Tuned TCU detectable in stock ECU

[Schroedes]

Gentleman, was thinking of purchasing a used lozic tcu, it's a mild tune.. and keeping my stock TCU for any service work.. my question is, does the stock ECU store parameters etc that the dealership could see if there were any service needs , warranty work etc I needed? Of course I would swap the stock TCU back in first.. thanks

 

[Yves998]

TCU is 100% non detectable. ECU doesn’t storage anything. The only potential permanent code that’s not clearable code is from EWG, and that’s what stops most of us using JB4 EWG wires.

 

[Schroedes]

TCU is 100% non detectable. ECU doesn’t storage anything. The only potential permanent code that’s not clearable code is from EWG, and that’s what stops most of us using JB4 EWG wires.

Interesting, I wasn't aware of that about the EWG wires.. so it's just storing wastegwte valies

 

[rpoffen]

Interesting, I wasn't aware of that about the EWG wires.. so it's just storing wastegwte valies

The wires allow the jb4 to adjust the duty cycle of the signal going to the wastegate, one thing it can help do is help prevent the overboost that can happen with certain exhaust mods.

 

[Thomby]

So is the ECU logging the overboost condition itself, or the JB4's tweaked setting? I would've thought the EWG wires worked similarly to the other sensor connectors, in that the JB4 intercepts the true signal and passes on one within normal parameters for the ECU to see.

 

[rpoffen]

So is the ECU logging the overboost condition itself, or the JB4's tweaked setting? I would've thought the EWG wires worked similarly to the other sensor connectors, in that the JB4 intercepts the true signal and passes on one within normal parameters for the ECU to see.

The ECU triggers the overboost code, when it senses an inconsistency in some of the sensor inputs. Things like removing the primary and/or secondary CAT's can make the turbo spin up faster and present boost more than the ECU expects. The EWG wires, along with a setting in the jb4, reduces the wastegate response to try and compensate.

 

[Thomby]

The ECU triggers the overboost code, when it senses an inconsistency in some of the sensor inputs. Things like removing the primary and/or secondary CAT's can make the turbo spin up faster and present boost more than the ECU expects. The EWG wires, along with a setting in the jb4, reduces the wastegate response to try and compensate.

Right, I understand the cause/symptoms, but I'm not clear on what @Yves998 is saying is unclearable. Is it the overboost code itself that won't clear (meaning they could see that it happened at one point, but not whether you used a JB4 to fix it), or will the ECU see and log the fact that the JB4 is actively controlling the wastegate to prevent overboost?

If it's just the former, I wouldn't expect that to be a red flag, given that some users report encountering it just from particularly cold weather.

 

[Yves998]

Right, I understand the cause/symptoms, but I'm not clear on what @Yves998 is saying is unclearable. Is it the overboost code itself that won't clear (meaning they could see that it happened at one point, but not whether you used a JB4 to fix it), or will the ECU see and log the fact that the JB4 is actively controlling the wastegate to prevent overboost?

If it's just the former, I wouldn't expect that to be a red flag, given that some users report encountering it just from particularly cold weather.

Not really overboost. More like a EWG failure code or what. Once it’s been triggered that ECU itself would be problematic to tune while your car will work perfectly fine with spare ECU.