Syvecs Forums

Hi
I have a S7 set up ECU on Porsche 996TT with legacy expander and Plex SDM 500 dash.
car was working fine we have around 10AEM sensors wire up the system. Clutch pedal
EX Maps (2) FPR, EOP, ECP, CCP, FLEX, MAP sensor. Car did not start now and the warnings I get.
on Smon are "Inputs U24 (Turbine inlet Pressure) Voltage limit voltage failure Share commons Failure
and U25 Voltage Limit Voltage Failure Slave Common Failure Fuel composition no signal salve comms failure.
Any idea where to look for these warnings? Any help will be appreciated.

mechtronic wrote: Sun Nov 19, 2023 8:58 pm Hi
I have a S7 set up ECU on Porsche 996TT with legacy expander and Plex SDM 500 dash.
car was working fine we have around 10AEM sensors wire up the system. Clutch pedal
EX Maps (2) FPR, EOP, ECP, CCP, FLEX, MAP sensor. Car did not start now and the warnings I get.
on Smon are "Inputs U24 (Turbine inlet Pressure) Voltage limit voltage failure Share commons Failure
and U25 Voltage Limit Voltage Failure Slave Common Failure Fuel composition no signal salve comms failure.
Any idea where to look for these warnings? Any help will be appreciated.

Is this a new install ? has it ever ran before ? other ?

Do you have these inputs in use, and assigned correctly in the I/O configuration ?

Post a screen shot of Scal during this.

stevieturbo wrote: Mon Nov 20, 2023 6:15 pm

mechtronic wrote: Sun Nov 19, 2023 8:58 pm Hi
I have a S7 set up ECU on Porsche 996TT with legacy expander and Plex SDM 500 dash.
car was working fine we have around 10AEM sensors wire up the system. Clutch pedal
EX Maps (2) FPR, EOP, ECP, CCP, FLEX, MAP sensor. Car did not start now and the warnings I get.
on Smon are "Inputs U24 (Turbine inlet Pressure) Voltage limit voltage failure Share commons Failure
and U25 Voltage Limit Voltage Failure Slave Common Failure Fuel composition no signal salve comms failure.
Any idea where to look for these warnings? Any help will be appreciated.connections game

Is this a new install ? has it ever ran before ? other ?

Do you have these inputs in use, and assigned correctly in the I/O configuration ?

Post a screen shot of Scal during this.

Those are also the questions I am wondering.

mechtronic wrote: Sun Nov 19, 2023 8:58 pm Hi
I have a S7 set up ECU on Porsche 996TT with legacy expander and Plex SDM 500 dash.
car was working fine we have around 10AEM sensors wire up the system. Clutch pedal
EX Maps (2) FPR, EOP, ECP, CCP, FLEX, MAP sensor. Car did not start now and the warnings I get.
on Smon are "Inputs U24 (Turbine inlet Pressure) Voltage limit voltage failure Share commons Failure
and U25 Voltage Limit Voltage Failure Slave Common Failure Fuel composition no signal salve Geometry Dash comms failure.
Any idea where to look for these warnings? Any help will be appreciated.

It could be that the CAN/RS485 wire is broken, there is no power supply to the Expander, or the configuration in SCal does not match.

First 15 minutes: Bitlife check/clean/tighten ground(s) and check fuses for the sensor 5V/12V and expander. Reseat big connectors.

Next 30 minutes: with multimeter, verify 5V ref and sensor ground continuity and measure U24/U25 voltages at their plugs with ignition ON.

If still failing: check expander power and CAN/serial wiring; replace/repair expander or wiring if it’s unpowered or CAN lines are shorted.

If you want, send me: the exact 5V/12V measurements at the sensor connector, continuity values to ground, and whether the expander shows any power. With those numbers I can help interpret them and advise the next repair step (e.g., replace harness, rebuild connector, replace expander).