Acura notes that the 2009-2010 Acura TL’s HVAC blower speed may change erratically and VSA DTCs 104 and/or 86 may be stored. The probable cause is a faulty body ground G403. Acura recommends replacing the body ground G403 using hardware kit P/N 61336-TK4-305.
Location of the G403 body ground.
- Move the front seats fully forward and remove the center console rear trim.
- Remove the rear bolts securing the center console, then move the front seats fully rearward.
- Perform the battery terminal disconnect procedure (refer to the repair manual).
- Remove the dashboard center trim. Start at the rear part of each trim and work forward to the dash.
- Remove the dashboard center vent.
- Remove the audio unit or the audio-NAV unit.
- 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.
- Remove the passenger’s dashboard undercover.
- Remove the console carpet trim.
- Remove the dashboard center trim.
- Perform the center console removal procedure, but do not remove the center console from the vehicle. Slide the console towards the rear in order to gain access to body ground G403. The center console also includes the center console RF unit, the center console subharness connector, the parking brake lever mounting bolts (loosen only), the parking brake switch connector and the USB adapter unit connector.
- Remove the G403 ground bolt from the lower joint stay bracket.
- Remove the pierce nut from the lower stay bracket. Insert the original ground bolt a few threads into the pierce nut. Break two pinch welds by pulling the bolt to the driver’s side of the vehicle. Using a center punch, tap the bolt and the nut out through the rear of the bracket.
- Use a file to smooth the edges and remove any burrs from the square opening (where the pierce nut was removed). Note: Place a shop towel inside the center console cavity, under the filing area to prevent metal filings from contaminating any harnesses or components.
- Install a new ground bolt using hardware from the 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 in the square opening, mount a washer and the flange nut on the backside of the lower joint stay bracket.
- Torque the ground bolt to 9 ft-lbf (12 Nm).