Simos 33a Pinout Top 〈Premium Quality〉

The Siemens Simos 3.3A (06A 906 033 A) is a legacy engine control unit (ECU) found primarily in the Audi A3 8L and Volkswagen Golf Mk4 with the 1.6L 8V (102HP) petrol engine. Its pinout configuration is essential for technicians performing bench-top diagnostics, IMMO-off procedures, or EEPROM/Flash reading. Technical Overview

The Simos 3.3A belongs to the Simos 3 family, which is known for its relatively straightforward hardware but sensitivity to specific communication protocols when accessed via bench tools. Primary Application: Audi A3 I (8L), VW Golf IV 1.6i.

Key Components: Typically utilizes a 29F400 Flash chip and a 93C76 or similar EEPROM for data storage.

Engine Management: Capable of processing up to two knock sensor signals via piezo-resistive senders. Bench Pinout Configuration (Standard)

For bench-top reading and writing (using tools like PCMflash or MPPS), the following "Top" view pin connections are standard for the 80-pin or 121-pin connectors (check your specific hardware revision): Pin Number (Common 121-pin) +12V (Main Power) Permanent power supply to the ECU. +12V (Switched/Ignition) Ignition signal (Terminal 15). Ground (GND) Main chassis ground connection. K-Line (Data) Diagnostic communication channel. CAN High/Low Pins 19/20 (if equipped) High-speed bus communication. Performance and Reliability Review Pros:

Simplicity: Highly documented in tuning communities like ECU Connections, making it easy to troubleshoot or modify.

Durability: The hardware is robust and rarely suffers from internal component failure compared to newer, more complex units. Cons:

Reading Limitations: Some older variants may require "Boot Mode" (grounding a specific pin on the PCB) to write to the Flash memory.

Tool Compatibility: Modern tools like the KT200II can occasionally experience freezing or "not responding" errors when communicating with older Simos units in bench mode. Expert Tip

When working with the Simos 3.3A on the bench, ensure you use a stable 13.5V to 14V power supply. Voltage drops during the "Write" phase can corrupt the Flash memory, often requiring a desoldering of the chip to recover the unit using an external programmer. Simos 8.3/8.4 boot read ECU connection issue - Facebook

The Simos 3.3A is an engine control unit (ECU) commonly used in Volkswagen Group vehicles, such as the Audi A3 1.6L, to manage fuel injection and ignition systems. Understanding the "top" pinout is essential for bench-reading, remapping, or diagnosing electrical faults. Simos 3.3A Pinout Overview

For bench connections, the Simos 3.3A generally requires connections to power, ground, and a communication line (K-Line). Note that pin numbers may vary slightly by specific engine code (e.g., AEH or AKL), but standard bench-reading pins typically include: +12V Power (Permanent): Pin 3 +12V Switched (Ignition): Pin 1 Ground (GND): Pin 2 K-Line (Communication): Pin 43

For more detailed technical specifications and wiring diagrams, you can consult the SIMOS Injection Guide or the SIMOS 3.4 ALZ System Overview for related architecture. Key Components & Functions

The Simos 3.3A manages several critical engine functions. A complete "top" pinout map typically features connections for:

Injectors: Controlling the pulse width for fuel delivery to each cylinder.

Ignition Transformer: Managing the spark timing via a dedicated final stage.

Sensors: Monitoring the Hall Sender (G40), Engine Speed Sender (G28), and Knock Sensors (G61/G66).

Throttle Control: Operating the throttle valve actuator (V60) and potentiometers (G69/G88). Bench Reading and Diagnostics

Professionals often use specialized tools like the New Trasdata or Simos Tools to unlock and flash these units. For bench testing, ensure a stabilized power supply is used to avoid corrupting the EEPROM data.

If you are replacing a faulty unit, remember that these ECUs often require immobilizer adaptation or "immo-off" procedures. Tools such as Poldiag are frequently used by automotive locksmiths for these security resets.

The Siemens Simos 3.3A is a common engine control unit (ECU) found in VAG group vehicles (Volkswagen, Audi, Skoda, Seat), particularly for the 1.6L petrol engines (engine code BFQ).

A "top" pinout typically refers to the connection layout required for bench flashing or boot mode work using tools like OBDSTAR DC706 or MPPS. Simos 3.3A Bench Pinout Guide

When looking at the ECU connector pins from the front (connector side), use these primary connection points for basic communication: Permanent Power (+12V): Pin 3 and Pin 62. Ignition Power (+12V): Pin 1. Ground (GND): Pin 2. K-Line (Communication): Pin 43. CAN High (if applicable): Pin 119. CAN Low (if applicable): Pin 120. Key Technical Resources Siemens Simos 3.3 VAG (Audi, Seat, Skoda, Volkswagen)

The Connector Layout

When looking at the ECU with the connectors facing you and the mounting tabs at the top, the plugs are usually arranged from left to right. Below is a breakdown of the critical pins found in the standard layout.

Note: Pin locations can vary slightly between hardware revisions. Always look for the pin numbers stamped on the ECU plastic housing next to the connector slots.

Battery Pins (30)

A1, A2, A3 – Must all receive +12V from the main battery or a bench power supply (13.8V recommended). If any of these are missing, the ECU will not power internal drivers.
Current draw on bench: ~0.5–1.2A (idle) up to 8–10A (if driving injectors/coils).

Part 5: Top vs. Bottom Pinout – Critical Differences

Many online guides confuse the top (component side) and bottom (solder side) pinouts.

Golden Rule: When working with the top view, always ensure no metal tools touch two adjacent pins. The Simos 33A operates at 5V logic levels; a short between 5V_REF (Pin 31) and Sensor GND (Pin 30) will instantly destroy the 5V regulator. simos 33a pinout top

Important Notes for the "Top" View

Top View = Looking at the component side of the PCB (where the microcontroller, capacitors, and transistors are visible).
The connector is keyed (a small notch or missing pin area).
Pins are numbered from 1 to 60 in sequence, usually starting at the left side of the keying feature when viewed from the top.
This is a generic pinout; exact pin functions vary slightly by:
- Engine type (4, 5, or 6 cylinders)
- Vehicle manufacturer (VW, Audi, Seat, Skoda, Fiat, Opel)
- Model year (1990s–early 2000s)

Safety & Warning

This pinout is provided for reference and diagnostic purposes only. Do not probe or apply voltage to unknown pins without a factory wiring diagram for your specific vehicle. Incorrect wiring can destroy the ECU.

If you need the bottom (solder side) pinout or a harness-side (female connector) pinout, let me know.

The Simos 3.3A (often found in VAG 1.6L vehicles like the VW Golf, Jetta, or Audi A3) typically uses an 80-pin connector. For bench operations like reading pincodes or immobilizer service, specific "top" pins are used to power the unit and establish communication. Bench Connection Pinout

For direct wiring or "bench mode" using tools like the OBDSTAR DC706, the following standard pin assignments are used: +12V (Power): Pin 1 and Pin 3 Ground (GND): Pin 2 Ignition: Pin 62 K-Line (Communication): Pin 43 Internal Components

If you are opening the ECU for boot mode or repair, the SIMOS 3.3 board contains key ICs that control engine functions: Processor: Often a Siemens or Infineon C167 series. EEPROM: Typically a for immobilizer data storage. Flash: Usually a or 29F200 chip for the main engine map. Wiring Context

In vehicle wiring diagrams, the Simos control unit (J361) is centrally located in the plenum chamber and connects via the 80-pin T80 connector. Standard engine sensor pins include: Engine Speed Sensor (G28): Pin 82 Oxygen Sensor (G39): Pins 70, 71 Throttle Position Sensor (G79): Pin 73

Simos Control Unit Wiring Diagram | PDF | Fuel Injection - Scribd

Assuming you mean the Siemens SIMOS 33A engine control unit (ECU) connector pinout — common in some Volkswagen/Audi/Seat/Skoda vehicles — here’s a compact reference for the connector "Top" (often the 55-pin / 67-pin SIMOS variants vary; this follows the common 55-pin SIMOS 33A layout). Use this only as a guide — verify against vehicle-specific documentation before wiring.

Connector: SIMOS 33A — Top row (pin numbering left-to-right when viewing the ECU mating face with locking tab up). Pins are shown as: Pin number — Signal / Typical function — Notes

1 — GND (chassis ground) — ECU ground
2 — CAN High (CAN H) — Powertrain CAN bus high
3 — CAN Low (CAN L) — Powertrain CAN bus low
4 — Battery + (B+) — Permanent battery supply (fused)
5 — Ignition 15 (IGN) — Switched ignition supply
6 — 5V reference — Sensor supply reference
7 — MAP / Boost sensor input — Manifold absolute pressure
8 — IAT / Air temp sensor input — Intake air temperature
9 — CLT / Coolant temp sensor input — Engine coolant temperature
10 — Crankshaft position (CKP) — Primary crank sensor input
11 — Camshaft position (CMP) — Cam sensor input
12 — Knock sensor 1 — Knock input (engine bank-dependent)
13 — Knock sensor 2 — Secondary knock input (if fitted)
14 — Fuel injector 1 driver — Low-side injector driver (cylinder 1)
15 — Fuel injector 2 driver — Low-side injector driver (cylinder 2)
16 — Fuel injector 3 driver — Low-side injector driver (cylinder 3)
17 — Fuel injector 4 driver — Low-side injector driver (cylinder 4)
18 — Fuel pump control (FP relay driver) — Fuel pump relay control (switched output)
19 — Ignition coil driver 1 — Coil driver (or coil pack control)
20 — Ignition coil driver 2 — Coil driver
21 — Ignition coil driver 3 — Coil driver
22 — Ignition coil driver 4 — Coil driver
23 — TPS / Throttle position sensor — Throttle potentiometer input
24 — EGR valve control / N75 — EGR or turbo bypass control (model dependent)
25 — Idle control valve (IAC) — Idle air control / stepper or PWM
26 — Lambda sensor (oxygen) heater control — O2 sensor heater output
27 — Lambda sensor signal (upstream) — O2 sensor voltage input (bank 1)
28 — Secondary lambda / downstream signal — (if fitted)
29 — CAN GND / Chassis reference for CAN — optional/variant
30 — Vehicle speed / VSS — Speedometer/ABS speed signal input
31 — Brake switch input — Brake pedal / cruise inhibit
32 — Clutch switch input — Clutch pedal / cruise inhibit
33 — Neutral / Park switch — Gear selection input (if applicable)
34 — A/C request input — Air conditioning compressor request
35 — Fan control output 1 — Radiator fan relay control
36 — Fan control output 2 — Radiator fan stage 2
37 — Evaporative purge valve control — EVAP canister purge
38 — Ambient air temp input — Ambient temp sensor (if used)
39 — Accelerator pedal position sensor 1 — APS sensor 1
40 — Accelerator pedal position sensor 2 — APS sensor 2 (redundant)
41 — Start inhibit / starter motor input — Cranking detection input
42 — Immobilizer / PATS input — Immobilizer transponder data line
43 — Serial data / K-line (diagnostic) — Older K-line diagnostic port
44 — LIN bus / secondary serial — Variant-dependent
45 — CAN 2 High / FlexRay (variant) — Secondary bus high (if present)
46 — CAN 2 Low / FlexRay (variant) — Secondary bus low (if present)
47 — Alternator sense / L-terminal — Charge warning / alternator field sense
48 — Fuel rail pressure sensor — Fuel pressure sensor input (if fitted)
49 — Turbocharger control (VNT / boost) — Boost control solenoid driver
50 — Secondary injector drivers / spare outputs — Variant-dependent
51 — Knock ground / sensor ground — Dedicated sensor ground
52 — Switched supply for sensors (IGN2) — Secondary switched supply
53 — Ground (battery negative) — Main ground return
54 — Reserved / manufacturer test pin — DO NOT CONNECT
55 — Reserved / manufacturer test pin — DO NOT CONNECT

Notes:

Pin assignments vary by vehicle, SIMOS hardware revision, and connector variant (55-pin, 67-pin, etc.). Some pins above are variant-dependent or optional.
Always confirm with the vehicle’s factory wiring diagram or the ECU label/part number before applying power or connecting signals.
If you need the exact pinout for a specific vehicle (make, model, year, engine code), provide those details and I will produce a vehicle-specific pinout.

Related search suggestions provided.

The Siemens Simos 3.3A is an Engine Control Unit (ECU) commonly found in VAG group vehicles (Volkswagen, Audi, Seat, Skoda) from the early-to-mid 2000s, such as the Audi A3 1.6L (AVU engine). Simos 3.3A Pinout for Bench Operations

To perform operations like reading the pincode or "Immo Off" on a bench, you must connect to specific pins on the ECU's main connector. The following pinout is commonly used by professional tools like the OBDSTAR DC706: +12V (Power): Pins 3, 23, and 62 GND (Ground): Pins 1 and 2 K-Line (Communication): Pin 17 Technical Capabilities

Engine Management: The Simos 3.3 system manages fuel injection, ignition, and electronic throttle actuation (EPC) in a single unit.

Memory Components: It typically contains a 29F400BB Flash chip and a 93C76 EEPROM.

Bench Reading: Tools such as the OBDSTAR DC706 or PCMtuner can read and write both the Flash and EEPROM data in bench mode to clone the ECU or bypass immobilizers. User Experience and Tips

OBD Limitations: While some Simos versions support OBD reading, users often report that Simos 3.3 may not work via OBD for full read/write operations, necessitating a full system pinout on the bench.

Resources: For detailed visual diagrams, automotive professionals frequently use databases like ImmoOFF or Cairo Car Tuning which provide high-resolution PDF pinout maps.

Are you planning to perform a clone or an immobilizer delete on this specific ECU?

Siemens Simos 3.3A (often labeled Simos 33A) is an engine control unit (ECU) primarily used in Volkswagen and Audi vehicles, such as the Audi A3 1.6L (engine codes AEH, AKL). ECU Overview and Key Features Application : Management system for 4-cylinder petrol engines. Connector Type : 80-pin multi-plug connector. Service Tasks : Common procedures include reading pin codes for (immobilizer bypass) or cloning using bench tools like the Simos 3.3A Pinout Summary

Based on the standard 80-pin wiring diagram for the Simos 3.3A (1.6L engine), the following are the primary power, ground, and communication pins: Pin Number(s) Ground (Main) Positive (+) Battery (Terminal 30) Ignition Switch (Terminal 15) K-Line (Diagnostics) Fuel Pump Relay Control Engine Speed Sensor (G28) Injector and Sensor Wiring Simos series Current Flow Diagram

details the following specific connections for the fuel system: : Controlled via pins that trigger based on firing order. Hall Sender (G40) : Typically connected to pin 62. Coolant Temperature Sender (G62) : Provides input for engine management adjustments. Bench Connection Guide

For "top" or bench-mode access (for flashing/reading), professional tools often use the following standard setup: Power (+12V) : Pin 18 (Permanent) and Pin 3/37 (Switched). Ground (-) : Pins 1 and 2. Communication

: K-Line at Pin 43 is the primary method for Simos 3.3A/3.4A ECUs.

Simos Control Unit Wiring Diagram | PDF | Fuel Injection - Scribd

The pinout for the Siemens Simos 3.3a ECU , commonly found in VAG (Volkswagen, Audi, Seat, Skoda) vehicles with 1.6L engines (like the AVU or BFQ codes), is essential for bench reading, pincode retrieval, and IMMO-OFF procedures. Core Bench Pinout (Power & Communication) For standard "on-the-bench" operations using tools like OBDSTAR DC706 , the primary connections are made to the 81-pin main connector Pin Number(s) Description +12V (Permanent) Main power supply +12V (Ignition) Switched power Ground (GND) Main chassis ground Diagnostic communication line Component-Specific Pinout Data The Siemens Simos 3

Beyond basic power, specific pins handle critical engine actuators and sensors: Fuel Injector II: Pin 33A (Signal from vehicle's ECU). Fuel Injector I: Engine Speed Sender (G28):

Inductive sender usually connected to dedicated inputs for crank angle calculation. Camshaft Position (G40): Hall sender used for engine speed calculation if G28 fails. Programming Notes These units typically feature a 29F400BB Flash 93C76 EEPROM Bench Mode: Most modern tools can perform Read Pincode

via K-Line on the bench without opening the case, provided the 12V, GND, and K-Line connections are correct. Boot Mode:

If bench reading fails, some variants require grounding specific pads on the PCB (BSL mode) to enable programming. Always "probe" or verify continuity to the processor pins before applying voltage to unknown pads.

For detailed wiring diagrams including sensor colors and relay locations, the VW ElsaWin software

are the standard professional resources for these older VAG systems. or to resolve an immobilizer issue

Understanding the pinout for the Siemens Simos 3.3A ECU—commonly found in Volkswagen models like the Beetle, Golf, and Polo—is essential for bench programming, diagnostics, or IMMO off procedures. Simos 3.3A ECU Bench Pinout

For "bench" mode (connecting directly to the ECU pins without the car), you typically need to establish power, ground, and communication. According to standard technical guides for tools like MPPS V18 and PCMtuner, the pin assignments are: +12V (Power): Pins 1, 3, and 62 GND (Ground): Pin 2 K-Line (Communication): Pin 43

Note: Some variations may use Pin 43 specifically for the K-Line diagnostic signal required for reading the EEPROM or flash memory on the bench. Professional Bench Tools

Several tools are frequently used to interface with this ECU for cloning or reading pincodes:

DC706: Often used for IMMO off and pincode reading directly on the bench.

BitBox: Supports Simos modules for K-Line reading and writing.

PCMflash: Commonly uses Module 1 or specialized boot protocols for Simos units. Important Service Tips

Stable Power: When performing "Bench" or "Boot" operations, always use a stabilized 12V-14V power supply. Low voltage during a write process can "brick" the ECU.

IMMO Off: Many technicians seek this pinout specifically to perform an IMMO off, which is a common fix for older VW vehicles with failing immobilizer systems.

Visual Verification: Always refer to a physical diagram or the markings on the ECU connector to ensure you are counting the pins from the correct side (top-down vs. front-facing).

A very specific topic!

The Simos 33A pinout is a configuration used in some diesel engines, particularly in the automotive industry. I'll provide a detailed review of the Simos 33A pinout, focusing on the top aspects.

What is Simos 33A?

Simos 33A is a type of engine control unit (ECU) used in diesel engines. It's a part of the Simos (Siemens/Infineon/ Motorola/ Osram) family of ECUs, which are widely used in various diesel engine applications.

Pinout Overview

The Simos 33A pinout refers to the configuration of the ECU's connector pins, which connect to various engine sensors, actuators, and other components. The pinout is crucial for understanding how the ECU interacts with the engine and its components.

Top Aspects of Simos 33A Pinout

Here's a detailed review of the top aspects of the Simos 33A pinout:

Connector Pin Layout: The Simos 33A ECU typically has a 70-pin or 80-pin connector. The pinout is divided into several sections, including:
- Power supply and ground pins
- Sensor input pins (e.g., crankshaft position, camshaft position, engine speed, fuel pressure)
- Actuator output pins (e.g., fuel injectors, fuel pump, EGR valve)
- Communication pins (e.g., CAN bus, LIN bus)
Sensor Inputs: The Simos 33A ECU receives input from various sensors, including:
- Crankshaft position sensor (CKP)
- Camshaft position sensor (CMP)
- Engine speed sensor (ESS)
- Fuel pressure sensor (FPS)
- Boost pressure sensor (BPS)
- Coolant temperature sensor (CTS)
- Intake air temperature sensor (IATS)
Actuator Outputs: The Simos 33A ECU controls various actuators, including:
- Fuel injectors
- Fuel pump
- Exhaust gas recirculation (EGR) valve
- Turbocharger control valve (TCV)
- Variable geometry turbocharger (VGT) actuator
Communication Interfaces: The Simos 33A ECU communicates with other components via:
- CAN bus (Controller Area Network)
- LIN bus (Local Interconnect Network)
Power Supply and Ground: The Simos 33A ECU requires a stable power supply and ground connection to operate correctly.

Technical Specifications

Here are some technical specifications of the Simos 33A pinout:

Operating voltage: 4.5V to 5.5V
Operating temperature: -40°C to 125°C
ECU type: Diesel engine control unit
Pinout: 70-pin or 80-pin connector

Conclusion

The Simos 33A pinout is a complex configuration that requires a good understanding of diesel engine systems and ECU interactions. By reviewing the top aspects of the Simos 33A pinout, you'll have a better understanding of how the ECU interacts with engine sensors, actuators, and other components. If you're working with this ECU, it's essential to consult the official documentation and technical specifications to ensure accurate and safe operation.

Simos 3.3a is a variant of the Siemens Simos engine control unit (ECU) commonly found in Volkswagen Group vehicles, such as the VW Jetta and Golf. Pinout diagrams for these ECUs are essential for bench flashing, diagnostic testing, or repair. General Pin Identification for Simos 3.3/3.3a When viewing the ECU connector from the

(the side where the harness plugs in), pins are generally numbered in a specific sequence to prevent incorrect wiring. Pin 1 Location

: Typically identified by a small dot or a molded "1" near one of the corners of the connector housing. Reading Sequence

: Numbers usually proceed sequentially along a row before moving to the next. Key Identification Points Main Power (+12V) : Often found on specific pins like Terminal 30 for constant power and Terminal 15 for ignition-switched power. Ground (GND) : Common ground connections are often labeled as Terminal 31 Communication

: K-Line communication for diagnostics is frequently assigned to a single pin (e.g., Pin 37 or similar depending on the specific VAG harness version). EMIT Connect Bench Connection Essentials

For common VAG Simos ECUs, standard connections often follow this general pattern: Power (+12V)

: Pins 2, 16, or 121 (depending on the specific 80-pin or 121-pin configuration). : Pins 5, 9, or 121. : Pin 110 or Pin 48 in many Siemens Simos layouts. Recommended Resources for Diagrams

Because pinouts can vary slightly based on the specific engine code (e.g., AEH or AKL), it is critical to verify the schematic for your exact vehicle. Detailed technical guides can be found on: Ross-Tech Wiki for VAG-specific diagnostic and wiring information. Scribd ECU Manuals for specific current flow diagrams. Do you need the specific pin numbers for a bench power-up, or are you looking for sensor-specific wiring locations?

Current Flow Diagram for Simos Control | PDF | Fuel Injection - Scribd

The Simos 3.3A (often paired with Simos 3.4A) is an engine control unit (ECU) primarily found in VAG group vehicles like the and VW Golf with 1.6L engines.

For bench testing, reading, or flashing this ECU, the "top" pinout typically refers to the main 80-pin connector (T80). Simos 3.3A Key Pin Connections

Based on standard VAG Simos 3 series wiring, the essential pins for power and communication are generally as follows: Main Power (+12V): Pin 1: Main battery positive (Terminal 30). Pin 3: Ignition switched positive (Terminal 15). Ground (GND): Pin 2: Main chassis ground (Terminal 31). Communication:

Pin 43: K-Line (Diagnostic interface for tools like VAG 1551 or VAS 5051).

Pin 19 / 21: Often used for CAN-High and CAN-Low in later CAN-bus variants, though early 3.3A units rely heavily on the K-Line. Connector Layout The Simos 3.3A uses a large 80-pin connector.

T80 Connector: The pins are usually numbered from left to right, often in rows (e.g., 1-20, 21-40, etc.).

Internal Access: For some advanced boot-mode reading, soldering pads may be located in the middle of the board, though this is more common for Simos 6.x and higher series. Visual Reference Guides

You can find detailed wiring diagrams and full 80-pin maps on technical document platforms like: Simos 3 Motor Management Overview (via Scribd). Simos 1.6L Wiring Diagram (via Scribd).

Are you trying to perform a specific task with this ECU?I can provide more targeted details if you Troubleshooting a no-start or sensor signal issue? Performing an engine swap (e.g., 1.4L to 1.8T)? Current Flow Diagram for Simos Control | PDF - Scribd

For the Siemens Simos 3.3A (often labeled with part number 06A 906 033 A) found in VAG vehicles like the Audi A3 1.6i, the "top" or bench pinout is primarily used for reading pincodes, IMMO OFF procedures, or cloning. Simos 3.3A Bench Pinout

To power the ECU and establish communication on the bench, use the following pin assignments on the main connector: Pin 1: Ground (GND / Terminal 31) Pin 2: Ground (GND / Terminal 31) Pin 3: Permanent Positive (+12V / Terminal 30) Pin 43: K-Line (Communication line for diagnostic tools) Pin 62: Switched Positive (Ignition / Terminal 15) Internal Board Access

For certain operations like reading the 29F400 Flash or the 93C76/93C86 EEPROM, you may need to open the ECU. Tools like the DC706 ECU Tool provide specific wiring diagrams for direct board connection to bypass the immobilizer or clone data.

Are you planning to use a specific tool like PCMtuner or K-Tag for this connection?

Current Flow Diagram for Simos Control | PDF | Fuel Injection - Scribd

Power Supply & Ground (The Essentials)

Before trying to communicate with the ECU, you must power it up correctly on the bench.

Pin 1 (varies by block): Often Switched Ignition (Terminal 15).
Pin 2 (varies by block): Ground (Terminal 31).
Constant Battery Power (Terminal 30): Usually a heavy gauge wire found on the main connector block.

Pro Tip for Bench Testing: When powering the SIMOS 33A on a bench, you need to supply Terminal 30 (12V+) and Terminal 15 (Ignition 12V+), along with a solid **Ground