P1153 throttle limits initial settings failed. DS5 THP155

[gwest]

I had previously replied to a thread that described the temperature gauge reading rapidly dropping on a C5. My DS5 did the same thing sometime after a thermostat replacement. Turns out coolant was leaking from the bleeder screw, that I had stupidly over-tightened. I eventually fixed this by using the old screw but transferring the new O-ring to it. But by this time I had engine fault codes and one episode when the car went into limp mode. Since then the car has run fine but has one fault code that won't go away:
P1153: Learning of the initial settings of the motor-driven throttle. Failed in the low stops.
This was based on my Launch 123e reader.
When I got up the courage to connect my newly acquired Lexia 3 interface I got the same fault code (together with a large number of temporary ones that cleared ok). It also reported that the engine ECU was not recognised.
I was using Diagbox version: 07.57, VCI: V.4.3.2, on a laptop with Windows Vista Service Pack 2, Core Duo 2.4 GHz processor, 4 GB RAM, 32-bit operating system with 213 GB of free space on the hard drive. It is painfully slow. I put a battery charger on the car and connected the laptop to mains power. The car went into economy mode eventually.
I had assumed that the erratic readings from the temperature sensor, caused by air in the thermostat housing, were the reason the car's computer had got upset. But the temperature gauge readings have now been stable for several weeks and I have taken it on a 70km drive to give it a chance to settle down. The Launch diagnostic output states that there is still a need for throttle limits programming even though it also has: Throttle limits programming Status : Programming Done. Any suggestions would be most welcome.

[xantia_v6]

I have a 2011 308 with the THP 156 engine, and Lexia has never recognised the ECU. I think that this may be due to a later version of software downloaded to the ECU by the dealer (there were a number of updates to fix or mask reliability problems). I have found that manually selecting the correct ECU variant from the list allows successful communication with the ECU.

[GiveMeABreak]

You may want to update your Diagbox version as I know there were issues in versions earlier than 7.58 concerning the inability to clear errors with the Bosch MED 174* engine ECU on the DS3. V7.58 fixed this and also provides testing by ECU.

[gwest]

Thank you both for the helpful advice. I tried updating the software to vsn 7.58 but it did not help with the engine ECU being recognised. It did however automatically detect the VIN which was convenient. As I understand it the settings for my vehicle (2013 DS5 THP155 DSport) are the following: 5FV MED 17.4.2 Euro 5. At least Diagbox and my Launch scan tool are both giving the same fault codes.
The Launch 123e output has the following information on system identification:
Name of the supplier: Bosch
Function plan number: 9663711580
Operational product references: 9666319583
Software reference: 9692387280
Can you tell me what this actually means?

[GiveMeABreak]

These are various references to the ECU software and ECU mapping.

[gwest]

I can find few examples where throttle body fault codes were caused by an actual faulty throttle body. It seems that throttle body fault codes are often associated with ECU and battery problems.
One ECU example was caused by moisture working its way by capillary action into the ECU connectors, where it caused corrosion. And low battery voltage was also the cause of throttle body fault codes in other cars.
I removed my ECU and inspected the posts and all looked ok. Now that I think about it I should have tried dismantling the multi-plug connectors where you might expect to see the first signs of moisture ingress.
I also removed the air intake pipe to the throttle body and had a look with my endoscope- impossible to see otherwise. Although the throttle body looked oily, there was no obvious buildup of crud. I gave it a good spray with engine degreaser anyway. The part no. on the TB was V760491880-01/ A2C53386322.
I also monitored battery voltage during startup and it fell to 10.1V. The battery that came with the car in 2018 is a Motorgear P56030MF, CCA 525, RC 90 mins.

When I measured some of the adaptation values using my Launch code reader I got the following results:

Programming of accelerator pedal minimum position 1: 8.40mV
Programming of accelerator pedal minimum position 2: 8.50mV
Programming of throttle minimum limit position 1: 585mV
Programming of throttle minimum limit position 2: 4414mV
Throttle limits programming status Programming done

I am curious about the discrepancy between the throttle minimum limits. And what I should do next.

[gwest]

I ran the Launch tool on my other car, a Peugeot 207 Vti and it gave very similar results for the Programming of throttle minimum limit position 1and 2 (585 and 4414mV) so they definitely don't have to be similar readings, unlike the accelerator minimum positions.

I then bought a new battery but it has not made any difference. If anything, the voltage drop on starting is larger. I did give some thought as to why the voltage measured through the OBD port was about 0.5V lower than at the actual battery. (typically 12.0 vs 12.5). But this also seemed to be the same for my Peugeot, and it isn't complaining. Once the car is running the voltage is around 14.

I am still driving the DS5, trying to provoke it, and often have to do a restart to get out of Limp mode. The temperature reading on the instrument panel has been stable since I fixed the leak at the thermostat bleed screw, but recently while cruising on the highway the reading slowly decreased to levels that seemed unreasonable.
On my next DS5 outing I recorded the following temperature data- I used my Launch reader rather than Diagbox because my laptop battery is a bit doubtful.

Controlled thermostat control setting % OCR (what does Optical Character Recognition have to do with this?)
Coolant temperature ºC
Coolant temperature reference value ºC (I presume this is what the ECU is aiming for?)
Modelled coolant temperature (plausibility) ºC (is this a backup for the ECU in case the temperature sensor fails?)

I cannot download the actual data from the reader, just screenshots. The following was shortly after starting out, and I was surprised to see the controlled thermostat setting at 99% when the coolant was only 15C.

My own graphics

The next shot was when the engine was warm.

My own graphics

All the temperature data looked quite smooth, but not the Controlled thermostat settings, which maxed out at 30%.

Next trip I took my 207CC VTi and had a slightly different choice of variables. I chose:
Controlled thermostat control setting %
Coolant temperature ºC
Engine speed
Status of the relay of the fast cooling fan ( I should have chosen Slow fan)

My own graphics

The values for the controlled thermostat for the Peugeot were much more regular and reached 100%.

What am I looking at here – a control problem with the ECU? My only consolation at the moment is that you can never have too many cars when trying to track down problems!

[gwest]

The problem developed further and the list of faults increased:
P1153. Learning of the initial settings of the motor-driven throttle : failed in the low stops.
P3014. Motorised throttle position sensor signal: Programming fault.
P0494. Fan assembly status signal coherence.

I could still drive the car although restarts were needed on occasion to overcome the Limp mode problem. The radiator fan operation was also quite erratic, and it would often stay on after shut-down.

I took some advice and replaced the fan relay unit and it fixed the P0494 problem. For the moment anyway - I only spent $15.75 buying the new replacement unit. At least it is fairly easy to replace.

I had a spare throttle body from a 2103 BMW 118i that had the same part number and after some considerable effort managed to exchange them. The codes P1153 and P3014 have now been cleared and have not come back.
Who would have thought that fault codes associated with the throttle body and the radiator relay actually meant what they said!
I opened the case of the offending throttle body and found no obvious mechanical problems, like stripped teeth, with it.
And I can only surmise that the differences in the operation of the controlled thermostat that I saw in the DS5 and the Peugeot 207 reflect differences in the coolant temperature control regimes?