Hold light flashing and speedo not working

[vjw65]

Hi. New Bongo owner here. All has been fine with my N reg 2.5 diesel auto so far, until yesterday when driving along noticed that the speedo was not working and then that the hold light was flashing. This seemed to remedy itself after a while. I will be going out in it again tonight to see if happens again, but if it does not, should I be concerned? What would anyone suggest that I look at first if the problem persists? I am guessing that the two problems happening at the same time are connected...?! any info / help very gratefully received

[g8dhe]

Normally a Sensor problem, the sensor feeds the speedo and then the ECU and if it fails then the auto transmission etc get upset as they don't know what is going on! The flashing HOLD light is the transmission computers way of saying FAULT!! Often the problem can also be a small chip that is added to convert the speedo from KmH to MpH if so its fitted behind the display using 4 wires and is well known for failing.

[vjw65]

Thanks Geoff. I will get the chip looked at then for peace of mind. Is this something that can be done without taking it to a specialist? I was a bit worried that something was going wrong with my auto gear box. Vanessa

[g8dhe]

It doesn't need to be a Bongo specialist but I suspect a lot of garages might turn up there nose due to ignorance! Most people end up dumping the chip and adding a replacement scale to the speedo however it leaves the odometer reading in Kms rather than miles.