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TimoL

Batt voltage reading not changing

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So here's the full story,

Few days ago I started having problems with the car running really rich. First I thought it has something to do with MAP sensor or FPR but I couldn't find any fault.

Then I went to check ECU readings and I noticed battery voltage was stuck to around 11.5V. This would explain why the car was running too rich because the ECU adds too much injector dead time to PW. I'm 100% sure the alternator or battery is not at fault here. There was zero change in the voltage reading when I applied full electrical load on the system vs. load at all. 

 

This has been happening for a few days now. It's not the same reading it gets stuck to.  And it's always on cold starts, but I haven't done that many warm starts.

If I shut the engine down after a while and restart, the voltage reading is working again.

I've attached a log from this morning when I started the engine and shut down a couple of times. After I saved the log and started the engine again the voltage reading started working.

 

Changes I've lately to tune is to enable internal logging. The voltage reading got stuck again tonight. When I disabled the internal logging and saved the settings it started working right away, no restart was needed. I'm not sure if this issue has something to do with the logging or if the settings save triggered this fixing effect.

Any thoughts? I can provide more logs or do testing if needed. But for now I've turned of the internal logging to see if it helps.

-Timo

battvolt_starts.zip currentConfig.pclr

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I would use a volt meter to measure the battery voltage (at the battery terminals) first.  This should be around 12 V with the engine off and no electrical loads.  Then start the engine and check that it goes up to around 14.3 V (as part of your log shows).  This will narrow down where the problem is very quickly.  

Hope that helps...

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Batt voltage wasn't logged in that file, so that's not much help.

Try doing a PC Log, it captures everything.

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Dave, I initially thought that, but it is logged.  See below... It's a bit strange though, if you type Batt in the parameter list, it doesn't appear as you'd expect!  However, if you click on Batt Voltage, it's there!  I can't explain that.......

 

image.thumb.png.76c632a35e1cdbad86e42e422a0d92ea.png

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Hi Timo,

We have had this reported by a couple of users now, so we believe it is a bug.  We havent been able to reproduce it in house yet last time I heard so I will pass your log on to engineering so they have more info to help find the problem.

 

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Hello,

I've been rather busy with my work so I didn't check this thread regularly. Thanks for all the replies.

I checked the battery voltage one morning and it was about 14.5V after cold start, engine running. The ECU was showing about 12V.

I have one 20 sec PC log that to took after about 20km drive. I tried various electrical loads by turning the lights and blower on or off. No change in reported voltage.I believe the reported voltage was wrong during the whole drive, it was running very rich whenever I had to stop or drive at very light loads.

I also noticed that I can't use the search function for the battery voltage.

 

-Timo

batt.llg

23 minutes ago, Adamw said:

Hi Timo,

We have had this reported by a couple of users now, so we believe it is a bug.  We havent been able to reproduce it in house yet last time I heard so I will pass your log on to engineering so they have more info to help find the problem.

 

The ECU config file I posted earlier contains the settings that caused this issue. Maybe they can test using it? Anything else I can do to help?

No problems since I turned off the logging, but I think it's a bit too early to tell for sure.

-Timo

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