: Documents like ECU Pinout and Wiring Diagram Guide or SEAT 2002 Ibiza Wiring provide exact pin-by-pin breakdowns.
On most SIMOS 33A ECUs:
Connect to Pin 2 . For high-speed data stability, it is also recommended to tie Pin 28 directly to your ground source. 🌐 Data Communication Pins
The SIMOS 33A's top-side pinout is not a secret to be discovered in one simple diagram but a puzzle to be solved through careful research, community collaboration, and methodical testing. By understanding the ECU's family, leveraging the partial pin function knowledge available in forums, and following a rigorous verification process, you can confidently map your specific ECU. simos 33a pinout top
Would you like a simplified schematic showing power, ground, sensors, and actuators grouped separately for troubleshooting?
If you are replacing a faulty unit, remember that these ECUs often require or "immo-off" procedures. Tools such as Poldiag are frequently used by automotive locksmiths for these security resets.
For basic ECU power-up on a workbench, these primary connections are essential: Main ground (Terminal 31). Pin 3: Constant battery power (+12V, Terminal 30). Pin 62: Switched ignition power (+12V, Terminal 15). Diagnostic and Communication Pins : Documents like ECU Pinout and Wiring Diagram
| Pin | Function | Signal Type | Notes | |-----|----------|-------------|-------| | 1 | Ignition coil output (cyl 1) | Output | Low side driver | | 2 | Injector output (cyl 1) | Output | Saturation driver | | 3 | Injector output (cyl 2) | Output | | | 4 | Injector output (cyl 3) | Output | | | 5 | Injector output (cyl 4) | Output | | | 6 | Fuel pump relay control | Output | Grounds relay coil | | 7 | Lambda probe heater (front) | Output | Ground side | | 8 | Throttle valve position sensor (TPS) ground | Sensor Ground | | | 9 | TPS signal (wiper) | Input | 0.5-4.5V | | 10 | TPS 5V supply | Output | +5V reference | | 11 | Intake air temp (IAT) signal | Input | | | 12 | Coolant temp (ECT) signal | Input | | | 13 | MAP sensor signal | Input | Manifold absolute pressure | | 14 | MAP sensor 5V supply | Output | | | 15 | MAP sensor ground | Sensor Ground | | | 16 | Ignition coil output (cyl 2) | Output | | | 17 | Ignition coil output (cyl 3) | Output | | | 18 | Ignition coil output (cyl 4) | Output | | | 19 | +12V main relay output | Power | To sensors/actuators | | 20 | +12V permanent (battery) | Power | Direct from battery | | 21 | +12V from main relay | Power | ECU main supply | | 22 | Ground (power) | Ground | High current | | 23 | Ground (power) | Ground | High current | | 24 | Ground (sensor) | Sensor Ground | | | 25 | CAN High (if equipped) | Comm | Drivetrain CAN | | 26 | CAN Low (if equipped) | Comm | | | 27 | Knock sensor 1 signal | Input | | | 28 | Knock sensor 2 signal | Input | | | 29 | Crank position sensor (CKP) signal | Input | 60-2 wheel | | 30 | CKP sensor ground | Shield/Ground | | | 31 | Cam position sensor (CMP) signal | Input | Hall effect | | 32 | CMP sensor supply | Output | +5V or +12V | | 33 | CMP ground | Ground | | | 34 | Lambda probe signal (front) | Input | 0-1V narrowband | | 35 | Lambda probe ground (front) | Ground | | | 36 | Vehicle speed sensor (VSS) | Input | | | 37 | Brake light switch signal | Input | | | 38 | Clutch switch signal | Input | | | 39 | A/C request signal | Input | | | 40 | A/C compressor enable | Output | | | 41 | EPC warning lamp | Output | | | 42 | Check engine lamp (MIL) | Output | | | 43 | Diagnostic K-line (ISO 9141) | Comm | | | 44 | Idle air control (IAC) - close | Output | Stepper motor coil | | 45 | Idle air control (IAC) - open | Output | Stepper motor coil | | 46 | EVAP purge valve control | Output | | | 47 | Secondary air injection (SAI) relay | Output | | | 48 | Oxygen sensor heater (rear) | Output | If present | | 49 | Idle air control (IAC) - coil B | Output | | | 50 | Idle air control (IAC) - coil A | Output | | | 51 | Not used | - | | | 52 | Not used | - | | | 53 | +12V switched (e.g., from alternator) | Input | Load signal | | 54 | Power ground | Ground | | | 55 | Power ground | Ground | | | 56 | Sensor ground | Ground | | | 57 | Ignition switch input (Terminal 15) | Input | +12V when key ON | | 58 | Start signal (Terminal 50) | Input | +12V during cranking | | 59 | Engine speed output (to tachometer) | Output | Low side driver | | 60 | +12V backup (for adaptive memory) | Power | Permanent |
If you are currently troubleshooting a specific vehicle, let me know the (such as AZL, ALZ, or BMD) or the part number stamped on your Simos casing so I can provide the exact numerical pin assignments for your project. Share public link
The physical ECU unit typically carries part numbers like 06A906033 or 06A906033xx and the internal hardware is often identified by a starting with 5WP4xxxx , such as 5WP40019 05 or 5WP40019 07 . This makes it a close relative of the SIMOS 3PC and other SIMOS 3.3 variants that share much of the same core architecture and pinout philosophy. 🌐 Data Communication Pins The SIMOS 33A's top-side
The tone should be informative, practical, and cautionary. I will cite the specific search results that confirm the ECU's existence and applications, as well as those that hint at pinout sources. The response will be written in English, as per the user's question.
This write-up provides the (60-pin or 64-pin depending on production year), used in majority of SIMOS 33A ECUs. Always verify with your specific wiring diagram.
CAN bus communication occasionally requires a 120-ohm resistor bridged between CAN-H and CAN-L if your tuning tool doesn't feature a built-in terminator.
Current Flow Diagram for Simos Control | PDF | Fuel Injection - Scribd