7 replies to this topic

[Swiftyds]

No ABS light coming on (does checks when ignition on then goes out) - speedo was intermittent to start now nothing at all.

Checked resistance of the four ABS sensors at the ABS ECU plug and three are 1.407k but the rear right (speedo sensor) is 1.394k.

 

Didn’t think the slightly lower resistance of the rear right wheel sensor would be enough to indicate a problem with that and as I said no ABS light is coming on. I’ve even gone as far as to swapping the ABS ECU control unit in case there is something up with how that is processing the signal from the right rear sensor and converting it to the signal for the dash, but that made no difference.

 

Checked what’s on the OBD2 port and no speed signal there at all. OPCOM 2 not showing any faults either.

 

Sort of points to a wiring problem between the ABS ECU plug and dash or the dash itself.

 

Does anyone know if the speed signal is routed through the dash before it gets to the OBD2 port?

 

[hairy]

Circuit diagrams are on FB:  https://www.facebook...54170462093894/

[Swiftyds]

Thanks - can see now where the wire from Pin 3 output of ABS ECU splits to speedo, ECU and radio so if it’s wiring related to that it must be before it splits given there’s nothing on speedo/stack nor radio nor OBD2 port.

Can I ask if anyone thinks the lower resistance on the right rear ABS sensor could be an issue even though the ABS light isn’t coming on?

[Swiftyds]

Just realised the sensor that has different resistance reading isn’t the speedo sensor - that’s on the NSR so don’t think it’s that.

[Swiftyds]

Looked at this again today - definitely no speed signal reaching the ECU and as I’ve already swapped out the ABS ECU with no affect then I can only think it’s a wiring or connector issue.

Looking at the wiring diagrams I’ve been pointed to seems to show the pin 3 output from the ABS ECU splits to go to radio, speedo and engine ECU but as both ECU and speedo aren’t receiving the signal then the issue is either before the split / branch in the loom or the speed signal does indeed go via the ECU to the stack speedo unit.

Will look at continuity testing the wiring in the loom over the next couple of days and also look at the two connectors behind the expansion bottle in the engine bay in case it’s just a bad connector. I’d previously swapped out fuse 8 as understood others have had similar problems and that had been the cause.

Oddly the ECU and ABS are both showing no stored faults when I look at them with OPCOM.

Edited by Swiftyds, 27 April 2021 - 05:44 PM.

[gibbie]

Hi there

did you ever get this sorted?

I have a similar problem with my VX!

So hoping you have some words of wisdom.

kind Regards

Paul

[oblomov]

Hi there

did you ever get this sorted?

I have a similar problem with my VX!

So hoping you have some words of wisdom.

kind Regards

Paul

Have you tried the speedo re-set?

1. Unlock car

2. open door

3. press and hold odometer reset button.

4. turn on ignition while still holding the odometer reset button.

[Ivor]

Still in 2021, when do we roll to 2022?

Edited by Ivor, Yesterday, 04:27 AM.