Bosch M797 Pinout Better Jun 2026

Why your scanner won't connect.

| Pin No. | Signal Name | Type | Description | | :------ | :------------------------- | :----- | :----------------------------------------- | | 1 | Lambda Probe Heater | Output | Heater circuit for oxygen sensor | | 2 | Ignition Coil Cyl. 2 | Output | Controls ignition for cylinder 2 | | 3 | Ignition Ground | Ground | Ground for ignition system | | 4 | (Not used) | - | | | 5 | Ignition Coil Cyl. 1 | Output | Controls ignition for cylinder 1 | | 6 | Injector Cyl. 2 | Output | Fuel injector signal for cylinder 2 | | 7 | Injector Cyl. 3 | Output | Fuel injector signal for cylinder 3 | | 8 | (Not used) | - | | | 9 | Immobilizer Signal | Output | Connects to the immobilizer antenna module | | 12 | Permanent Battery Positive | Input | Always-on +12V power | | 13 | Ignition Switch Positive | Input | Switched +12V power | | 14 | Main Relay Control | Output | Controls the main power relay | | 15 | Engine Speed Sensor A | Input | Crankshaft position signal A | | 16 | Throttle Position Sensor | Input | TPS voltage signal | | 18 | Oxygen Sensor (Lambda) | Input | Primary O2 sensor signal | | 19 | Knock Sensor A | Input | Signal from knock sensor | | 20 | Knock Sensor B | Input | Signal from knock sensor (if equipped) | | 27 | Injector Cyl. 1 | Output | Fuel injector signal for cylinder 1 | | 29 | MIL (Check Engine Light) | Output | Controls the "Check Engine" lamp | | 34 | Engine Speed Sensor B | Input | Crankshaft position signal B | | 35 | Sensor Ground 3 | Ground | Ground reference for sensors | | 37 | Manifold Absolute Pressure | Input | MAP sensor signal | | 39 | A/C Evaporator Thermistor | Input | Air conditioning system sensor | | 40 | Intake Air Temperature | Input | IAT sensor signal | | 42 | Coolant Temperature Sensor | Input | ECT sensor signal | | 46 | Purge Valve | Output | Evaporative emissions system control | | 47 | Injector Cyl. 4 | Output | Fuel injector signal for cylinder 4 | | 48 | (Not used) | - | | | 50 | Radiator Fan Relay | Output | Controls the cooling fan relay | | 51 | Electronic Ground 2 | Ground | Power ground for electronics | | 53 | Electronic Ground 1 | Ground | Power ground for electronics | | 59 | Vehicle Speed Sensor | Input | VSS pulse signal | | 61 | Power Ground 1 | Ground | High-current power ground | | 63 | Switched Power (Injectors) | Input | +12V power for injectors | | 64-67 | Idle Air Control Stepper | Output | Controls IACV stepper motor phases A-D | | 69 | Fuel Pump Relay | Output | Controls the fuel pump relay | | 70 | A/C Compressor Clutch | Output | Controls the A/C compressor relay | | 71 | K-Line | I/O | Diagnostic communication line | | 75 | A/C Request Switch | Input | Signal from A/C switch inside the car | | 79 | Camshaft Position Sensor | Input | CMP signal for cylinder identification | | 80 | Power Ground 2 | Ground | High-current power ground | bosch m797 pinout better

What specific (e.g., K-Tag, PCMTuner, PCMflash) are you using? Why your scanner won't connect

The M7.9.7 typically uses a single 121-pin or sometimes a 104-pin connector plug depending on the vehicle manufacturer variant (e.g., Kia vs. Lada). However, the internal logic and mapping are very similar. Essential Pinout Functions (Simplified for Troubleshooting) 2 | Output | Controls ignition for cylinder

I can tailor the physical connection schematics to perfectly match your gear.

Using a properly designated cable (like F32GN037C/D ) ensures all ground and power wires are connected correctly.

If you are building a custom harness for a stand-alone or piggyback, tap Pin 26. It is the universal backdoor to the M797.