Pinout Values and Diagnostic Parameters

ECU Testing:

The Mazda Engine Signal Monitor (#49 9200 162) is utilized to check ECU terminal voltages. This tool inspects individual terminal voltages as selected with the monitor switch. A high impedance volt/ohm meter can also be used to check these voltages. Aftermarket test units are available that will read ECU terminal voltages when connected with proper adapters. Conduct tests with engine at operating temperature unless instructed otherwise.

TESTING WITH SIGNAL MONITOR

1. Connect signal monitor between ECU and wiring harness using correct adapter (#49 G018 903).

NOTE: Use adapter connector "A" to measure voltage at terminals 1A through 1V and 3A through 3Z. Use connector "B" to measure at terminals 2A through 2P.

2. Place cover sheet on signal monitor face (#49 G018 904, 64 pin side).
3. Turn selector and monitor switches to select desired terminal number and measure voltage.
4. If any terminal voltage is incorrect, check the input or output device and related wiring. Only replace an ECU if other possible causes of abnormal voltages are eliminated.

CAUTION: Never apply voltage to terminals "A" and "B."

ECU TESTING PRECAUTIONS

1. Never push circuit tester probes into connectors from ECU side.
2. Before replacing an ECU, check components, wiring harnesses and terminal contacts if terminal voltage readings are incorrect. Repair as needed and recheck voltage readings.

ECU PIN VOLTAGE CHART

PART 1

ECU Pin Voltage Chart (Part 1):

PART 2

ECU Pin Voltage Chart (Part 2):

PART 3

ECU Pin Voltage Chart (Part 3):

DECHOKE CONTROL SYSTEM

To verify operation of the Dechoke Control System, depress accelerator pedal fully and turn ignition switch to "START" (engine cranking). Engine should not start until pedal is released.