Altezza PnP board speed correction

[Brendon001]

Hi Guys

Just trying to work out how to get my speedo accurate (have facelift cluster with needle gauge and digital gauge). It was running fine same as gps speed with the factory j160 6spd setup but have now swapped to a r154 gearbox 5spd with jzx110 3 wire speed sensor. The speed sensor works fine and have been able to adjust the digital input frequency up to around 305hZ from 244hZ on DI3 and this now shows the same speed in the link ECU as a gps speed. However my dash still is out, ie at 50kph ecu speed dash shows around 58-60kph and at 100kph ecu speed dash shows around 115kph. 

The speedo out option appears on the ecu appears to be not used/ ever configured from factory so wondering if anyone knew if the speed gets sent via Can bean network etc to the dash or how I can fix this. 

 

Or does anyone know if the speedo signal goes to the dash and then out to the ECU last. SXe10 manual 3sge.  

 

Thanks

 

Brendon

[Adamw]

The speed signal comes into the ECU from the instrument cluster, the speed signal into the cluster is via multiplex (BEAN) from the BCM.  The ECU has no influence in what speed is displayed on the dash.

The easiest option would probably be a "speedo corrector" such as a SGI-5E to fudge the signal coming out of the VSS.  If the sensor is a hall effect type another option may be to connect the sensor direct to the ECU (instead of to BCM), then send a corrected signal out of the ECU to the BCM wire, but that sounds like more work.

[Brendon001]

Hi

 

Thanks for the reply. That confirms why i cant get i working on the dash correctly... i think i will just take the speed input into the dash and the speed out to the ecu and join together to get the VSS straight to the ecu. Then just use a spare aux out on the ecu to send back to the old VSS input on the dash. That way hopefully would work and only need one wire from the ECU to the dash then i presume once i configure the digital input i can configure the output to the dash etc. 

 

Cheers!

[Adamw]

As I mentioned in my post, that is only an option if the VSS sensor is a hall effect type (the BCM will expect a square wave signal), if it is a VR sensor it wont work as the BCM will expect a AC/Sine wave signal.  The ECU can only generate a square wave (The SGI can generate either).  I think the R154 sensor is a hall effect but I have never touched one personally.

[wastegate]

Have to correct you a little here Adam.

The body computer doesn't handle SPD. In manual cars it comes from the transmission directly to the cluster. Then to the ECU.

In Auto cars, it comes from the ABS/TRC computer to the Cluster (->A12), then to the ECU (A13->).

Instead of using the signal from the gearbox, rewire it to be the same as Auto trans cars. Uses signal from ABS/TRC (Skid Control) computer.

https://www.my.is/threads/how-to-abs-to-speedo-rewire-for-v160-swapped-iss-02-5spds.412759/

There is a SPD output from the cluster that will go back to the ECU so the Link will have SPD then too.

SPD isn't on the Bean network.

 

 

 

[Brendon001]

That makes sense as to why my pinout diagram for the cluster specifically references the speed input as 6MT etc. That seems like an easier way to sort it. Am i correct in saying that the speedo would not be out again if my gearing changed or my final drive changed as it would then be off the actual wheel speed. I would take it that rim and tyre size would still affect it slightly. 

[wastegate]

Correct, comes from the ABS wheel speed sensors, only tyre circumference would effect it.

[Brendon001]

So tried this now have no speed at all. Put a  spare pin in the abs module plug as per the instructions and cut the existing speed input to the cluster. Cant seem to get a signal from that ABS pin that is stated. Wondering if its differnet between the is300 US LHD models and ours altezza RHD. Trying to find a pin out for the auto altezza abs module if you know of one

[Brendon001]

Update; Have joined the existing r154 gearbox speed sensor straight through to DI3 input and got that reading correctly in the ECU based off GPS speed. Then i have wired and configured an AUX out to the speedo orginal input on the cluster. Set up key sweep and max HZ based of what the key sweep gets to (180kph) and now have a multiplier of 0.87 and the speedo is reading correct at all speeds.

 

Final question is at very slow speeds (1-13kph) my gauge and electeonic gauge jump from 0kph to 13kph (any speed under that shows 13kph until i stop and goes 0kph.). Is this something to do with the offset Hz value? Current set at 0 and tried small Hz values (5,10 etc) but makes the problem worse( goes from 13kph minimum to 20kph minimum etc) Is it possible to put negative Hz numbers here and then redo the multiplier?? 

 

Almost sorted! 

 

Brendon

[Brendon001]

Anyone have ideas on my last post re speedo jumping from 0kph to 13kph?

[Adamw]

The minimum frequency an aux output can do is 10Hz, below that it will drop to zero.