C4 Cactus Mk2 fault code - puretech 1.2 petrol

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tontonjon
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C4 Cactus Mk2 fault code - puretech 1.2 petrol

Post by tontonjon »

Hello! It's been a while.

My Cactus has been giving me a little trouble recently. Funny noises then a new radiator (less than 44000 miles!) then a fault code and "get vehicle reparied" message.

P2176-64 Motorized Throttle Housing (Air Metering Unit): Signal Not Coherent. The code keeps disappearing and reappearing, with no drop in performance (either driving or fuel).

The noise is coming from the throttle housing, says my mechanic. He thinks it may be worn gears and said that it would be a big job to replace because it's difficult to reach.

The question is, what is the 64 part of the code and do I need to worry? Has anyone else had the same issue and had it rectified?

I'll obviously need to get it fixed at some point, but the help online so far has not been very... helpful. Checking, cleaning contacts, replacing the whole thing.

Any help gratefully received.
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GiveMeABreak
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Re: C4 Cactus Mk2 fault code - puretech 1.2 petrol

Post by GiveMeABreak »

That is the proper fault code - 7 alpha / numeric characters. Where there are 7 parts to the code, the last 2 provide more specific detail of the fault.

I'll need your VIN for this vehicle for an explanation. Please post your VIN in full without spaces - it will be automatically masked from public view after submitting your post & will only be visible to staff.
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Marc
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tontonjon
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Re: C4 Cactus Mk2 fault code - puretech 1.2 petrol

Post by tontonjon »

Thank you. I'll do that. Do I post the VIN as a separate quick rely? Just like I've done now?

To make matters worse, the spanner lit up as well this afternoon. I've contacted the garage and I'm going to try and get it fixed.
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tontonjon
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Re: C4 Cactus Mk2 fault code - puretech 1.2 petrol

Post by tontonjon »

VF7**************[VIN obfuscated, can be read by forum staff]
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Re: C4 Cactus Mk2 fault code - puretech 1.2 petrol

Post by GiveMeABreak »

Here you go:
Fault Code: P2176 64
Description of Fault: Motorised throttle housing (Air mixer unit): Signal not coherent. Detection of a motorised throttle housing position out of range fault.
Conditions for Fault to clear: The following conditions have to be met:
- The position of the motorised throttle housing is within the operating range
- Driving for 5 minutes
Switching on of the warning lamp and/or warning message:
- Engine diagnosis warning lamp
- "SERVICE" warning lamp
Downgrade Modes whilst Fault is active:
Symptoms:
  • Growling/whirring/booming
  • Vibration
  • Whistling and whining/hissing/rushing of air
  • Malfunction of the production of warm air
  • Malfunctioning of the demisting/deicing
  • Activation of the cruise control or speed limiter function impossible
  • Deactivation or switching off of the cruise control/speed limiter function
  • Engine hesitating, cutting out
  • Lack of power
  • Absence of automatic stopping of the internal combustion engine
  • Malfunction of the Stop and Start switch or its LED
  • Illumination problem of the "ECO" stop and start warning lamp on the instrument panel
  • Malfunctioning of the engine when idling
  • Starting problem
  • Problem activating the power unit
  • Problem with automatic restarting of the internal combustion engine
Suspect Areas:
  • Motorised throttle housing
  • Electrical harness
  • Engine ECU
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Marc
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tontonjon
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Re: C4 Cactus Mk2 fault code - puretech 1.2 petrol

Post by tontonjon »

Wow.

Thank you very much for all this. I shall pass it on to my garage mechanic to look at. But the noise I have from the housing itself suggests that this needs replacing. It could be the gears inside and that comes under item 1 in the suspect area.

I don't have very many of the symptoms. I suppose the whirring sound, but not the engine; the last symptom is intermittent and has been for ages!

I'll update on outcomes for the benefit of others, but hope no-one needs the same info.
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Re: C4 Cactus Mk2 fault code - puretech 1.2 petrol

Post by tontonjon »

I'va had a discussion with my mechanic; he thinks that the problem is with the throttle and that the noise suggests that something inside is not functioning correctly. The only option seems to be a replacement. He said that 45000 miles is not good for a throttle to be causing problems, but I can't see that there is anything much else to do but to replace it. Even if the contacts need cleaning, the loom needs putting back in place or the ecu is out of sorts, which can certainly be checked first, if the throttle is still making a noise there's something wrong.

Has anyone had this job done? How much time might this take and how much are the parts. I have been told the parts need to come direct from PSA as they are not available elsewhere (and I can't find them online, so this must be right).

Some good news, please!
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Re: C4 Cactus Mk2 fault code - puretech 1.2 petrol

Post by GiveMeABreak »

We can help if you need an original, genuine part number or part diagram, and can't already find the info you need on the Forum. For this service, we do ask for a membership upgrade for official parts data as we are in turn charged for this. It will cover you for future part number requests for up to 2 years, so excellent value.

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tontonjon
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Re: C4 Cactus Mk2 fault code - puretech 1.2 petrol

Post by tontonjon »

OK. I'll see what I can find out from the garage I bought the car from. My mechanic says throttles should last a lot longer than 45000 miles. Not that that helps much!
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Re: C4 Cactus Mk2 fault code - puretech 1.2 petrol

Post by tontonjon »

Right, I have more information.

I'm hoping the image will attach successfully.

Part no 3 is 9803918480 - the grommet
Part no 4 is 9842936880 - the throttle

Costing ... sit down and take a deep breath ... £428. I wonder how many hours labour I have to add to that.

I might get my garage to double check that the part is needed and that it's not something else making the noise before I break the piggy bank.
Attachments
PureTechThrottle.png
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tontonjon
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Re: C4 Cactus Mk2 fault code - puretech 1.2 petrol

Post by tontonjon »

Amazingly, the car was still going well up until today. I've been getting intermittent warnings flashing up, curiously only after stopping for a while and restarting the car - driving from cold without stopping was fine. For a couple of weeks I haven't had any warning lights at all. But I went to visit my garage last Saturday to arrange for a new throttle anyway.

Well, everything has changed now. After driving to town (no issues) I did some shopping. Then into the car and a short drive to the next shop. Then I started out for home and the car beeped, the engine light came on with the diagnostic message and the spanner; I drove off anyway, and then all of a sudden I got the kangaroo petrol effect. I could get up to 12mph, but then it lurched, then change gear to 16mph, lurch... once warmer I managed 20mph, so perhaps I just needed to warm it up a bit. But what really worried me was the noise coming from the fan on hyper-drive.

I've emailed my garage to find out if the throttle is on its way. I think that my luck has finally run out!
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tontonjon
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Re: C4 Cactus Mk2 fault code - puretech 1.2 petrol

Post by tontonjon »

Throttle now replaced. 1hour + parts + consumables + diagnostic = £527.86

A lot for such a small part, especially as it ought to have lasted another 55k miles, I am told.

Still, all done and the car is now ready to drive (or sell!).
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Re: C4 Cactus Mk2 fault code - puretech 1.2 petrol

Post by Kees »

I hope for you, that there is no problem with the distribution belt!!
There are many problems with this type of engine!!