Orange engine light and speedo' not working

[Wisey]

Hi all, just been out for a short journey in my 2007 Alphard 2.4G and noticed two things, the orange engine light is on and the speedo' has stopped working, odometer is OK. It still runs well and I've just ordered an Ancel JP700 which should be with tomorrow to try and identify the fault but meanwhile, has anybody out there had a similar problem or could offer an explanation? Could these two events be connected? Long journey ahead at the weekend and so keen to identify and resolve the problem.

Thanks, Alan

[MonsterS]

Could be the conversion chip on the back of the speedo causing issues.

[Wisey]

1 hour ago, MonsterS said:

Could be the conversion chip on the back of the speedo causing issues.

Thanks Alex, could be, especially since both faults occurred simultaneously although I wouldn't have initially thought they were connected. Any advice or tutorials on how to expose and fix welcomed.

[Rojie]

7 minutes ago, Wisey said:

Thanks Alex, could be, especially since both faults occurred simultaneously although I wouldn't have initially thought they were connected. Any advice or tutorials on how to expose and fix welcomed.

 

Try Youtube.

 

Cause is often a dry joint, or no solder !

[Wisey]

1 hour ago, Rojie said:

 

Try Youtube.

 

Cause is often a dry joint, or no solder !

Thanks Roger, had a look but couldn't find anything specific for an Alphard. I seem to recall something similar on the Forum previously but can't locate it?

[Wisey]

2 hours ago, Wisey said:

Thanks Roger, had a look but couldn't find anything specific for an Alphard. I seem to recall something similar on the Forum previously but can't locate it?

Had a look at the Speedo’ and it seems to have an MPH disc mod rather than a chip, probably why odometer is still in Km’s. Fault could be at the gearbox end?

[Picasso]

You have 2 speed sensors on the gear box both the same part no. If you give me a reg no. I will attach a drawing for you 

[Wisey]

12 minutes ago, Picasso said:

You have 2 speed sensors on the gear box both the same part no. If you give me a reg no. I will attach a drawing for you 

Ah, ok, it’s LU02 ZEN, thanks!

[Picasso]

Oe no. Is.  8941324010. 2 fitted to transmission both same put part no. In to Ebay very cheap 

[Wisey]

Thank you Lee, I'll get a couple ordered.

[Geralt]

On 6/8/2023 at 11:35 AM, Wisey said:

the speedo' has stopped working, odometer is OK.

By odometer OK, you mean it still increments?

[Wisey]

20 hours ago, Picasso said:

You have 2 speed sensors on the gear box both the same part no. If you give me a reg no. I will attach a drawing for you 

Yes, it still records the number of Km’s travelled but the Speedo’ itself doesn’t operate, needle stays at zero MPH. 

[Geralt]

6 minutes ago, Wisey said:

Yes, it still records the number of Km’s travelled but the Speedo’ itself doesn’t operate, needle stays at zero MPH. 

In that case I doubt there is a problem with the incoming vehicle speed signal. Usually a single signal is used to update both speedo and odometer but I'm not certain of that so am prepared to be corrected. It could be that the instrument cluster speedo motor is broken. Also if it runs well and changes gear at the right times that too suggests the gearbox speed sensors are OK in my view.

 

Has your OBD reader arrived?

[Wisey]

Hi Geralt, thanks for the information which certainly makes sense. The OBD reader has just arrived and so I'll give it a go and see what it says. Never used one before but I'll give it a go and be in touch again later.

Cheers, Alan

[Wisey]

So, I've connected it up and showing "P0500, Vehicle Speed Sensor" which confirms previous theories. Question now is, we're going to Liverpool and back this weekend and whilst I'm not particularly worried about no speedo', will anything else be affected (gear changing?) etc in time?

[Geralt]

If it drives OK I should think that you won't do any damage.

 

BTW, is your vehicle 2002 or 2007?

 

If the former then it's like mine. I can see in the wiring diagram that the ABS unit sends a speed signal (SI) to instrument pack. The instrument pack then processes and sends out a modified speed signal (SPS+) to other ECUs like Engine Management, Body Control, sat nav etc. It's the engine management ECU that's reporting P0500 probably hence the MIL on.

 

I still don't think the issue is gearbox sensors. It's more likely that it's ABS but then  I don't know why you're not seeing a brake fault light on the dash in that case.

Edited June 9, 2023 by Geralt

[Wisey]

No. it's a 2007 with my wife's registration number fitted. I think we'll head off early doors tomorrow, should be OK and my RAC membership is up to date just in case.....

Thanks for your help and I'll get it sorted next week. See you on 2nd July at Gaydon, maybe?

[Geralt]

1 minute ago, Wisey said:

No. it's a 2007 with my wife's registration number fitted. I think we'll head off early doors tomorrow, should be OK and my RAC membership is up to date just in case.....

Thanks for your help and I'll get it sorted next week. See you on 2nd July at Gaydon, maybe?

Safe trip. Yes we're pencilled in the for 2 but not committed yet.

[Geralt]

I did a bit more digging. Further to my previous post, I think this confirms the signal route for vehicle speed in the Alphard too:

 

https://www.toyaris4.com/toyota_yaris_vehicle_speed_sensor_a_no_signal_p050031_-1132.html

 

There are four pulses per rotation of a wheel on the SPS+ signal.

 

The circuit detail broadly matches the Alphard Gen 1 wiring diagram too:

The only contradictory evidence is the fact your odo keeps incrementing. I'm baffled as to how!

[Wisey]

Speedo not working, update:

Changed both speed sensors today but speedo still not working and engine management light still appears after a few seconds and the same fault code, P0500 given. 
Also, engine idling very slow, almost stalling and gear changing seems a bit erratic but still drivable. 
Obviously I’ve made the situation worse, any clues as to how or why?

 I’m still planning to be at Gaydon meeting on Sunday and hopefully get some clues as to why and how to fix from others there. 
Cheers, Alan
 

[Geralt]

5 minutes ago, Wisey said:

Changed both speed sensors

You mean the transmission shaft speed sensors?

[Wisey]

I guess so, both located below the battery tray, part number 8941324010.

 

[Geralt]

Sorry to hear you're still having trouble but I think changing those sensors was never going to solve the issue. As previously mentioned, I'm fairly sure vehicle speed comes from ABS ECU via instrument cluster.

If I were you I would be getting a basic oscilloscope and tapping the SI and SPS+ signals on the back of the instrument cluster to check that you have the 4 pulse signals while somebody else drives the van. If one of them is missing then that indicates the source of the issue.

[Wisey]

Being a mechanical engineer that sounds far too technical for me to undertake but I do see your point about the ABS ECU, is this easy/ inexpensive to change?

Maybe I should also remove the speedo cluster to see if something has simply come adrift?

[Geralt]

1 hour ago, Wisey said:

is this easy/ inexpensive to change?

I think access to ABS is relatively easy so changing it might not be too tricky. Bleeding the system might be complicated but I think any garage could do that. But I think that is a bridge to be crossed if you come to it. It might be the instrument cluster.

1 hour ago, Wisey said:

Maybe I should also remove the speedo cluster to see if something has simply come adrift?

Yes definitely do that first. Problem might go away after re-seating the connectors.