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Cadwell Parker

Pedestrian protection fault - Do not open bonnet

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I had this fault appear on the F11 earlier. ''Pedestrian protection. Do not open bonnet. Drive moderately to nearest service centre.

 

Ista shows fault code 9303AC

 

pedestrian-fault.jpg

 

I cleared the fault and it didn't return when I switched on the ignition again. Hopefully that'll be the last I see of it but maybe something to keep an eye on?

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Highly likely the megathin wiring in the left bonnet catch is becoming loose or damaged.

Fiddly to resolder when you find a break, but not a massively expensive problem to deal with.

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I'll get a look later if it stops raining. At least the warning has gone for now so I can open the bonnet without upsetting anything else 

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This fault returned after driving for about 50 miles yesterday. I've cleared it again and driven anotger 30 miles or so without seeing it again but no doubt it'll return soon. 

 

I had a quick look at the wiring I could see going to the bonnet catch and also around the actuator at the hinge but there's nothing obviously rubbing/wearing/loose. Is there any way I can use ISTA to track the problem down more accurately or is it just a case of visually checking the wiring? Looking on Newtis it I can see the sensors are behind the bumper. Is it likely to be anything going on in there?

 

The warning against opening the bonnet is somewhat concerning. I'm not sure what might happen if I open it while the warning's still active but would like to get to the bottom of this before it gets to the stage of being permanently on.

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There are essentially 5 parts to the system:

Front left and right are the two bonnet catches

Rear left and right are the two pyrotechnic units

Frontal sensor is the strip behind the bumper.

 

Your report  of front left, resistance too high will be the front left catch area and the resistance being a breaking/broken cable. The cables in that area go to a yellow multiplug which you'll see when you lift the flap. As long as your ignition is turned off, the system is disarmed, so I wouldn't be any more cautious than normal about opening the bonnet to inspect.

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Thanks @HandyAndy_UK

 

I saw the yellow plug there yesterday so will get a closer look tomorrow. Maybe just the multiplug needs cleaning up. I'll separate the two halves, give them a dose of switch cleaner and have a closer look at the cables while I'm there.

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If it were rear left or right, then possibly, but as the reported fault was front left it will be the latch. 

Having rebuilt the front of mine, annoyingly it's a system I'm far too familiar with :-(

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7 hours ago, 535i Andrew said:

 

Check your scuttle drains

 

I was looking at that the other day following all the torrential rain we've  had. There's a little water at the very bottom but nothing much to worry about. 

 

I opened the multiplug earlier but it looks clean and dry so I dont think that's the problem. Also tried to get a closer look at the cables running to/from it but again can't see anything obviously wrong. Perhaps there's some wear being hidden by the sheathing on the cables and some further dismantling might be required. Also I can't really see the end of the cables after they curl under and disappear into the bonnet latch mechanism so perhaps I need to move the latch from its mounting to get a better look. 

 

Having poked around I was hoping the fault might have reappeared following my disturbance of the wiring, giving some indication of the location of the problem but as yet nothing is showing.

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If there's nothing obvious immediately around the catch you might need to follow the wires a little. Front left is going to include the whole wiring to that bonnet latch, sadly.

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On 06/08/2019 at 15:19, Cadwell Parker said:

 

I was looking at that the other day following all the torrential rain we've  had. There's a little water at the very bottom but nothing much to worry about. 

 

I opened the multiplug earlier but it looks clean and dry so I dont think that's the problem. Also tried to get a closer look at the cables running to/from it but again can't see anything obviously wrong. Perhaps there's some wear being hidden by the sheathing on the cables and some further dismantling might be required. Also I can't really see the end of the cables after they curl under and disappear into the bonnet latch mechanism so perhaps I need to move the latch from its mounting to get a better look. 

 

Having poked around I was hoping the fault might have reappeared following my disturbance of the wiring, giving some indication of the location of the problem but as yet nothing is showing.

All the water should be draining without hindrance. I suspect you have biofilm build up which stops the flaps from opening properly at the base and the water leaving. There is a number of drains around there so it should drain quickly and easily away from those areas. 

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