speedo failed

[+robster+]

anyone had this problem?

speedo failed abs and brake lights on all the time ( on dash). no codes via elm327 but this is a cheapo just really for engine emmisions systems

car drives fine exept a slight bit chuggy taking off from low revs. , and presumably no function of abs but don't really want to test the theory

looking at car ive came to conclusion the abs module has gone defective.

it looks like this is related to speed sensor/abs sensors working the same feedback to abs module for

1. abs function

2.speedo feedback to dash.

3 maybey ecu feedback to fuel maps for acceleration to actual speed calculations?

I have removed the plug from abs module with no change , further lending to my suspicions.

all fuses relays and wiring check out ok as far as I can trace.

abs sensor readings almost exact same left for right so 2 are not gonna fail simultaneously?

I'm not one for doing this usually but ive just ordered a salvage abs module for test/fix hopefully ( eBay )

providing the module to arrive is good, at £19.99 is the cheapest and less time consuming option to me just now

is this common?

has steam cleaning engine bay 2 days ago been fatal? ( scotch mist and all that) lol

anyone had this fault?

 

[+robster+]

further info for anyone who has same symptoms

ive ruled out some more things by coming across a diagnostic fault tree for my model

power and grounds to abs module ok means fuses and wiring before this point are fine

cg and tc terminals of dlc3 connector bridged to show abs flash code = no codes displayed ( probably due to dead module)

speedo works via signal pulse from abs module blue and white wire

quote;  Check continuity between the terminal S1–35 (SP1)/S2–23 (SP1) of the skid control ECU and the terminal
C11–19 of the combination meter connector ; end quote

this is ok so this part of wiring from abs ecu to dash is ok

check dash abs light function

quote; Using service wire, connect terminals WA and GND of the
skid control ECU harness side connector.
(c) Turn the ignition switch ON.
OK:
ABS warning light goes off. ; end quote

light went out with this test

this linking of wire is ( one of many) of what the abs ecu is meant to enable when the system does its watchdog and sees everything ok

this proves abs ecu isn't doing it and this part of my dash function is fine

so I need to wait on part arriving on Tuesday to hopefully sort this problem.

I'm still using driveable car,

engine ecu has adaptive learning very quickly to not "kangaroo" at low revs anymore.

sat nav used as speedo

I will do a tear down of old part next week see if any water ingress has occured

 

one question I don't know as I'm not a motor trade mechanic

WILL THE NEW ABS MODULE NEED CODED TO VEHICLE ?

or is it a plug and play thanks

[Konrad C]

Hi Robbie, I know the you are working on a later car to my old Mk1, but when the ABS failed the speedo was working fine. The ABS module was dead - no codes! I used the jumper wire trick, but the ABS light just stayed on.

I changed the ABS module only with one from a scrapped car and everything returned to normal. No need to code the unit to the car.

I thought that the ABS control module got the vehicle speed from another module? The ABS module checks the individual wheel speed. The vehicle speed module also shares the info to the speedo and any items. It seems that in your car, the ABS module gets sends speed info to speedo, from what you stated!

I hope the ABS module is the correct fix. 

[+robster+]

I have abs with ibd only on diesel engine model

No  tsc or vsc

Im probably lucky with being the simplest form with less to go wrong.

Looking at the toyota diagrams and following the options of my car specifics.  it shows direct link blue and white wire from abs module to dash internal speedo cpu.

Also the checks asked and verified this system while checking.

There is other options as said like traction control etc where there will be extra wiring and modules but never got into the nitty gritty of another system.

But to conclude

I recueved my salvage part today when i got home from work.

For testing purposes only i Piggy backed it to car so to speak by plugging loom into it and cable tieing salvege part to old part.

Shut bonnet and tied it out.

Thank goodness

Speedo working and abs lights off.

I will fit one of these weekends when i get all wheels off for cleaning and to aid bleeding

It is a Bosch unit on close inspection.

Wonder if its toyota specific or generic?

Oh yeah and it is plug and play ta

[Konrad C]

I think the ABS units are generic. Yours looks like a Bosh ABS 8.0. 

I just changed the black box. Saved on bleeding the brakes. But if the ABS pump is faulty, then all of it needs to be changed. 

[+robster+]

Good to know and will try splitting electrics from pump and valve.

Will save bleeding.

 

Just wasnt sure if it was a sealed pressed soldered type assembly if i opened it up and ended up ruining it

 

Ta

[+robster+]

Ok excuse the post by phone.

Ill keep it short and sweet

See pics of original unit i found a crack in letting in the elements.

I cleaned mechanical part with brake cleaner and smeared a little vaseline on sealing rubber on fitting

I changed over electric part only in place with success

Various pics of old and donor parts through fitting stages. Took about20 mins tops

I never had an e5 socket but a 4mm socket was perfect fit.

Sorry about the mishmash of pics

First 4 are cracked original then removed showing ingress corrosion

Then next is new fitted to original cleaned valve body in place

Last is whats left of donor showing very slight ingress on this part also.

 

A thousand thank yous konrad  for pointing me into renewing electrical control only.

Not has it saved me time . Hassle and possible contamination from the donor part as brake pipes were hack sawed off. Working on hydraulics i know the little things can stick valves and valve seats

But i learnt a lot about a system that has never gave me any bother in the past apart from the odd wheel speed sensor and is taken for granted but is a quite genious set up of varying  magnetic controlled valve control to each corner , adjusting under various circumstances