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heat light (V6)

Posted: Sun Jul 25, 2010 10:52 am
by Alan350
The heat light on my V6 came on and has stayed on after a problem with oil leaking from the rocker cover onto the plugs and the engine overheating. The rocker cover gaskets have been replaced and the engine is running fine. The light is still on, I have tried resetting the fault codes as described in the bongo fury fact sheets but no luck. Has anybody come across this problem or does anyone have any ideas.

Alan350

Re: heat light (V6)

Posted: Sun Jul 25, 2010 11:58 am
by cheffy34
Once the sensor is dead its dead, do a search on it i have posted plenty on it, it tells you that your cat pipe has overheated for some reason possibly due to missfire, raw fuel entering the pipe, upto you if you want to replace or not :roll: if you disconnect the sensor at the plug and cable tie it out of the way the dash light will behave normally :wink: the heat sensor is not ecu controlled but could also be tripped due to long term lambda probs and overfuelling, I just disconnected mine and left it, it doesn't controll fuelling :!: :!: not worth the £120 odd squids


Dar

Re: heat light (V6)

Posted: Mon Jul 26, 2010 11:47 am
by Alan350
What a result, I disconnected the sensor, which was quite easy to reach, and the heat light is now off.
many thanks for your help.
Alan350

Re: heat light (V6)

Posted: Mon Jul 26, 2010 6:13 pm
by wishmaster
cheffy34 wrote:Once the sensor is dead its dead, do a search on it i have posted plenty on it, it tells you that your cat pipe has overheated for some reason possibly due to missfire, raw fuel entering the pipe, upto you if you want to replace or not :roll: if you disconnect the sensor at the plug and cable tie it out of the way the dash light will behave normally :wink: the heat sensor is not ecu controlled but could also be tripped due to long term lambda probs and overfuelling, I just disconnected mine and left it, it doesn't controll fuelling :!: :!: not worth the £120 odd squids


Dar
After doing this would it have an effect when it comes to MOT/emmisions :?:

Izzy

Re: heat light (V6)

Posted: Mon Jul 26, 2010 9:23 pm
by cheffy34
wishmaster wrote:
cheffy34 wrote:Once the sensor is dead its dead, do a search on it i have posted plenty on it, it tells you that your cat pipe has overheated for some reason possibly due to missfire, raw fuel entering the pipe, upto you if you want to replace or not :roll: if you disconnect the sensor at the plug and cable tie it out of the way the dash light will behave normally :wink: the heat sensor is not ecu controlled but could also be tripped due to long term lambda probs and overfuelling, I just disconnected mine and left it, it doesn't controll fuelling :!: :!: not worth the £120 odd squids


Dar
After doing this would it have an effect when it comes to MOT/emmisions :?:

Izzy

Hasn't on mine for the last 3 years :D like i said not linked to fueling lots of early imports have the same sensor in the cat pipe :wink: i think you will find it for the jap market :wink:

Re: heat light (V6)

Posted: Mon Jul 15, 2013 11:43 am
by longwori
Hi guys, sorry to bump up an old topic but I had the same problem with an oil leak and now my Heat light is stuck on. The MOT is due soon so I would like to disconnect the sensor that is responsible for the indicator light however when I look underneath, I see two possible culprits. One closer to the engine with a visible plug and another forther down the vehicle.

Any ideas which is the one to disconnect?

I dont want to accidently disconnect the Lambda sensor rather than the heat sensor.

Thanks chaps.

Ian

Re: heat light (V6)

Posted: Mon Jul 15, 2013 8:41 pm
by longwori
I took this picture to help with clarifying which wire......

Is it cable A or the pretty new looking cable B that I unplug to get rid of the "Heat" light off the dash?

Image

Thanks,

Ian

Re: heat light (V6)

Posted: Mon Jul 15, 2013 11:17 pm
by Simon Jones
A is your lambda sensor, therefore B must be the one you should try unplugging. Note: the bulb may light up when the circuit is high resistance so disconnecting it may not work. Interestingly, I don't have one of those on my 2002 V6.

Now, I'll probably get shouted at :), but if I were you, I'd remove the bulb if you cant readily fix it. It's not a safety feature like ABS or airbags, so won't be a light that is specifically being looked for during an MOT. When I had my instrument panel out the other week, I found there was no bulb holder in the heat light socket. On closer inspection, there is no sign it was ever fitted with one as the PCB tracks were totally unmarked: there would have been a track scored into them if a bulb holder had ever been inserted. I even stuck a bulb in there and it did not light up when the ignition is switched on. My conclusion is that is the lack of the bulb, no wiring under the floor and no sensor on the exhaust (which is genuine Mazda) means this was not fitted to the later models.

If anyone has more info on what this sensor does, I'd be interested to find out.

Re: heat light (V6)

Posted: Tue Jul 16, 2013 12:17 am
by mikeWalsall
Just looked at a recent pic; of the rear of my Speedo panel .. and I have to admit comparing the printed circuit board bulb locations, it looks like my 1998 never had a cat. over heating bulb in.. where as it is obvious that the ABS once had a bulb / holder in ..

Image

Re: heat light (V6)

Posted: Tue Jul 16, 2013 2:39 pm
by longwori
Hi Simon, thanks for directing me to the correct lead. I will try disconnecting it later and see what happens.