Simos 33a Pinout Top ~upd~ -
The "Simos 33A" is often paired with the Simos 18.x software family. Many online pinouts for "Simos 18" apply directly to the 33A hardware. Do not confuse this with the older Simos 3.8 or Simos 8.5.
: Sensitive signal lines for components like the mass airflow sensor (MAF), oxygen sensors, and digital K-Line diagnostic signals. Simos 33A Master Pinout Configuration
| Pin | Signal Name | Function | Typical Color (OEM) | |------|----------------|------------------------------------|------------------------| | | 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 |
Connect the black ground clip to the designated negative terminal. simos 33a pinout top
When interfacing directly on the bench via breakout boxes or boot-mode programming tools, specific pins must be populated to power up the ECU and establish stable data packet transfers. Signal Type Description Designated Physical Pin Main Chassis / Battery Negative Pin 1 & Pin 2 Permanent Power Terminal 30 (+12V Battery Const.) Pin 3 Switched Ignition Terminal 15 (+12V Key-On Switching) Pin 62 Diagnostic Comms ISO-9141 K-Line Serial Data Pin 43 Fuel Injector 1 Ground-Side Switched Output Driver Pin 31 Fuel Injector 2 Ground-Side Switched Output Driver Pin 33 Step-by-Step Bench Connection Protocol
Gently pry up the aluminum top casing cover to expose the main printed circuit board (PCB). EEPROM (93C76) & Flash (AM29F400BB) Procedures
The hardware split-connector splits internal tasks into two distinct areas: The "Simos 33A" is often paired with the Simos 18
To wake up the Simos 3.3A on a table using standard chip tuning tools like PCMFlash , KESS, or universal diagnostic hardware, you must wire the main 121-pin multi-connector carefully.
What and engine code are you servicing?
: Hook up the permanent +12V feed to Pin 3 , then attach the switched ignition lead to Pin 62 . : Sensitive signal lines for components like the
If an OBD or standard bench-pin protocol fails to initiate reading, the ECU must be opened. Grounding the boot pin on the motherboard while powering up forces the processor into an open state, allowing low-level writing tools like the KT200 to overwrite corrupted sectors.
If you are dealing with a specific issue like a , misfire , or trying to tune the ECU, I can provide more specific instructions if you tell me: Which tool are you using? (KTAG, KESS, etc.)
If you need a high-resolution top-down pinout for a specific wiring job, these resources are the most reliable:
: Often required to "wake up" the unit for reading/writing. Specific Wiring Details (Reference)
[Simos 3.3A Multi-Connector Layout] +-------------------------------------------------------+ | [Pin 1: GND] | | [Pin 2: GND] | | [Pin 3: +12V VCC] | | [Pin 41: CAN-H] [Pin 42: CAN-L] | | [Pin 43: K-Line] | | | | [Pin 62: Ignition] +-------------------------------------------------------+ Grounding the Boot Pin
