You may have an issue with the throttle pedal but on all the V12’s I’ve seen there’s a differential of approx. 10 % between PIDs 49 & 4A, see attached image of known good PIDs from a 2009 DBS. Your freeze frame is showing a differential of just over 14%, so it could be slightly out of sync.



On your second report the 49-4A readings look better. Bear in mind that the freeze frame data readings can be recorded a second or so after the DTC has triggered.

Your first report shows a large differential between throttle body PID’s 11 and 47. These are normally much closer together, as shown in your second report.

I would graph every throttle pedal and throttle actuator related PID from both ECU’s and look for any dropouts or deviation between Primary and Secondary readings, this can be done KOEO.



This is the trace from a 2009 DBS throttle pedal showing % PIDs 49 & 4A along with sensor voltages.

 

Thanks for that info. I wrongly assumed that AM was using same value pot position, but I see they are using opposite state logic. At one pedal position, the values are the same as they move in opposite direction and cross. At any pedal position, the sum of the pot voltages is the same (about 4.5 volts). And on the scaled percent map, the difference between the two should always be around 11% or so, as you mention. Seems a little over complicated to me for the purpose of fault detection, but hey, what do I know!

 

So the car is with Aston Martin now. Apparently they need to replace both engine control units first, in order to further diagnose what's wrong with the car. The quotation so far is 27,000 USD.

As the ECUs are faulty (not sure how and if this is common) AM are unable to verify if the other areas have faults too. The ECU receives all the info & readings from other parts of the car to process. It could be that the ECU is causing all the faults. AM will mot guarantee that changing the ECUS will solve all the issues. But without changing the ECU, they won’t be able to diagnose any further.

Is this normal, I always thought Astons were super reliable?

 

Both control module's? $27k someone can't diagnose very well. Chances of both at once I'd buy a lottery ticket. How can a shop install parts that don't fix something and charge you for them. Diagnostic time yes, unnecessary parts NO. It's a computer bad input, bad output. I'd be looking at wires, connectors, pin contact and grounds first.

 

Agree with above. Your dealer is taking you for a ride. If it is a computer, they should have one to use as a known good slave unit to verify that it fixes the problem, and only then, order one. They cannot charge you for buying parts that you may not need. Tell us who the dealer is; maybe we can suggest a more competent outfit, even if you have to ship your car.

BTW, in your last screen capture, I noticed that the P0606 microprocessor error switched from Secondary to Primary. If both ECUs were bad, you might guess that the micro error was fatal, but then why would it disappear from the secondary and then show up on the primary? The chance of both ECUs failing at the same time is remote in the extreme.

 

I'm in Singapore so we don't have the luxury of workshops helping to fix this. There's only one AM workshop here so it's either I fix it or I don't. Would love to hear thoughts and advice here.

They seem to be doing what they can but its a shame that I have a suspicion that I am being taken for a ride

 

If the dealer continues on the line of making you buy two ECUs, you need to elevate the problem to Gaydon. You can e-mail Andy Palmer directly, or maybe start with Aston Martin Works for assistance. Don't accept what your dealer is telling you.

 

Thanks XJRS Owner - how does one email Andy Palmer directly, is it just via contact on the Aston Martin site?
- I personally don't have his email address but yes would love to contact someone in Gaydon that can help.

I feel like this ECU saga is the beginning of something bigger (money wise) and I'm just very sad at this moment.

 

Check on Pistonheads, Aston sub forum. Several posters there have gotten direct response from Palmer. You should be able to find the contact by doing a search on that forum.

 

So I emailed Aston Martin Gaydon on their website. Got a response within 24 hours (from AM Singapore Lagonda office) stating that they would speak with the management at AM dealership who currently have my car. I must admit the office guy was super friendly, professional and very swift to react.

Long story short, I feel a lot more at peace, now that I'm not being shoved a very unacceptable quotation and "diagnosis" I just hate the feeling of being at the mercy of a sole dealership and being bullied in to a take it or leave it situation.

I received a new quote today for the same work
- to replace both ECUs @ $12k USD (previously $27k USD quote) but I have to give back both my old ECUS, which was a strange request.
- I'm going ahead with changing both ECUs as the labour charge in Singapore is $500USD per hour. So didn't want the hassle of changing one. Then accumulating more labour costs for changing the second.
- There's still a lack of trust and faith in AM Singapore on my end.

Basically from an email (because of your great advice) the bill has been slashed by ~66%!

So I'm going ahead with the fix, hoping that it really is a fix.

 

So did this fix your vehicle? You never followed up to let anyone know.

 

Apologies - totally dropped the ball on this one.

Ended up putting 2 brand new ECUs in (@12kUSD incl labour) as per Wearnes who represent AM in Singapore, car seemed fixed. 1 week later, the dreaded CEL came on after you gas it a bit (but disappears after ignition goes off/on) and consistently comes on/off.
- 1 month later I ended up selling the car at a big loss... The buyer exported it to the UK and it's for sale here (I have no affiliation to it).
- Ended up going back to a 997/911.

TBH I'm pretty scarred for life with AMs, mainly due to the experience with Wearnes and being at the mercy of their prices/decision making.
- Still the most beautiful car I've ever and will probably own and the V12 is truly missed. If I lived in the US/UK I'd consider owning a DBS again

 

I'm sorry to hear that. I appreciate you taking the time to give an update though. Some of us are experiencing similar hard-to-find issues and extensive forum experience is hard to come by for these cars, so I was hoping yours was solved. Hopefully mine is eventually figured out and can contribute a bit without letting go of the car.

 

I'm just investigating this same fault on my 2006 DB9 and there's a very obvious reason for this. It's not an over complication at all, it's because the same potentiometer is used for both sides of the pedal, so when it's mounted in the mirror image, the action is the opposite.

 

• P2106 means that the throttle actuator control system pedal follower is seeing a sensor feed fault or there's a problem with the actuator circuit.
• P0104 means that MAF sensor is seeing a rationality check error, or in plain English, it's seeing "backflow" through the MAF. MAF 1 is seeing low voltage and the difference between the two MAFs is greater than 30.23g/s.
• P0121 means that the throttle position sesnor 1 is operating out of its usual range. This is known as a closed in bore out of range fault.
• P0606 means that the AICE processor that controls the NNMM (Neural Network Misfire Management) function, can't communicate with the other processor in the Visteon EEC-VI engine management system.
• P2105 means that the E-Quizzer processor in the Visteon EEC-VI engine management system has detected a serious fault with the throttle actuator control system and has shut it down.
• P2111 means that the throttle plate is stuck open more than 6°.
• P2135 means that the throttle position sensors have failed there rationality check and the voltage difference is more than 0.73v.
• P1797 means that the CANbus messages from the transmission control unit are taking more than 750ms.
• P2138 means that the pedal position sensor has failed it's rationality check.