I've had this vehicle for two years and for the last 6-8 months, I've had a myriad of very inconsistent issues. The car ran like a dream when I bought it. No issues and it ran consistently good except for my first "issue" that I noticed early on but figured it was just a sensitive throttle response. When I slow my car down to around 5MPH, for example, stop and go traffic, then immediately press on the gas normally the vehicle jerks forward. The only workaround to it I've found is coming to a complete stop, and then accelerating. Or pressing the throttle extremely lightly and slowly.

The next issue has been going on for a few months, and at first I thought it was the dreaded transmission but I'm not sure: When I quickly accelerate I hear a faint, high pitched grinding noise. It lasts no more than 2 seconds and only happens when I quickly accelerate and get up to speed. I took it to a local transmission repair shop and they test drove it for 13 miles, checked tranny codes, fluid, etc and didn't find anything wrong. This ties into how ridiculously inconsistent these issues are. One day they're happening, the next everything is normal. The transmission does not slip, nor have I gotten any transmission codes which makes me think it's something else.

The next issue is when I am turning at low speeds, I hear a deep growling/rumbling noise that makes everything feel unresponsive and sluggish.

Last but not least, I recently scanned my car for error codes since I've never had any CELs, and this is what came back:

77-02 VSA CAN communication: VSA ECU Fail
41-01 Communication Line (CAN): No Signal/ Performance for PCM ECU
77-01 PCM CAN communication: PCM ECU Fail
61-01 Power Source Failure for ECU (Low Voltage)
62-01 Power Source Failure for ECU (High Voltage)
14-01 Left Front Wheel Speed sensor Signal Failure
86-01 CAN1 Communication Failure
27-01 Steering Angle Sensor Failure
12-01 No description available
11-02 IG1 Power Line Failure
36 Rear Right Tire Sensor Transmission failure
85 CAN Communication Failure
56-31 No description available
61-20 Short In Driver Seat Belt Buckle Switch
B1227 Ambient temperature Sensor Open
B1241 Blower motor Lock Error
B1242 Mode motor Code error (As)

I suspected that my battery was bad, so I went to AutoZone and the battery voltages were normal when turned off, but after testing the alternator with a different tool, the alternator was only hovering around 12-13v. They said what's most likely causing all these codes, is my alternator is starting to give out. Bad voltage regulator maybe? I've had no other traditional alternator issues except for all these sudden codes and my car driving poorly most of the time. I guess if it is the alternator it would explain the inconsistency of some of these issues since this car's computers dictate the performance. What do you think?

 

A friend of mine was a master technician at the local Acura dealership (he recently moved to work for another shop), he said pretty much every alternator on those Acuras fail after 100-150K miles/10 years. It's true for my 2007 RDX and 2010 TL.

On top of that, there are a few other common failures on the gen4 TL (probably not a complete list)

• A/C blend door, both driver and passenger side
• CD player/changer after ~10 years
• Wheel bearings after ~10 years (this is probably not very surprising especially you drive your car hard)

 

That is very helpful, thank you. My TL is hovering right around 97,000 miles so it would make sense that the alternator is starting to show signs of failure. Do you think the high pitched grinding noise and/or the low rumbling noise could be tied to the wheel bearings considering the age?