Fuel Gauges in Aussie LS2s

I have noticed issues with fuel gauges in Aussie LS2s. They may have the same operating system ute to sedan - but the gauge can indicate wrong after a tune. It can either stay up high too long or say that its empty very quickly when it still have plenty.

I am wondering about the cause and also the way to fix it.
Both issues have occurred after a base tune was used rather than a remodelled tune that was read from the actual car.

Quote:

---

Originally Posted by oztracktuning

I have noticed issues with fuel gauges in Aussie LS2s. They may have the same operating system ute to sedan - but the gauge can indicate wrong after a tune. It can either stay up high too long or say that its empty very quickly when it still have plenty.

I am wondering about the cause and also the way to fix it.
Both issues have occurred after a base tune was used rather than a remodelled tune that was read from the actual car.

---

ALWAYS , I REPEAT ALWAYS , tune the customers car using their base cal, dont wack a base tune in off the net or sucked out of another car as there are lots of differences betwen the cals , the VZ onwards has fuel guage stuff in the cal that you dont have access too that is individual to each car

Quote:

---

Originally Posted by oztracktuning

I have noticed issues with fuel gauges in Aussie LS2s. They may have the same operating system ute to sedan - but the gauge can indicate wrong after a tune. It can either stay up high too long or say that its empty very quickly when it still have plenty.

I am wondering about the cause and also the way to fix it.
Both issues have occurred after a base tune was used rather than a remodelled tune that was read from the actual car.

---

Didn't I warn you about that Steve?, it's been a common problem, even on VZ LS1's, you need to use the base file from the vehicle.

Cheers,
Ross

Aha, hence the 2bar custom OS's need to be based on the actual OS .tun from the vehicle.

I was wondering why that was.

The base files are not labelled differently. I did check and there are only 2 different operating systems for Aussie LS2s.... but there must be hidden settings that create more varieties than just the 2.

Sounds like it might even be calibrated per vehicle during manufacuturing dude. Based on Delco's comment. "is individual to each car"

Quote:

---

Originally Posted by oztracktuning

The base files are not labelled differently. I did check and there are only 2 different operating systems for Aussie LS2s.... but there must be hidden settings that create more varieties than just the 2.

---

Calibrations arent labeled differently , look at the checksums , if they are different the cals are different.

On the earlier PCM's DSKW was one of the most popular operating sysetms but there are hundreds of versions of it , holden change it monthly with revisions to the calibrations.

The are different fuel guage calibrations for V6, V8, sedan, wagon, utility and AWD. The problem here is that the instument cluster fuel guage calibration requires the correct ECM calibration to work. Prior to VZ the sender was wired direct to the instrument cluster and only required the correct instrument cluster calibration. VZ and later the sender was wired to the ECM and the information was sent via serial or can bus to the instrument cluster. Both calibrations in the cluster and ECM have to be in sync.

OK thanks to Delco - now having investigated all the codes and checksums. Make sure the fuel system checksum is the same. Then you know you have the same settings.