Handbrake Warning Light 1998 1999 2000 2001 CG Accord Coupe

[PTR200S]

 Nice explanation , Dave ! Sort of follows with the tech on what I was thinking 

However, still of the opinion that if the fluid level is only half way to full as stated the opportunity to check the pad wear level and for minor fluid leaks should not be ignored.

After all, the fluid level was full when it started life on the road and so any drop should be investigated and if nothing found the level should be topped up so that it can be monitored easily, waiting for a warning light to stay on is not really an option.

The fact the light is coming on due to an artificially lowered fluid level from contraction of the fluid is just enhanced if the level is already too low bearing in mind there is naff all fluid in reality in the reservoir, not like there is a couple of gallons in there 

 

[DeanoCoupe]

I have noticed that my light stays on now the weather is cold, so I am liking the theory on viscosity... Either way I need to do a fluid change 😀

[Lumpy]

I'm a bit confused and irritated now. Last week the 2 brake warning came on and have continued to. Fire engine and all lights are off. About 15 to 20 secs later, sometimes linger they come on. Pads are new. I have checked the level sender operation and it's fine. Also disconnected the sender and no difference. I've also fitted brand spankers lucas tail/brake bulbs. Spoiler is LED so nothing to chamge. I've not pulled multiplug off and refitted yet. What else can it be or where can I find how to stop this? Aaaaaaagh.

[Lumpy]

31 minutes ago, Lumpy said:

I'm a bit confused and irritated now. Last week the 2 brake warning came on and have continued to. Fire engine and all lights are off. About 15 to 20 secs later, sometimes linger they come on. Pads are new. I have checked the level sender operation and it's fine. Also disconnected the sender and no difference. I've also fitted brand spankers lucas tail/brake bulbs. Spoiler is LED so nothing to chamge. I've not pulled multiplug off and refitted yet. What else can it be or where can I find how to stop this? Aaaaaaagh.

Also. Handbrake switch seems to work fine as this causes the light to go on and off as normal. That's before both lights come on of course. After that it has no effect of course

[hughezee]

You say both warning lights, I assume you're referring to the warning to say a bulb is blown, so did you fit the dual filament bulbs 🤔 and it might be worth checking the earth connections below the rear n.s light. I had a niggle with mine a while ago and soldered the joins to the earth terminals to eliminate any future oxidation?  

[Lumpy]

2 hours ago, hughezee said:

You say both warning lights, I assume you're referring to the warning to say a bulb is blown, so did you fit the dual filament bulbs 🤔 and it might be worth checking the earth connections below the rear n.s light. I had a niggle with mine a while ago and soldered the joins to the earth terminals to eliminate any future oxidation?  

I can do that too, thanks, that's something I had't thought off. The lights shine good and bright but may be high resistance. I'll let you know.

 

And yes, the brake out light AND the low level' warning light come on together.

[Lumpy]

another search came up with this, does this sound feasible. It's only just started doing it The rear right headlight assembly has a black sensor box with a white square connector two screws hold it in, once you have the box out, using a knife to help remove the connector Now remove the PC board, which pops out very easily. On the passenger side, the module will have what looks like 3 coils, if it’s the passenger side, two for the driver side but they're not really coils. The driver side has only two, and the module is smaller in size. “Measure across them they should read open”, it’s a reed switch inside a coil, if current going to the light bulb passes through the coil the reed switch closes and opens. It made to be open until current passes through the coil. They put it inside the it feels the EMF of the current going to the light, beats me how it works my guess if your light comes on and goes off it could be the dirty connector issue too. Check each one the coils( really your checking the reed switch) that if read a dead short with an ohm meter, IT IS BAD You can maybe use a reed switch from an alarm sensor or what is used in the motor circuit of the 10 foot satellite dishes. YOU CAN NOT SEE THE REED SWITCH IT’S HIDDEN INSIDE THE BLACK PLASTIC OF THE COIL, YOU ONLY SE THE TWO WIRES FROM EACH END. My guess is they made this circuit to detect bad connections to brake bulbs, so you know they’re starting to die, and you can then say WTF, and check your bulbs and maybe clean them, so they won’t die, and you die when someone hits you

[hughezee]

The sensor unit is white and located in the same location as the earths, these rarely go wrong and even have swapped them just out of interest no change in the fault the topic linked below maybe of interest and just sorted the missing pictures out too...🙄

 

[Lumpy]

Update today, and it may be irrelevant but.... White box had some water in it and some of the PCB was a bit dull from it. I used a fibreglass pencil and cleaned it up a bit and resoldered some of the dull looking joints on the pins out. Popped it back in and lights on ALL the time, as opposed to coming on after a bit ☹️ so a change. Disconnected and lights off, but no brake lights of course. Boot mounted one works so that'll do until I can get a replacement oR get my electronics chap to have a close look. To me, it looks as if this could be the issue, due to water ingress, what do we think?

What part number or what do I look for? Ta in advance again.

I'll take some images later and post.

[PTR200S]

17 minutes ago, Lumpy said:

White box had some water in it 

Looks like you have found the problem then....  perhaps Stu can help out with a replacement....  Really could do with trying another one first to see if it resolves the problem... maybe this is just one part of the problem..

If it is the stop light sensor.... the Honda part number is 37540S82G01

Number 27 on the diagram.... perhaps you can identify it from the look of the part ?

[hughezee]

19 minutes ago, PTR200S said:

perhaps Stu can help out with a replacement.

I have a couple of units spare, message me your address and if you cover postage I will pop one in the post special delivery or standard post? 

[Lumpy]

7 hours ago, hughezee said:

I have a couple of units spare, message me your address and if you cover postage I will pop one in the post special delivery or standard post? 

message sent, most likely, and special delivery will be great. Let me know how you want funds transferred. Cheers very muchly.

[hughezee]

No probs just off to post it also included a radio adaptor cable and an ignition relay, just send back the old relay, a topic on the relay is linked below...

 

[Lumpy]

 

Doesn't look too bad now cleaned up a bit, not sure what, if anything, has popped. Electronics chap here explained how it works, and shunts, and stuff but he may as well have been discussing quantum physics to a child telling me

Oh and to finish with a bit of fun, I put my Style 32 alloys up against the wifes Alto, but may need some fettling to fit.

 

[Laird_Scooby]

On 12/10/2018 at 3:44 PM, Lumpy said:

I put my Style 32 alloys up against the wifes Alto, but may need some fettling to fit.

Fitting suggestion! 😛

As for the PCB, give it a clean with IPA (IsoPropyl Alcohol) and either leave it at an angle to run/dry off or blow it with compressed air. I might be wrong but that looks like a custom chip on it, the SIL package sitting upright but you may get away with cleaning it if it's only water causing the problem.

If it works, remove it again and spray it with lacquer to keep it dry in the future.

[Lumpy]

2 hours ago, Laird_Scooby said:

Fitting suggestion! 😛

As for the PCB, give it a clean with IPA (IsoPropyl Alcohol) and either leave it at an angle to run/dry off or blow it with compressed air. I might be wrong but that looks like a custom chip on it, the SIL package sitting upright but you may get away with cleaning it if it's only water causing the problem.

If it works, remove it again and spray it with lacquer to keep it dry in the future.

Well.... I cleaned it with IPA and gave the dull solder joints and corrosion between the tracks a light rub with a fibre glass pencil. I refitted it and instead of the lights coming on after 20 seconds, they stayed on from start up. I took it to work, looked under the big magnifier but that was a waste of time as I don't know what I'm looking for. I then used an Ambersil CB cleaner and brush to clean the board properly, used an air duster and then warmed it up to 30 deg C for 2 hours. I've not had a chance to try it yet but finger crossed. It was only water, and not that much but the solder joints were dull and furry,

[Laird_Scooby]

Sounds like you've done everything i would have done if i'd had the facilities - i gave the short version above as a DIY "best effort". If you work somewhere that has those facilities then it's a bonus! Who do you work for if you don't mind me asking?

[Lumpy]

I forgot to add I sill spray it with conformal coating if it works. I have a Paul that is an electronics geek but it's not good use of his time. I was interested with comments regarding the non-standard chip, I've not seen another one to compare.

I work for SMC Limited, www.smc-comms.com in darkest Chandlers Ford.

[Jon]

Forgive me if this is not relevant to your issue and the expert advice that you are getting but I had similar problems with my previous Coupe some years ago. I too purchased new dual filament bulbs both Halford's own brand and then Lucas. The problem persisted. Can't remember who told me the impedance window was very narrow and to only buy genuine Honda bulbs which cured the problem straight away. I have only bought Honda bulbs since and have had no bother.

[Laird_Scooby]

15 minutes ago, Jon said:

Forgive me if this is not relevant

It's very relevant Jon and thanks for the reminder! Besides the bulbs themselves, it'w worth making sure the holders and contacts are clean to minimise any resistance variation between them as well. Fibreglass pencils are good for that too!

Also the bulb contacts, a pair of jeans is just abrasive but smooth enough to polish the sides of the metal base and also the solder contact on the pins.

There is a similar system on my Volvo and the way it works is it has a coil in each leg of the circuit, between these two coils is a reed switch which is magnetically operated. The magnetic field produced by each coil is proportional to the current flowing in each leg and if those magnetic fields are equal, they cancel each other out resulting in no movement of the reed switch. If one bulb fails, or even has a slightly different resistance then the two magnetic fields won't balance so the reed switch operates.

This small white sensor box is an updated version of the same but uses shunt resistors to develop a very small voltage drop across them. Inside the box are voltage comparators, if the voltages are equal, nothing happens. If they're not, the warning lamp comes on.

As such, good quality bulbs from the same batch are a pre-requisite, renewed at the same time (if one bulb fails, replace both) to ensure the best chance of equal characteristics.

9 hours ago, Lumpy said:

I work for SMC Limited

I have very vague memories of them from the early 90s, handy place to work with problems like this!

9 hours ago, Lumpy said:

I was interested with comments regarding the non-standard chip, I've not seen another one to compare.

If you type the chip number into your search bar, you will hopefully find out what it is. I was going to but can't quite make it out on the side of the chip - camera angle/lighting etc makes it tricky to read or maybe it's just my monitor - or eyesight!

[Lumpy]

Well, a successful hour on the coupe. Managed to program the spare remote in and work out how to use the boot release button ☺️ just need to change the drivers door servo to make that work too.

I somewhat reluctantly plugged in the cleaned and dried white box, and reluctantly fired the engine up expecting the brake warning light to be on but no. Left for a few minutes and no warnings still. 20 mile road test with lights on and off, and no red warning lights. Well chuffed with that.

 

So tomorrows job, remove door card and fit new servo and hopefully not need the key to open the door. Thanks for all the help so far.

[Laird_Scooby]

Excellent progress!

[PTR200S]

Great news ! Fingers crossed it was just the "water in the box" problem😁 

Question is, how , and where, did the water come from?.. or is it condensation?

 

[hughezee]

Great result Mac, least you had the spare handy just in case 😊

[Lumpy]

29 minutes ago, PTR200S said:

Great news ! Fingers crossed it was just the "water in the box" problem😁 

Question is, how , and where, did the water come from?.. or is it condensation?

 

Maybe run down the inside from the water coming out of the left fog light on the bootlid where the bootlid wasn't fully raised, but only a guess. There wasn't a lot and it looked as it some had been there before as the solder was very dull in places. Who knows?