Simos 33a Pinout Top May 2026

Below is the Simos 33A pinout top view for the main 154-pin connector. This table lists pins visible from the top side when the connector is unmated from the ECU and facing upward.

| Pin | Signal Name | Function | Typical Color (OEM) | |------|----------------|------------------------------------|------------------------| | A1 | BATT+ | Main battery voltage (30) | Red / Red-Blue | | A2 | BATT+ | Main battery voltage (30) | Red / Red-Blue | | A3 | BATT+ | Main battery voltage (30) | Red | | A4 | GND | Power ground | Brown / Black | | A5 | GND | Power ground | Brown | | A6 | GND | Power ground | Brown | | A7 | 15_IGN | Ignition switched power (15) | Green-Black | | A8 | 87_WU | Relay output (main relay) | Red-Yellow | | B1 | INJ_1 | Injector cylinder 1 | Yellow | | B2 | INJ_2 | Injector cylinder 2 | White | | B3 | INJ_3 | Injector cylinder 3 | Blue | | B4 | INJ_4 | Injector cylinder 4 (if 4-cyl) | Violet | | B5 | IG_A | Ignition coil A (cyl 1 & 4) | Green | | B6 | IG_B | Ignition coil B (cyl 2 & 3) | Green-Yellow | | C1 | O2_11 | Lambda sensor 1, bank 1 (pre-cat) | Black / Gray | | C2 | O2_12 | Lambda heater ground | White / Brown | | C3 | O2_21 | Lambda sensor 2, bank 1 (post-cat) | Gray | | C4 | TPS_5V | Throttle position sensor 5V ref | Orange | | C5 | TPS1_SIG | TPS signal (main) | Orange-Black | | C6 | TPS2_SIG | TPS signal (redundant) | Orange-Red | | D1 | CAN_H | CAN bus (high) | Orange / Yellow | | D2 | CAN_L | CAN bus (low) | Orange / Brown | | D3 | K_LINE | K-line diagnostic (ISO 9141) | Purple | | D4 | CKP_SIG | Crankshaft position sensor signal | Shielded pair (Blue/White) | | D5 | CMP_SIG | Camshaft position sensor signal | Shielded pair (Green/White) | | D6 | ECT_SIG | Engine coolant temperature sensor signal | Brown-Red | simos 33a pinout top

📌 Note: This table shows the most common assignments for a 4-cylinder Simos 33A. V6 or diesel variants may have different pinouts. Always check your specific OEM documentation. Below is the Simos 33A pinout top view

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: This table shows the most common

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.

Sometimes you don't have a pinout table. Using the top view of the PCB, you can identify critical connections with basic tools.