch connector

* USB adapter unit connector

* Console carpet trim

* Passenger dashboard undercover

* Center console panel

* Audio unit or audio-navigation unit

* Dashboard center vent

* Seat heater switch connectors

* A/T gear shift position indicator light connector

* Accessory power socket connector

* A/T shift panel

* Shift lever boot base (A/T)

* Shift knob (M/T)

* Dashboard center trim

* Perform the battery terminal reconnection procedure

* Move the front seats forward

* Center console rear trim

*Make sure that all clips, hooks and screws are securely attached. Replace any damaged clips.

Tags: Acura  HVAC 
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