Where is the EPB module on a 308?

[webs666]

Hi guys,

I have, what is sounding uncomfortably familiar on this forum, EPB issues. I'm not going to go into detail on the fault just yet as there are a lot of other great posts here that I want to work through first, but can somebody tell me please where the parking brake module is located please, like the one pictured here:

https://www.cdsdismantlers.com/part-det ... 294638/770

Sorry I know this is probably a daft question but I'm trying to troubleshoot everything before I run completely out of money.

Thank you so much for any help.

[webs666]

Sorry should add it's a 2014 Peugeot 308 feline. Thanks.

[GiveMeABreak]

We'll need the VIN to determine exactly what 308 you have and equipment first. 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.

I'm assuming you have a T9 as the earlier versions didn't have an EPB. In this case there is no 'module'. The EPB has an operating switch in the cabin and has motors in the rear calipers. The system is controlled by the ESP system.

Secondly, I think it will be easier to just tell us what the issue is as the part you have linked to is nothing to do with the EPB - that is a parking assistance ECU.....

[webs666]

Hi Marc. Thank you so much for your reply. I'm at work at the moment but this evening I can share my VIN and a full diagnostics report. But just for you to mull over, here is the fault. Sorry it's a long one. The stress of this is killing me....

I'll try to keep this concise but there's a lot to mention here.

I have a fault with the EPB, whereby the handbrake will not engage and there are numerous warning messages and the usual sirens screaming at me.

After taking it to Peugeot the fault seemingly progressed, and the handbrake was stuck on. They then told me the two rear handbrake motors were acting in reverse to one another, then they would work, then neither would, seemingly at random.

They checked the wiring, did a systems update, checked the switch and told me I'd need to pay 1k for new callipers, rotors and pads on both rear wheels, which may not even fix the issue. There's no way I can do that.

I've taken the car back off of them (currently the parking brake actuators are unplugged so they won't seize on). I was hoping it was going to be a case of just replacing the parking brake motor but I'm now not so sure. I have a new warning on my dash now, about an ESP fault.

I plugged the handbrake motors back in and ran my own diagnosis last night but don't have the fault codes to hand now annoyingly. There was a fault with a speed sensor, and another with the cars radar technology for cruise control and automatic braking. I had two fault codes for both left and right rear brake actuators but STUPDILY, I don't know if I'd cleared these faults before plugging the handbrakes back in, so these may be older.

The reason I was asking about the brake module is because because another user on here said that he traced the problem back to that box and that it fixed his handbrake. Just hoping really. Just so you know, all 4 brake callipers seem to react fine, no locking up and no pulling under braking and the hill start assist holds the car fine.

ANY ideas at all?

Peugeot have told me they've checked the wiring, but I've seen so many people reporting this was the issue and they were not the best mechanics at all.

I'm asking for help with finding any relevant wiring looms or control units to test. I don't believe two handbrake actuators would go bust together, I think this has to be electrical. It's worth mentioning I had this issue pop on about 3 months ago, but turning the car off and on again fixed it.

I haven't got the money right now for more lengthy garage time, so any hometests I can perform would be amazing. Even if that only narrows the problem down a bit to save labour hours when I do take it in.

Any help whatsoever would be fantastic. I'm honestly losing my mind.

Lee.

[GiveMeABreak]

Hi Lee

A few things you need to understand first:

The EPB system is controlled entirely by the ESP ECU - which apart from handling functions like the stability control of the vehicle and braking strategies, also controls the application of electric parking brake. There are 2 types generally used - some vehicles have a separate motorised control unit that physically pulls and releases the rear hand brake cables attached to the calipers and the system you have which has motorised calipers. So ignore what others have said and focus on the system you have as the other system may be totally different and therefore irrelevant to the one you have.

You will get all sorts of ESP warnings - this is to be expected and is simply because the ESP ECU controls the operation of the handbrake application. When there is a fault, it will deactivate some functions like hill start and other features for safety reasons. The warnings can be alarming as you may tend to think there are more problems than there actually are.

As to what is causing this issue is the hard part. Personally, I doubt it is the calipers at all - they will just apply or release as commanded. Therefore I am leaning on the side of the electrical signals. If the wiring or the CAN Data network connections are damaged it may be that the incorrect signals are being sent causing the motors to apply and release.

It sounds like Peugeot don't understand the issue and are reverting to the default cop-out position of 'replace everything, but it might not fix the issue'.

This is where it does need some investigation and live data to see what is happening and this will mean some specialist diagnostics quite possibly.

So my first thoughts would be has any work been done near the time or just previous to this problem starting - and this can mean any work on the battery, the wheels / tyres / brakes discs etc by another garage?

It is a very common problem where work has been undertaken and a sloppy mech has unplugged or dislodged a wiring connector, or damaged it undertaking other work. These vehicles have computer networks that use multiplexing to reduce wiring, This means that the ECUs send data along the wires that are coded for specific ECUs and ignored by others on the network. So if these signals become corrupt or there is a short on the network it can cause random events to occur. This may explain why, if electrical signals are being sent erratically to the EPB calipers.

[webs666]

Marc, I feel like you've done more to explain this issue to me than any single member of Peugeot. Thank you so much for your response. (I can't talk about Peugeot dealers at the minute ute, my blood pressure rises too high).

So no work that I know of, but 3 things that may be relevant:

1. I've only had the car 6 months so there possibly was beforehand

2. The wheel which we think is the offender has a different brake caliper to the others - as if this has happened before

3. I used my car to jump start another (a french car jump starting a German car, who'd have thought it?). After this, the drivers window seems to misbehave and won't always come back up or takes many, many attempts.

Could this have anything to do with it?

If it were your car, where would you start investigating? I'm gonna strip off the back wheels tonight and have a look, where is it that these wires usually break?

Thanks again for your help, I appreciate it so much.

[webs666]

Also last night I noticeded for the first time ever that the brake lights were staying on until I locked the car, if this helps? Please tell me a faulty break switch can cause all of this?

[RichardW]

A faulty break switch could certainly cause issues. Be interesting to see what fault codes you have - my Dad's C4 Picasso threw a strop with the handbrake this week, but garage can find nothing wrong....!

The wires in question run back from the motors along the rear trailing arms (assuming the same as the C4 Picasso, which is pretty likely!) - the wires are just in the plastic conduit, and they rub through on the conduit. I've just repaired an ABS wire on our C4 Picasso for this fault. Video here for a C4 Picasso:

[GiveMeABreak]

This new information may well be relevant as again, we've had issues here of people damaging their vehicles from jump starting other vehicles, so that is a distinct possibility, and also given the issue with the brake lights. This is not normal behaviour for them to stay on, but it is possible that this may be the result of the same issue where some damage has occurred resulting in some random erratic behaviour or indeed the brake switch as Richard says.

The EPB system on your vehicle only operates on the rear calipers. There can be a couple of variants depending on build date.

I don't have a wiring diagram for this vehicle, but it may be the engine fuse box or supplies & protection management unit. It's really hard to make a diagnosis on a Forum as you can appreciate.

[webs666]

Honestly, without sounding like a broken record thank you so much. All of this is so valuable, cheers to you all!

So I'm feeling a little more confident this evening as actually clearing the diagnostics in between tests has revealed that it's actually just the left actuator with a fault. Surely that means my chances of this being a dodgy handbrake motor and not a full electrical fault has just increased? I've ordered a new handbrake motor, fingers crossed. I don't think it'll be that easy but it's the one thing I have most control over right now. Quick question... I've read all about people not retracting the handbrake motors and ruining their callipers... if I'm just changing the handbrake motor itself and I leave the calliper mounted, am I okay to just go ahead and swap them over without putting the brakes into service mode?

That video is gold. I would have been looking for a far greater split than that. The next bit ofd daylight I have, I'm out tracing my hands along that cable as far as I can. Any thoughts on the below?

Anti-lock Braking System (ABS) Or Electric Stability Program (ESP) - C1560 - Electric Parking Brake (FSE) Left-hand Actuator - Permanent
Engine ECU - P2426 - Control Of The Bypass Of The EGR Exchanger. Short Circuit To Earth - Intermittent
Engine ECU - P0031 - Oxygen Sensor Heating. Short Circuit To Earth - Intermittent
Engine ECU - P0102 - Air Flow Measurement. Signal Incoherent (Frequency Too Low) -Intermittent
Air Bags - U1802 - Vehicle Speed Data Fault - Data Received Invalid