My '11 DB9, VIN 13380 has been showing "tire pressure monitoring fault" every time I start the car this year. It lags in reading the tires' pressures, but after a few seconds it reads them correctly and the warning persists even after pressing the "read" button. It's not specific to any tire, and has switched among them all.

While I can live with the tire pressures not being monitored (what did we used to do?), the bigger problem occurred last week when the entire electrical system blinked, or switched down and "crash mode fault" appeared and the car had to coast to a stop and restarted. After a couple days of successful starts the condition cleared out but until I get this resolved the car can't be relied upon.

I've seen this part under the left/rear wheel arch: https://astonmartinbits.com/models/4-DB9/parts/4740 I suspect that the other wheel arches each have their own?

If so, then am I correct that this central part is the problem and crashing the communications bus? https://astonmartinbits.com/models/4-DB9/parts/490 BTW, the battery was just replaced a few weeks ago with the new AntiGravity Lithium Ion. I was hoping the TPMS faults were related to the 2015 battery.

Thanks,
Chris

 

Assuming that the 11 DB9 has the BERU TPMS I would bet you need new sensors. Based upon the link you supplied that was for the BERU system. My 11 V8VS was showing a TPMS fault but still read the pressures as well. The issue was that the voltage in the batteries were low and causing the fault but still had enough left to read the sensors. You can buy a new set of 4 for $145 here: https://www.tpms.com/2011_Aston_Mart...PMS_s/6879.htm I can confirm that these work just fine and just need to be installed by any tire shop for around $100 max. The dealer sell the same sensors for that price per sensor.

 

That sounds promising, as I don't have any indication that the previous owner replaced them in his 10/17 tire change, so they're likely original.

But that now kills my theory as to what's causing the system blink and "Crash Mode Fault, See Operating Manual" (which of course says nothing about this fault). Would it be wise to pick up an OBD reader to better sniff out what's causing this and more easily reset it? What's the best reader?

Thanks,
Chris

 

My theory to the limp modes the computer was going into is that my DB9 doesn't like the Antigravity LiOn battery I put in. There's something about it, either the recharge cycle is different, or their "smarts" are placing signals on the main DC bus that the ECU simply doesn't like. I returned the Antigravity LiOn (they tested it and it was to spec) and installed a new Duracell AGM from Sam's Club (H6 since ours can hold H6, H7, or H8). I've not had any shut-down failures since switching to the AGM battery, so I'm just posting my experience for search-posterity.

I still have the emissions fault lit, but that's pretty common and without pulling the codes and/or going to a dealer, it could be a number of things. As long as it doesn't go into shut-down, I can live with the little things here and there. But shutting down two minutes after leaving, most of the time, is embarrassing for our aspirational car.

 

I'd start with 4 new tire pressure sensors. They have a 8 year life. Do a search on here there's a part number for aftermarket ones. 4 for the cost of 1 OEM. No programming necessary. The module your referencing does not apply to your car.