That dreaded speedo problem!
That dreaded speedo problem!
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Discussion

Lucozade

Original Poster:

2,574 posts

308 months

Saturday 10th March 2012
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Washed the car today and now the speedo has stopped working.

It usually "self repairs" after a little drive but this time no luck.

I've had a look at what I presume is the sensor, attached to the drivers side wheel. It basically looks like a bolt with a cable coming out of it.

Is this an easy swapout for a non mechanical type like myself. I've managed to get the bolt out and clean it up but it's still not working.

From what I can see it looks like it is hardwired to the cable and that the cable runs into the bulkhead, but I can't locate it inside the car.

Zoobeef

6,004 posts

187 months

Saturday 10th March 2012
quotequote all
Give the teeth on the hub a clean/sand. How close have you got the sensor to them?

Lucozade

Original Poster:

2,574 posts

308 months

Saturday 10th March 2012
quotequote all
Zoobeef said:
Give the teeth on the hub a clean/sand. How close have you got the sensor to them?
The teeth look "rusty" that's for sure. I've moved the sensor as close as I can get away with without it touching. How far away should it be?

Zoobeef

6,004 posts

187 months

Saturday 10th March 2012
quotequote all
Not to sure. Mines pretty close. Mine did the thing where it said i was doing 80mph while doing 10mph. A sand and it fixed it. Would be good to know where the connector is to replace the whole thing though

Jim O.

486 posts

226 months

Saturday 10th March 2012
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On the US cars, the connector is next to the fusebox in the passenger footwell. The sensor that we use has an led on the back of it(next to the cable) - with the ignition key in the "on" position and the immobilizer disarmed, the led turns on when the sensor is triggered. Makes it easy to check the sensor by gently moving a piece of ferrous metal (I use the tip of a screwdriver) across the tip of the sensor. If the led blinks, the sensor is working. After checking the sensor, jack up the corner and spin the wheel. If the led doesn't blink, then you know it isn't picking up the slotted wheel - clean up the wheel and move the sensor closer to the hub.

Lucozade

Original Poster:

2,574 posts

308 months

Sunday 11th March 2012
quotequote all
Jim O. said:
On the US cars, the connector is next to the fusebox in the passenger footwell. The sensor that we use has an led on the back of it(next to the cable) - with the ignition key in the "on" position and the immobilizer disarmed, the led turns on when the sensor is triggered. Makes it easy to check the sensor by gently moving a piece of ferrous metal (I use the tip of a screwdriver) across the tip of the sensor. If the led blinks, the sensor is working. After checking the sensor, jack up the corner and spin the wheel. If the led doesn't blink, then you know it isn't picking up the slotted wheel - clean up the wheel and move the sensor closer to the hub.
Thanks Jim O and Zoobeef speedo working again.

I did the sanding and then using the method above managed to get the LED lighting up. It had to be pretty darn close though. Certainly handy having the LED on the end of the bolt!

AMG Merc

11,955 posts

282 months

Sunday 11th March 2012
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If you've managed to get it out then you're half way there. Pop along to your dealer and have them connect a new sensor (part is c. £75 if needed) off the hub and spin the wheel to see if yours is shot. Mine lasted years with getting wet and stopping working - drying out - working again... but it finally gave up the ghost and I needed a new sensor.