What's the black box under the throttle pot?
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- Captain Jack
- 3.0 24v
- Posts: 3820
- Joined: Sun Aug 07, 2005 11:26 am
- Location: Langford, Somerset
What's the black box under the throttle pot?
As subject really...
During the weekend I noticed that one of the thick wires that bolts to one of the er... bolts on this little black box under the throttle position pot is charred and the plastic around the bolt melted due to arcing (it's the smaller bolt). The bolt itself is loose, I tried tightening the nut but this didn't help. It looks like the bolt has come loose inside.
What is this box?? I haven't noticed anything untoward in the car electrical wise. On the side of it says "Relais", which I guess means relays in French. What relay? Glow plug relay? Thought that was inside the ECU? It seems to start fine as well... but I guess HDIs aren't as sensitive to cold as other diesels.
During the weekend I noticed that one of the thick wires that bolts to one of the er... bolts on this little black box under the throttle position pot is charred and the plastic around the bolt melted due to arcing (it's the smaller bolt). The bolt itself is loose, I tried tightening the nut but this didn't help. It looks like the bolt has come loose inside.
What is this box?? I haven't noticed anything untoward in the car electrical wise. On the side of it says "Relais", which I guess means relays in French. What relay? Glow plug relay? Thought that was inside the ECU? It seems to start fine as well... but I guess HDIs aren't as sensitive to cold as other diesels.
2003 - 2008: 1998 Peugeot 406 2.1 TD 110bhp LX Saloon
2008 - 2009: 2004 Honda Accord 2.2 CDTI 136bhp Executive Saloon
2009 - 2013: 2002 Peugeot 406 2.0 HDI 110bhp Executive Saloon
2013 - 2021: 2007 Peugeot 407 2.2 HDI 170bhp Executive Saloon (mapped to 213bhp
)
2021 - ????: 2016 Ford Mondeo 2.0 TDCi 180bhp Titanium
2008 - 2009: 2004 Honda Accord 2.2 CDTI 136bhp Executive Saloon
2009 - 2013: 2002 Peugeot 406 2.0 HDI 110bhp Executive Saloon
2013 - 2021: 2007 Peugeot 407 2.2 HDI 170bhp Executive Saloon (mapped to 213bhp

2021 - ????: 2016 Ford Mondeo 2.0 TDCi 180bhp Titanium
- steve_earwig
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Re: What's the black box under the throttle pot?
I "think" that's the glow plug relay on early HDis. Just going into Service Box for Highlander...

Thisun?
There's two, pre EOBD (598138) and post (598140), I'm guestimating about 35 squid.

Thisun?
There's two, pre EOBD (598138) and post (598140), I'm guestimating about 35 squid.
Unskilled meddling sin©e 2007
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- Captain Jack
- 3.0 24v
- Posts: 3820
- Joined: Sun Aug 07, 2005 11:26 am
- Location: Langford, Somerset
Re: What's the black box under the throttle pot?
That's the jobbie!
Can I take it apart and "fix" the bolt or would I be better off just replacing the thing?
Can I take it apart and "fix" the bolt or would I be better off just replacing the thing?
2003 - 2008: 1998 Peugeot 406 2.1 TD 110bhp LX Saloon
2008 - 2009: 2004 Honda Accord 2.2 CDTI 136bhp Executive Saloon
2009 - 2013: 2002 Peugeot 406 2.0 HDI 110bhp Executive Saloon
2013 - 2021: 2007 Peugeot 407 2.2 HDI 170bhp Executive Saloon (mapped to 213bhp
)
2021 - ????: 2016 Ford Mondeo 2.0 TDCi 180bhp Titanium
2008 - 2009: 2004 Honda Accord 2.2 CDTI 136bhp Executive Saloon
2009 - 2013: 2002 Peugeot 406 2.0 HDI 110bhp Executive Saloon
2013 - 2021: 2007 Peugeot 407 2.2 HDI 170bhp Executive Saloon (mapped to 213bhp

2021 - ????: 2016 Ford Mondeo 2.0 TDCi 180bhp Titanium
- steve_earwig
- Moderator
- Posts: 19813
- Joined: Thu Oct 04, 2007 6:09 pm
- Location: Jastrebarsko, Croatia http://www.jastrebarsko.hr/lokacija/
Re: What's the black box under the throttle pot?
I don't know if they're repairable, what we need is a guineapig... 

Unskilled meddling sin©e 2007
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- Captain Jack
- 3.0 24v
- Posts: 3820
- Joined: Sun Aug 07, 2005 11:26 am
- Location: Langford, Somerset
Re: What's the black box under the throttle pot?
After this weekend, my desire and confidence in diagnosing and repairing issues myself is not what it used to be...
2003 - 2008: 1998 Peugeot 406 2.1 TD 110bhp LX Saloon
2008 - 2009: 2004 Honda Accord 2.2 CDTI 136bhp Executive Saloon
2009 - 2013: 2002 Peugeot 406 2.0 HDI 110bhp Executive Saloon
2013 - 2021: 2007 Peugeot 407 2.2 HDI 170bhp Executive Saloon (mapped to 213bhp
)
2021 - ????: 2016 Ford Mondeo 2.0 TDCi 180bhp Titanium
2008 - 2009: 2004 Honda Accord 2.2 CDTI 136bhp Executive Saloon
2009 - 2013: 2002 Peugeot 406 2.0 HDI 110bhp Executive Saloon
2013 - 2021: 2007 Peugeot 407 2.2 HDI 170bhp Executive Saloon (mapped to 213bhp

2021 - ????: 2016 Ford Mondeo 2.0 TDCi 180bhp Titanium
Re: What's the black box under the throttle pot?
It's fairly common for these bolts/nuts to come loose and arc badly, burning the connections.I would replace the whole box if I was you.
Don't let your confidence take a dent, CJ, it happens to us all, no matter how much experience you have. The car repair business can seriously bite you sometimes.
The thing is, with this being my living I just have to forget the aggro and get on with the next job.There will be more aggro just around the corner.
People don't understand when you give a price for a job that there are hidden problems that the DIY person just doesn't see until they have a go themselves.
I do not intend any criticism of yourself.
Don't let your confidence take a dent, CJ, it happens to us all, no matter how much experience you have. The car repair business can seriously bite you sometimes.
The thing is, with this being my living I just have to forget the aggro and get on with the next job.There will be more aggro just around the corner.
People don't understand when you give a price for a job that there are hidden problems that the DIY person just doesn't see until they have a go themselves.
I do not intend any criticism of yourself.
- Captain Jack
- 3.0 24v
- Posts: 3820
- Joined: Sun Aug 07, 2005 11:26 am
- Location: Langford, Somerset
Re: What's the black box under the throttle pot?
Thanks for the kind words, Jasper.
After this weekend, every single bone and muscle in my body is aching. I don't know how people do this every day - they are heros! Of course, it helps having the right tools and knowledge but still...
After this weekend, every single bone and muscle in my body is aching. I don't know how people do this every day - they are heros! Of course, it helps having the right tools and knowledge but still...
2003 - 2008: 1998 Peugeot 406 2.1 TD 110bhp LX Saloon
2008 - 2009: 2004 Honda Accord 2.2 CDTI 136bhp Executive Saloon
2009 - 2013: 2002 Peugeot 406 2.0 HDI 110bhp Executive Saloon
2013 - 2021: 2007 Peugeot 407 2.2 HDI 170bhp Executive Saloon (mapped to 213bhp
)
2021 - ????: 2016 Ford Mondeo 2.0 TDCi 180bhp Titanium
2008 - 2009: 2004 Honda Accord 2.2 CDTI 136bhp Executive Saloon
2009 - 2013: 2002 Peugeot 406 2.0 HDI 110bhp Executive Saloon
2013 - 2021: 2007 Peugeot 407 2.2 HDI 170bhp Executive Saloon (mapped to 213bhp

2021 - ????: 2016 Ford Mondeo 2.0 TDCi 180bhp Titanium
Re: What's the black box under the throttle pot?
You're very welcome CJ
I've been doing this job for 40 years come 2nd of march

I've been doing this job for 40 years come 2nd of march

Re: What's the black box under the throttle pot?
It's working in temperatures like this I can't fathom - I can't touch my dad's tubby in my garage because my tools freeze my hands, the car freezes my hands, everything I do in the garage results in frozen hands! Can't even manage to put a nut on a thread without dropping the ****ing thing 5 times and not even realisingCaptain Jack wrote:I don't know how people do this every day - they are heros!

<steve_earwig> I think this forum is more about keeping our cars going with minimal outlay than giving our cars more reason to go bang
- Captain Jack
- 3.0 24v
- Posts: 3820
- Joined: Sun Aug 07, 2005 11:26 am
- Location: Langford, Somerset
Re: What's the black box under the throttle pot?
Yes, temperature is a killer too. I am still recovering today and am working from home in my bed with my cat.
I don't have a garage (well, my parents do but it's full of junk) so I had to dress up fairly warm. Two pairs of trousers (tracks + jeans on top), loads of upper body clothes including an old but warm winter coat, 2 pairs of socks, a hat and old sheepskin gloves. Kept me relatively warm, but constant hammering helped!
I don't have a garage (well, my parents do but it's full of junk) so I had to dress up fairly warm. Two pairs of trousers (tracks + jeans on top), loads of upper body clothes including an old but warm winter coat, 2 pairs of socks, a hat and old sheepskin gloves. Kept me relatively warm, but constant hammering helped!
2003 - 2008: 1998 Peugeot 406 2.1 TD 110bhp LX Saloon
2008 - 2009: 2004 Honda Accord 2.2 CDTI 136bhp Executive Saloon
2009 - 2013: 2002 Peugeot 406 2.0 HDI 110bhp Executive Saloon
2013 - 2021: 2007 Peugeot 407 2.2 HDI 170bhp Executive Saloon (mapped to 213bhp
)
2021 - ????: 2016 Ford Mondeo 2.0 TDCi 180bhp Titanium
2008 - 2009: 2004 Honda Accord 2.2 CDTI 136bhp Executive Saloon
2009 - 2013: 2002 Peugeot 406 2.0 HDI 110bhp Executive Saloon
2013 - 2021: 2007 Peugeot 407 2.2 HDI 170bhp Executive Saloon (mapped to 213bhp

2021 - ????: 2016 Ford Mondeo 2.0 TDCi 180bhp Titanium
- Welly
- The moderator formally known as Welton
- Posts: 15033
- Joined: Tue Jan 10, 2006 12:52 pm
- Location: East Midlandfordshire
Re: What's the black box under the throttle pot?
Captain Jack wrote:Two pairs of trousers (tracks + jeans on top), loads of upper body clothes including an old but warm winter coat, 2 pairs of socks, a hat and old sheepskin gloves
Reminds me of a Party game

Cars in my care:
2021 Kia Spottage 1.6 Pez Turbo Dual Clutch Gearbox Trickery
2013 Renner Twingo - donkey work
2021 Kia Spottage 1.6 Pez Turbo Dual Clutch Gearbox Trickery
2013 Renner Twingo - donkey work
- DaiRees
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Re: What's the black box under the throttle pot?
Yeah I know what you mean, I'm ashamed to say that I've booked the car in to have the back brakes replaced. Been carrying the new discs, pads and shoes around in the boot for ages, been too busy to to do them but now the MOT's looming and it's just too bloody cold out there!mjb wrote:It's working in temperatures like this I can't fathom - I can't touch my dad's tubby in my garage because my tools freeze my hands, the car freezes my hands, everything I do in the garage results in frozen hands! Can't even manage to put a nut on a thread without dropping the ****ing thing 5 times and not even realising
- steve_earwig
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- Joined: Thu Oct 04, 2007 6:09 pm
- Location: Jastrebarsko, Croatia http://www.jastrebarsko.hr/lokacija/
Re: What's the black box under the throttle pot?
Pah, get out there, it's lovely
(my hand stuck to the garden gate this morning...)

Unskilled meddling sin©e 2007
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- Captain Jack
- 3.0 24v
- Posts: 3820
- Joined: Sun Aug 07, 2005 11:26 am
- Location: Langford, Somerset
Re: What's the black box under the throttle pot?
Having some bad troubles starting from cold, takes a good few cranks in the morning to get it going (about 1 minute of on/off cranking). As I never actually got around to fixing this, I think I'll need to get a new relay.
Anyone has one in a decent nick?
Anyone has one in a decent nick?
2003 - 2008: 1998 Peugeot 406 2.1 TD 110bhp LX Saloon
2008 - 2009: 2004 Honda Accord 2.2 CDTI 136bhp Executive Saloon
2009 - 2013: 2002 Peugeot 406 2.0 HDI 110bhp Executive Saloon
2013 - 2021: 2007 Peugeot 407 2.2 HDI 170bhp Executive Saloon (mapped to 213bhp
)
2021 - ????: 2016 Ford Mondeo 2.0 TDCi 180bhp Titanium
2008 - 2009: 2004 Honda Accord 2.2 CDTI 136bhp Executive Saloon
2009 - 2013: 2002 Peugeot 406 2.0 HDI 110bhp Executive Saloon
2013 - 2021: 2007 Peugeot 407 2.2 HDI 170bhp Executive Saloon (mapped to 213bhp

2021 - ????: 2016 Ford Mondeo 2.0 TDCi 180bhp Titanium
- steve_earwig
- Moderator
- Posts: 19813
- Joined: Thu Oct 04, 2007 6:09 pm
- Location: Jastrebarsko, Croatia http://www.jastrebarsko.hr/lokacija/
Re: What's the black box under the throttle pot?
Which one is yours - there's two, pre-mutlhex and multihex.
Unskilled meddling sin©e 2007
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