M0559 Road Speed Sensor Box - faulty

[Colin RedGriff]

Hi

I think my road speed sensor box is faulty. I drove the car with rovergauge connected and the road speed stayed at zero, however my Speedo is working fine so I know the bit at the diff end works. I also got the fault code for the road speed sensor.

I've got the dash out at the moment and had a look in the box but I couldn;t see anything obviously wrong all the compnents looked visually ok and none of the wires were loose.

It's a 96 500 with T5 box.

TVR Parts want £100 for a replacement so was wondering if anyone knew if there were any tests or possible repairs I could do on it. Have basic soldering skills and a test meter but not oscilloscope. Does anyone have one they've removed which they would want to sell me?

Thanks

[stevesprint]

Colin

I've got a spare M0559 you're welcome to try, it came from a Griff 500 after an ECU upgrade. I'll bring it to the next Berkshire meeting or pm me your address and I'll post it.

Steve

[Colin RedGriff]

Hi Steve

Thanks for the offer. Once I've got the new dash back in and the car is mobile again I'm going to check it again, I've been round the joints and given them all a bit of a clean which might help. I'll drop you a PM if I still have a problem so I can test it with yours.

Colin

[blitzracing]

Ive seen some very poor soldering on the socket thats soldered to the PCB, where the lead has not flowed onto the connector correctly and left a void. Theres not much to the electronics- just a tacho chip that reads the input pulse stream and then fires a timer chip that produces the fixed speed signal you see of around 40 mph, a few £ of electronics if that. I dont mind having a look at it for you if Steves one fixes your fault.

[Colin RedGriff]

Thanks Mark

Don't know if mine is different but the socket is attached to the case and connected to the PCB with short wires rather than attached directly to the PCB.

I'll get my meter out and check some resistances but I may well take you up on your offer.

[stevesprint]

Colin RedGriff said:

Thanks Mark

Don't know if mine is different but the socket is attached to the case and connected to the PCB with short wires rather than attached directly to the PCB.

I'll get my meter out and check some resistances but I may well take you up on your offer.

Colin, You mean like this

[Colin RedGriff]

Yes just like that.

[blitzracing]

The one I saw failed had the connector direct on to the PCB.