Bosch Ecu Pinout Datasheet Jun 2026

"All sensor ground returns are isolated from chassis ground. Do not continuity test between T121/13 and chassis ground – use ECU ground T60/4 only."

. On the screen, the software began to probe the ECU's silence. For three minutes, nothing happened. Then, a progress bar flickered to life. Bosch Ecu Pinout Datasheet

We see it all the time: A mechanic assumes pin 40 on a Volvo Bosch ECU is the same as pin 40 on a BMW Bosch ECU. "All sensor ground returns are isolated from chassis ground

While not explicitly shown as a "pin," the datasheet implies protection circuits. Inputs are often clamped to the supply rails via Zener diodes. If a 12V signal is accidentally applied to a 5V sensor input pin (because the user misread the datasheet), the internal protection fails, often destroying the ECU's analog-to-digital converter (ADC) channel. For three minutes, nothing happened

The Bosch datasheet includes a tiny block diagram. It shows that the for the crank sensor comes from an internal voltage regulator, but only after the ECU sees valid power on T60/2 (Terminal 15) for more than 50ms.