V70 automatic gearbox issue

[virtually done]

Hello to you all. First post here on the forum and new to Volvo.

Recently purchased a 1999 V70 2.5T petrol automatic. I have to say I absolutely love the way it drives and wish I'd bought a Volvo years ago!

It does, however, have a problem with the gearbox. In 'D' the TRACS, engine management and ABS lights all stay illuminated. If 'L' is selected the ARROW on dashboard will flash persistently, as well as the previously mentioned lights staying on. The gearbox itself feels fine although it will clunk, quite heavily I think, when moving between gears with no throttle. Whilst on the move it pulls well and accelerates cleanly, well untill today. The BRAKE CIRCUIT FAILURE (exclamation) light came on (although the brakes worked ok), the speedo failed and acceleration was sluggish with hunting between gears.

I was aware of a gearbox problem when I got it, it had been to a garage that diagnosed a fault with the gearbox speed sensor (cpc?), although the part wasn't available when I collected the car.

I have had a look at similar topics on the forum. I have tried moving the gear lever between P & L approx 20 times, and this seemed to work for about 80 miles then re-appeared. Any advice on this matter would be very much appreciated, automatic gearboxes are new to me and this is the only glitch in an otherwise fantastic car. I'm considering ordering the gearbox speed sensor or taking the car in to a dealer to have the fault codes read, do either of these sound like a good course of action?

Thanks in advance.

[st5ve]

Have the codes read it does sound like the speed sensor has gone, when you bought the car did the place you bought it from not agree to replace the sensor or sort the problem out for you?

[grass hopper]

could be a faulty ABS module,especially with the abs and speedo gets a reading of the module.

[virtually done]

Thanks St5ve.

I bought the car from a good friend at a very good price, the wrong part had been sent when I picked up the car a few days ago. He'd had it diagnosed as the speed sensor which seemed to make sense, just a bit concerned about the speedo failing too. Would the pickup for this also be in the gearbox? I've got to say I love this car, It's not my first but I'm finding many reasons just to drive it!

[st5ve]

I am fairly sure if the speedo sensor is knackerd it will impact on the abs system. The auto transmision will not know what gear to be in due to not knowing speed of vehicle hence the box searching for a gear. Your speedo will not work as the sensor is faulty.

On the 850 the sensor is located on the rear of the transmission behind the right hand drive shaft, its an easy job to replace. I think its in the same location on the V70.

[grass hopper]

I think the sensor on the gearbox monitors only the torque converter speed,but I could be wrong.

the speedo only gets a reading from all 4 ABS wheel sensors which is transmitted to the ABS module and the speedo gets the reading from this module.

had a few were all these faults apear and the ABS module was faulty,also usually when this happens the trip readings can disappear on the clocks also.

if the ABS module fails the car will go into limp home mode as the car/gearbox etc has no idea of road speed.

if the car fails again worth checking to see if communication can be achieved with the ABS module.

[virtually done]

Thank you gents.

I will take the car to my local dealer and have them run a check. It seems to point towards speed sensor, judging by previous diagnosis, but abs module sounds feasable too. Either way your posts have helped to ease my mind, looking forward to getting it sorted and enjoying the car fully.

Thanks again.