E38 full flash using TC

**Montecarlodrag** · 03-18-2016

I'm trying to do a full flash to a E38 ECM using a .cal I downloaded here. Winflash is not letting me do the flash, it says it's incompatible. I checked "Full Program" but didn't help. The cal opens fine in the tuner program.
I can flash the same .cal I read from the ECM, just can't flash other files I read from other ECMs or download from internet. I'm aware of the risks involved with flashing E38 ECMs with a different OS, but I have no choice. I'm trying only 2007-2008 .cals since this ECM is a 2007.

This is the first time I try to do this, I always edit the same file I read from the ECM and flash it back, never had an issue until today, the .cal I read from the ECM isn't accepting OS patches (to disable VATS) so I can't start the engine. That's why I'm trying to flash a different cal, to be able to apply the VATS patch.

Thanks

**LRT** · 03-18-2016

I think in TC when you select the Force Full Program option with an E38, segments 7 and 8 must be the same in both of the calibrations, to allow the flash to proceed.

Post the cal that you read out of the E38 ... will see if I have something compatible for you to try.

**kur4o** · 03-18-2016

Maybe full flash is unstable and risky via TC.
Why don`t you update it with stock os cal id with GM Oem tool first.
Then read with TC and modify. You will need a valid vin with the OS you want.
I doubt there is internal hardware changes at the PCM side.

**Montecarlodrag** · 03-19-2016

I don't have the tools to flash using OEM software.
Later today I'll post the .cal file I have

Thanks guys

**LRT** · 03-19-2016

Originally Posted by kur4o

Maybe full flash is unstable and risky via TC.
Why don`t you update it with stock os cal id with GM Oem tool first.
Then read with TC and modify. You will need a valid vin with the OS you want.
I doubt there is internal hardware changes at the PCM side.

TC works great with E38s - no issues. This is simply part of its quality assurance checks before flashing a different operating system - to prevent issues caused by incompatible calibrations. With the E38, tuning software can only write 6 out of the 8 segments. One of the non-accessible segments is the throttle controller - that is why there is a compatibility check.

**1project2many** · 03-19-2016

One of the non-accessible segments is the throttle controller - that is why there is a compatibility check.

Is this segment non-accessible due to software author choice? I'm imagining concerns over incorrect throttle settings causing dangerous operation... Or is the E38 constructed in a way that segment 7 just can't be reflashed through the OBDII port?

**LRT** · 03-19-2016

E37, E38, E67, E78, E83, E92 (and more) ECMs, are dual core processors. One of the cores is readable and writable - this contains the operating system and most of the calibration. The other core is write only - it cannot be read. It contains the throttle controller. As this core cannot be read - it is not accessible by any tuning software.

To fully program one of these ECMs requires the use of GM software (SPS / TIS), and is programmed via the OBDII (DLC) port.