The Toyota 3S-FE, a staple of the Celica, Camry, and RAV4 lineages, utilizes a Bosch-style L-Jetronic or TCCS (Toyota Computer Control System) depending on the production year. Early models often feature a 10P-18P-14P configuration, while later OBD-I and early OBD-II variants shifted toward the 26P-16P-22P block connectors. Standard ECU Pinout Configuration (Common 26P/16P/22P Type) Connector A (26-Pin): Power and Grounds Description Battery +12V Constant power for ECU memory +B Switched +12V Main power from EFI relay W Check Engine Light Ground trigger for dash warning E1 Engine Ground Main ECU ground to intake manifold E01 Power Ground High-current ground for injectors Connector B (16-Pin): Sensors and Inputs Description VC 5V Reference Power supply for MAP/TPS sensors PIM MAP Sensor Intake manifold pressure signal THW Coolant Temp Resistance-based temperature signal THA Intake Air Temp Air density calculation signal VTA TPS Signal Throttle position voltage Connector C (22-Pin): Actuators and Ignition Description #10 Injector 1 & 3 Pulse ground for fuel delivery #20 Injector 2 & 4 Pulse ground for fuel delivery IGT Ignition Trigger Timing signal sent to the igniter IGF Ignition Confirm Feedback signal from igniter to ECU ISC1 Idle Speed Stepper motor control for idle Critical Troubleshooting Pathways
While the exact numbers change by year, here are the types of pins you will find on almost every 3S-FE ECU diagram. Note: Always verify these against the specific PDF for your year. 3s-fe ecu pinout pdf
The official source for factory service manuals (FSM). The Toyota 3S-FE, a staple of the Celica,
(Continue for all 26 pins if desired – above is illustrative) Note: Always verify these against the specific PDF
If you are working on a JDM-spec engine or a specific chassis like the ST202 Celica, ensure the pinout matches your ECU's physical plug count (e.g., some older units use a 26P-16P-22P layout).
The ECU's pinout is the specific map of its electrical connectors, where each pin is assigned to a vital sensor or actuator. For the standard 3S-FE (often seen in 1995–1997 RAV4 models), the ECU typically features a three-connector setup: