ECU for 1989 Acura Integra Manual

The ECU (Engine Control Unit) for the 1989 Acura Integra with manual transmission is a critical engine management component that controls fuel injection, ignition timing, and various engine parameters. This system features OBD-I diagnostics, adaptive learning capabilities, and interfaces with sensors including MAP, TPS, coolant temperature, and oxygen sensors. Below are key sections covering specifications, installation, troubleshooting, programming, and maintenance.

1. ECU Specifications 2. Installation Procedures 3. Diagnostic Codes 4. Sensor Connections 5. Programming & Calibration 6. Troubleshooting Guide 7. Maintenance Schedule 8. Wiring Diagrams 9. Performance Tuning 10. Regulatory Information 11. Technical Support

ECU Specifications

Key components: Main processor unit, connector harness, diagnostic port, sensor interfaces.

Feature	Description
ECU Model	PGM-FI System ECU
Compatibility	1989 Acura Integra Manual Transmission
Processor Type	16-bit microcontroller
Memory	64KB ROM, 2KB RAM
Diagnostic System	OBD-I with blink code output
Input Voltage	12V DC vehicle system
Operating Temp	-40°C to 85°C (-40°F to 185°F)
Connector Type	26-pin waterproof harness
Communication	Serial data interface
Mounting Location	Passenger side kick panel

Installation Procedures

Proper installation ensures optimal ECU performance and engine operation.

Disconnect battery: Remove negative terminal before beginning work.
Locate existing ECU: Passenger side interior kick panel area.
Remove connector: Press release tab and disconnect harness.
Install new ECU: Secure in mounting bracket with provided hardware.
Reconnect harness: Ensure proper alignment and secure connection.
Reconnect battery and test: Start engine and check for error codes.

WARNING! Always disconnect battery before ECU installation to prevent electrical damage.

Diagnostic Codes

OBD-I diagnostic codes accessed via service connector under dashboard.

Locate service connector: Under driver's side dashboard.
Bridge terminals: Connect service connector pins with jumper wire.
Read blink codes: Count check engine light flashes for code identification.
Interpret codes: Refer to code chart for specific fault identification.
Clear codes: Disconnect battery for 10 minutes after repairs.

Common Codes: 1 - Oxygen sensor, 4 - Crank angle sensor, 7 - Throttle position sensor

Sensor Connections

MAP Sensor: Manifold Absolute Pressure monitoring
TPS: Throttle Position Sensor for throttle input
Coolant Temp Sensor: Engine temperature monitoring
Oxygen Sensor: Air/fuel ratio feedback
Crank Angle Sensor: Ignition timing reference
Vehicle Speed Sensor: Manual transmission speed input
Injector Drivers: Fuel injector control circuits
Ignition Control: Distributor ignition timing

Programming & Calibration

ECU features adaptive learning and basic calibration capabilities.

Reset Procedure: Disconnect battery for 10 minutes to clear adaptive memory.

Idle Learn Procedure: Start engine, allow to reach operating temperature, run at 3000 RPM for 5 minutes, then idle for 5 minutes.

Base Settings: Fuel trim, ignition advance, idle speed control programmed at factory.

Troubleshooting Guide

Common ECU-related issues and solutions for 1989 Integra manual transmission.

Symptom	Possible Cause	Corrective Action
No start condition	ECU power/main relay	Check ECU power supply and main relay operation
Poor fuel economy	Oxygen sensor/ECU calibration	Test oxygen sensor; reset ECU adaptive memory
Rough idle	IAC valve/ECU programming	Clean IAC valve; perform idle learn procedure
Check engine light	Sensor faults/ECU codes	Retrieve diagnostic codes; test indicated sensors
Performance issues	Ignition timing/ECU maps	Verify base timing; check for ECU communication errors

Maintenance Schedule

Regular maintenance ensures long-term ECU reliability and performance.

Monthly: Check for stored diagnostic codes
Every 6 months: Inspect ECU connectors for corrosion
Annual: Verify ECU mounting security and harness integrity
Every 2 years: Check ECU ground connections and clean if necessary
As needed: Reset adaptive memory after major engine service

Tip: Keep ECU area clean and dry to prevent moisture damage.

Wiring Diagrams

ECU pinout and wiring connections for proper installation and troubleshooting.

Key Connections: Power (pins 1,2), Ground (pins 3,4), Injector drivers (pins 5-8), Sensor inputs (pins 9-16), Ignition control (pins 17-18)

Color Codes: Red - power, Black - ground, Green - sensor signals, Blue - output controls

Performance Tuning

Limited tuning capabilities available through factory ECU.

Base timing adjustment: Via distributor rotation within specified range
Fuel pressure: Regulator adjustment affects fuel delivery
Sensor calibration: TPS adjustment for throttle position accuracy
Idle speed: Set via throttle stop screw and IAC valve

WARNING! Significant performance changes require aftermarket ECU replacement.

Regulatory Information

This ECU complies with 1989 EPA emissions standards and California Air Resources Board requirements. System incorporates factory emissions controls and monitoring. Copyright © 1989 Honda Motor Co., Ltd. For technical support, contact Acura customer service or authorized dealerships.

Technical Support

For ECU-related issues and technical assistance:

Service	Contact Information	Availability
Acura Customer Service	1-800-382-2238	Mon-Fri 9am-5pm EST
Technical Documentation	Acura Service Manual	Available at dealerships
Parts Replacement	Authorized Acura Parts	Through dealership network
Online Resources	Acura owner forums	Community technical support

Note: Always consult factory service manual for detailed repair procedures.