Terminal Voltage (AT) — ECU Connector

Z-35spec tableUnverified

AT (automatic transmission) terminal-voltage table. Some Federal/Canada distinctions noted at terminal 2H ground. Self-Diagnosis Checker and System Selector test-switch position required for several measurements.

Continued from Z-34

AT

Terminal voltage table for the ECU connector pins on automatic-transmission (AT) vehicles. Columns: Terminal, Input/Output direction (with O marking active direction), Connection to, Test condition, Voltage, and Remark. The right-hand sub-table covers ground and sensor terminals (2A–2Z).

Terminal Voltage — AT (ECU connector, terminals 1A–1W)

Terminal	Input	Output	Connection to	Test condition	Voltage	Remark
1A	—	—	Battery	Constant	Approx. 12V	For backup
1B	O	—	Main relay	Ignition switch OFF	Approx. 0V
1B	O	—	Main relay	Ignition switch ON	Approx. 12V
1C	O	—	Ignition switch (Start position)	While cranking	Approx. 12V
1C	O	—	Ignition switch (Start position)	Other conditions	Approx. 0V
1D	O	—	Self-Diagnosis Checker (Monitor lamp)	Test switch at "SELF-TEST"; Lamp illuminated for 3 sec. after ignition switch OFF→ON	Approx. 5V	With Self-Diagnosis Checker and System Selector
1D	O	—	Self-Diagnosis Checker (Monitor lamp)	Test switch not in "O[?] MONITOR" at idle; Monitor lamp illuminated	Approx. 5V
1D	O	—	Self-Diagnosis Checker (Monitor lamp)	Test switch at "O[?] MONITOR" at idle; Monitor lamp not illuminated	Approx. 0V
1E	—	O	Malfunction indicator lamp	Lamp illuminated after 3 sec; Lamp not illuminated after 3 sec	Approx. 12V; Below 2.5V	With System Selector test switch at "SELF-TEST"
1E	—	O	Malfunction indicator lamp	Lamp not illuminated	Below 2.5V
1F	O	—	Self-Diagnosis Checker (Code number)	Buzzer sounded for 3 sec. after ignition switch OFF→ON; Buzzer not sounded after 3 sec; Buzzer sounded	Below 2.5V; Approx. 2.5V	With Self-Diagnosis Checker and System Selector test switch at "SELF-TEST"
1F	O	—	Self-Diagnosis Checker (Code number)	Buzzer not sounded	Approx. 0V
1G	—	O	Igniter	Ignition switch ON	Approx. 12V
1G	—	O	Igniter	Idle	Approx. 0V
1H	—	O	Igniter	Ignition switch ON at idle; Idle	Approx. 12V; Approx. 0V
1I	—	—	—	—	—
1J	—	O	A/C relay	Ignition switch ON at idle; A/C switch ON at idle; A/C switch OFF at idle	Approx. 12V; Below 2.5V; Approx. 12V
1K	O	—	Diagnosis connector	System Selector test switch at "SELF-TEST"	Approx. 0V
1L	—	—	—	—	—
1M	—	—	—	—	—
1N	O	—	Throttle sensor (Idle position)	Accelerator pedal released; Accelerator pedal depressed	Approx. 0V; Approx. 12V	Ignition switch ON
1O	O	—	Stoplight switch	Brake pedal released; Brake pedal depressed	Approx. 0V; Approx. 12V
1P	O	—	P/S pressure switch	P/S ON (at idle); P/S OFF (at idle)	Approx. 12V; Approx. 0V
1Q	O	—	A/C switch	A/C switch ON (with blower switch ON); A/C switch OFF (with blower switch ON)	Below 2.5V; Approx. 12V	Blower motor ON
1R	O	—	Fan switch	Fan switch ON (engine coolant temperature above 97°C (207°F)) or diagnosis connector grounded; Fan switch OFF (engine coolant temperature below); Fan not operating (idle)	Approx. 0V; Approx. 12V; Approx. 12V
1S	O	—	Blower control switch	Blower control switch at med, high or super high (Blower motor ON); Blower control switch OFF or at low	Below 2.5V; Approx. 12V	Ignition switch ON
1T	—	—	—	—	—
1U	O	—	Headlight switch	Headlights ON (Tail, parking, low beam, high beam); Headlights OFF	Approx. 12V; Approx. 0V
1V	O	—	Neutral switch / clutch switch (M/T)	Neutral position or clutch pedal depressed; Other conditions	Below 2.5V; Approx. 12V
1W	O	—	Inhibitor switch (A/T)	N or P range; Other ranges	Below 2.5V; Approx. 12V

Input—

Output—

Connection toBattery

Test conditionConstant

VoltageApprox. 12V

RemarkFor backup

InputO

Output—

Connection toMain relay

Test conditionIgnition switch OFF

VoltageApprox. 0V

Remark

InputO

Output—

Connection toMain relay

Test conditionIgnition switch ON

VoltageApprox. 12V

Remark

InputO

Output—

Connection toIgnition switch (Start position)

Test conditionWhile cranking

VoltageApprox. 12V

Remark

InputO

Output—

Connection toIgnition switch (Start position)

Test conditionOther conditions

VoltageApprox. 0V

Remark

InputO

Output—

Connection toSelf-Diagnosis Checker (Monitor lamp)

Test conditionTest switch at "SELF-TEST"; Lamp illuminated for 3 sec. after ignition switch OFF→ON

VoltageApprox. 5V

RemarkWith Self-Diagnosis Checker and System Selector

InputO

Output—

Connection toSelf-Diagnosis Checker (Monitor lamp)

Test conditionTest switch not in "O[?] MONITOR" at idle; Monitor lamp illuminated

VoltageApprox. 5V

Remark

InputO

Output—

Connection toSelf-Diagnosis Checker (Monitor lamp)

Test conditionTest switch at "O[?] MONITOR" at idle; Monitor lamp not illuminated

VoltageApprox. 0V

Remark

Input—

OutputO

Connection toMalfunction indicator lamp

Test conditionLamp illuminated after 3 sec; Lamp not illuminated after 3 sec

VoltageApprox. 12V; Below 2.5V

RemarkWith System Selector test switch at "SELF-TEST"

Input—

OutputO

Connection toMalfunction indicator lamp

Test conditionLamp not illuminated

VoltageBelow 2.5V

Remark

InputO

Output—

Connection toSelf-Diagnosis Checker (Code number)

Test conditionBuzzer sounded for 3 sec. after ignition switch OFF→ON; Buzzer not sounded after 3 sec; Buzzer sounded

VoltageBelow 2.5V; Approx. 2.5V

RemarkWith Self-Diagnosis Checker and System Selector test switch at "SELF-TEST"

InputO

Output—

Connection toSelf-Diagnosis Checker (Code number)

Test conditionBuzzer not sounded

VoltageApprox. 0V

Remark

Input—

OutputO

Connection toIgniter

Test conditionIgnition switch ON

VoltageApprox. 12V

Remark

Input—

OutputO

Connection toIgniter

Test conditionIdle

VoltageApprox. 0V

Remark

Input—

OutputO

Connection toIgniter

Test conditionIgnition switch ON at idle; Idle

VoltageApprox. 12V; Approx. 0V

Remark

Input—

Output—

Connection to—

Test condition—

Voltage—

Remark

Input—

OutputO

Connection toA/C relay

Test conditionIgnition switch ON at idle; A/C switch ON at idle; A/C switch OFF at idle

VoltageApprox. 12V; Below 2.5V; Approx. 12V

Remark

InputO

Output—

Connection toDiagnosis connector

Test conditionSystem Selector test switch at "SELF-TEST"

VoltageApprox. 0V

Remark

Input—

Output—

Connection to—

Test condition—

Voltage—

Remark

Input—

Output—

Connection to—

Test condition—

Voltage—

Remark

InputO

Output—

Connection toThrottle sensor (Idle position)

Test conditionAccelerator pedal released; Accelerator pedal depressed

VoltageApprox. 0V; Approx. 12V

RemarkIgnition switch ON

InputO

Output—

Connection toStoplight switch

Test conditionBrake pedal released; Brake pedal depressed

VoltageApprox. 0V; Approx. 12V

Remark

InputO

Output—

Connection toP/S pressure switch

Test conditionP/S ON (at idle); P/S OFF (at idle)

VoltageApprox. 12V; Approx. 0V

Remark

InputO

Output—

Connection toA/C switch

Test conditionA/C switch ON (with blower switch ON); A/C switch OFF (with blower switch ON)

VoltageBelow 2.5V; Approx. 12V

RemarkBlower motor ON

InputO

Output—

Connection toFan switch

Test conditionFan switch ON (engine coolant temperature above 97°C (207°F)) or diagnosis connector grounded; Fan switch OFF (engine coolant temperature below); Fan not operating (idle)

VoltageApprox. 0V; Approx. 12V; Approx. 12V

Remark

InputO

Output—

Connection toBlower control switch

Test conditionBlower control switch at med, high or super high (Blower motor ON); Blower control switch OFF or at low

VoltageBelow 2.5V; Approx. 12V

RemarkIgnition switch ON

Input—

Output—

Connection to—

Test condition—

Voltage—

Remark

InputO

Output—

Connection toHeadlight switch

Test conditionHeadlights ON (Tail, parking, low beam, high beam); Headlights OFF

VoltageApprox. 12V; Approx. 0V

Remark

InputO

Output—

Connection toNeutral switch / clutch switch (M/T)

Test conditionNeutral position or clutch pedal depressed; Other conditions

VoltageBelow 2.5V; Approx. 12V

Remark

InputO

Output—

Connection toInhibitor switch (A/T)

Test conditionN or P range; Other ranges

VoltageBelow 2.5V; Approx. 12V

Remark

Terminal Voltage — AT (ECU connector, terminals 2A–2Z)

Terminal	Input	Output	Connection to	Test condition	Voltage	Remark
2A	—	—	Ground (Injector)	Constant	Approx. 12V
2B	—	—	Ground (Output)	Constant	0V
2C	—	—	Ground (CPU)	Constant	0V
2D	—	—	Ground (Input)	Constant	0V
2E	O	—	Crank angle sensor (Ne signal)	Ignition switch ON; Idle	0V or 5V; Approx. 2V
2F	—	—	—	—	—
2G	O	—	Crank angle sensor (G signal)	Ignition switch ON; Idle	0V or 5V; Approx. 1.5V
2H	—	—	Ground	Federal and Canada spec.	0V
2I	—	O	Igniter	Ignition switch ON; Idle	Approx. 0.5V; Approx. 12V
2J	—	—	—	—	—
2K	O	—	Airflow meter	Constant	4.5—5.5V
2L	O	—	Throttle sensor (Power terminal)	Accelerator pedal released	Approx. 5V
2M	O	—	Throttle sensor	Accelerator pedal released; Accelerator pedal fully depressed	0V; Approx. 4.0V
2N	O	—	Oxygen sensor	Ignition switch ON; Idle (Cold engine); Idle (After warm-up); Increase engine speed (After warm-up); Deceleration	0V; 0V; 0.5—1V; 0—0.4V
2O	O	—	Airflow meter (intake air thermosensor)	At 20°C (68°F)	Approx. 3.3V
2P	O	—	Airflow sensor (intake air thermosensor)	At 20°C (68°F)	Approx. 2.5V
2Q	O	—	Water thermosensor	Engine coolant temperature 20°C (68°F)	Approx. 2.5V
2Q	O	—	Water thermosensor	After warm-up	Approx. 0.4V
2R	—	—	—	—	—
2S	—	—	—	—	—
2T	—	—	—	—	—
2U	O	—	Injector (No.1, 3) / (No.2, 4)	Idle; Deceleration from 3,000 rpm to 1,900 rpm (After warm-up)	Approx. 12V; Approx. 12V*	* Engine Signal Monitor: Green lamp and lights flash
2V	O	—	ISC valve	Ignition switch ON; Idle	Approx. 7V; Approx. 12V*
2X	O	—	Solenoid valve (Purge control)	Ignition switch ON; Idle	Approx. 12V; Approx. 12V*
2Z	—	O	4WT control unit	Ignition switch ON	Approx. 0V

Input—

Output—

Connection toGround (Injector)

Test conditionConstant

VoltageApprox. 12V

Remark

Input—

Output—

Connection toGround (Output)

Test conditionConstant

Voltage0V

Remark

Input—

Output—

Connection toGround (CPU)

Test conditionConstant

Voltage0V

Remark

Input—

Output—

Connection toGround (Input)

Test conditionConstant

Voltage0V

Remark

InputO

Output—

Connection toCrank angle sensor (Ne signal)

Test conditionIgnition switch ON; Idle

Voltage0V or 5V; Approx. 2V

Remark

Input—

Output—

Connection to—

Test condition—

Voltage—

Remark

InputO

Output—

Connection toCrank angle sensor (G signal)

Test conditionIgnition switch ON; Idle

Voltage0V or 5V; Approx. 1.5V

Remark

Input—

Output—

Connection toGround

Test conditionFederal and Canada spec.

Voltage0V

Remark

Input—

OutputO

Connection toIgniter

Test conditionIgnition switch ON; Idle

VoltageApprox. 0.5V; Approx. 12V

Remark

Input—

Output—

Connection to—

Test condition—

Voltage—

Remark

InputO

Output—

Connection toAirflow meter

Test conditionConstant

Voltage4.5—5.5V

Remark

InputO

Output—

Connection toThrottle sensor (Power terminal)

Test conditionAccelerator pedal released

VoltageApprox. 5V

Remark

InputO

Output—

Connection toThrottle sensor

Test conditionAccelerator pedal released; Accelerator pedal fully depressed

Voltage0V; Approx. 4.0V

Remark

InputO

Output—

Connection toOxygen sensor

Test conditionIgnition switch ON; Idle (Cold engine); Idle (After warm-up); Increase engine speed (After warm-up); Deceleration

Voltage0V; 0V; 0.5—1V; 0—0.4V

Remark

InputO

Output—

Connection toAirflow meter (intake air thermosensor)

Test conditionAt 20°C (68°F)

VoltageApprox. 3.3V

Remark

InputO

Output—

Connection toAirflow sensor (intake air thermosensor)

Test conditionAt 20°C (68°F)

VoltageApprox. 2.5V

Remark

InputO

Output—

Connection toWater thermosensor

Test conditionEngine coolant temperature 20°C (68°F)

VoltageApprox. 2.5V

Remark

InputO

Output—

Connection toWater thermosensor

Test conditionAfter warm-up

VoltageApprox. 0.4V

Remark

Input—

Output—

Connection to—

Test condition—

Voltage—

Remark

Input—

Output—

Connection to—

Test condition—

Voltage—

Remark

Input—

Output—

Connection to—

Test condition—

Voltage—

Remark

InputO

Output—

Connection toInjector (No.1, 3) / (No.2, 4)

Test conditionIdle; Deceleration from 3,000 rpm to 1,900 rpm (After warm-up)

VoltageApprox. 12V; Approx. 12V*

Remark* Engine Signal Monitor: Green lamp and lights flash

InputO

Output—

Connection toISC valve

Test conditionIgnition switch ON; Idle

VoltageApprox. 7V; Approx. 12V*

Remark

InputO

Output—

Connection toSolenoid valve (Purge control)

Test conditionIgnition switch ON; Idle

VoltageApprox. 12V; Approx. 12V*

Remark

Input—

OutputO

Connection to4WT control unit

Test conditionIgnition switch ON

VoltageApprox. 0V

Remark

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Terminal Voltage (AT) — ECU Connector

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Terminal Voltage — AT (ECU connector, terminals 2A–2Z)

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