Terminal Voltage (MT) — ECU Connector

Z-34spec tableUnverified

MT (manual transmission) terminal-voltage table; A/T values referenced for terminals 1V, 1W (inhibitor switch). Canadian/US distinctions not called out here.

Continued from Z-33

MT

Terminal voltage table for the engine control unit (ECU) connector pins on manual-transmission (MT) vehicles. Each row gives a terminal number, the component it connects to, the abnormal voltage observed, and the possible cause(s) when that abnormal voltage is present. Reference notes point to wiring-diagram pages (e.g. F-41, F-43, F-49) for follow-up tests.

Terminal Voltage — MT (ECU connector, terminals 1A–1S)

Terminal	Connection to	Abnormal voltage	Possible cause
1A	Battery	Always approx. 0V (Battery O[?])	ROOM 10A fuse blown; Open circuit in wiring from ROOM 10A fuse to ECU terminal 1A
1B	Main relay	Always approx. 0V	Main relay malfunction (Refer to page F-1[?]); Open circuit in wiring from main relay to ECU terminal 1B
1C	Ignition switch (Start position)	Always approx. 0V	Open circuit in wiring from starter interlock switch to ECU terminal 1C
1D	Self Diagnosis Checker (monitor lamp)	Always approx. 0V; Open circuit in wiring from main relay to diagnosis connector terminal MEN to ECU terminal 1D	Poor connection at ECU connector; ECU malfunction
1D	(continued)	Always approx. 0V	Poor connection at ECU connector; ECU malfunction
1E	Instrument cluster (engine check lamp)	Always approx. 0V (MIL, check ON)	Short circuit in wiring from combination meter to ECU terminal 1E; ECU malfunction
1F	Self Diagnosis Checker (Code No.)	Always below 2.5V (No display on Self Diagnosis Checker)	Open circuit in wiring from combination meter to ECU terminal 1F; Poor connection at ECU connector
1F	(continued — at 1.96" lit displayed and signal)	Always below 2.5V	Main relay malfunction (Refer to page F-1[?]); Open in wiring from main relay to diagnosis connector terminal TEN to ECU terminal 1F
1G	Ignitor	Always approx. 0V	Poor connection at ECU connector; ECU malfunction
1H	A/C relay	Always approx. 2.5V (A/C does not operate)	A/C relay malfunction (Refer to page L-[?]); Open circuit in wiring from A/C relay coil to ECU terminal 1H; ECU malfunction
1H	(continued)	Always below 2.5V (A/C OFF but A/C operates)	Short circuit in wiring from A/C relay to ECU terminal 1H; ECU malfunction
1I	Diagnosis connector (terminal TEN)	Always approx. 12V	Short circuit in wiring from ECU terminal 1I to diagnosis connector terminal TEN; Open circuit in wiring from diagnosis connector to ECU terminal 1I; Poor connection at ECU connector
1J	Throttle sensor (Idle terminal)	Always approx. 12V	Throttle sensor misadjustment (Refer to page F-1[?]); Open in wiring from throttle sensor to ECU terminal 1J; Open circuit in wiring from throttle sensor to ground; ECU malfunction
1K	Stoplight switch	Always approx. 12V (Stoplights ON)	Open circuit in wiring from stoplight switch to ECU terminal 1K
1L	P/N pressure switch	Always approx. 12V	Short circuit in wiring from ECU terminal 1L to P/N pressure switch; Open circuit in wiring from P/N pressure switch to ECU terminal 1L; ECU malfunction
1M	A/C amplifier	Always approx. 0V (with blower switch ON)	A/C switch malfunction (Refer to page U-[?]); Short circuit in wiring from ECU terminal 1M to A/C switch; ECU malfunction
1N	Fan switch	Always approx. 12V (Cooling fan ON)	A/C relay malfunction (Refer to page L-[?]); Open circuit in wiring from A/C relay to ECU terminal 1N; ECU malfunction
1S	Blower control switch (Blower ON)	Always approx. 12V (Blower ON)	Short circuit in wiring from blower control switch to ECU terminal 1S; ECU malfunction

Connection toBattery

Abnormal voltageAlways approx. 0V (Battery O[?])

Possible causeROOM 10A fuse blown; Open circuit in wiring from ROOM 10A fuse to ECU terminal 1A

Connection toMain relay

Abnormal voltageAlways approx. 0V

Possible causeMain relay malfunction (Refer to page F-1[?]); Open circuit in wiring from main relay to ECU terminal 1B

Connection toIgnition switch (Start position)

Abnormal voltageAlways approx. 0V

Possible causeOpen circuit in wiring from starter interlock switch to ECU terminal 1C

Connection toSelf Diagnosis Checker (monitor lamp)

Abnormal voltageAlways approx. 0V; Open circuit in wiring from main relay to diagnosis connector terminal MEN to ECU terminal 1D

Possible causePoor connection at ECU connector; ECU malfunction

Connection to(continued)

Abnormal voltageAlways approx. 0V

Possible causePoor connection at ECU connector; ECU malfunction

Connection toInstrument cluster (engine check lamp)

Abnormal voltageAlways approx. 0V (MIL, check ON)

Possible causeShort circuit in wiring from combination meter to ECU terminal 1E; ECU malfunction

Connection toSelf Diagnosis Checker (Code No.)

Abnormal voltageAlways below 2.5V (No display on Self Diagnosis Checker)

Possible causeOpen circuit in wiring from combination meter to ECU terminal 1F; Poor connection at ECU connector

Connection to(continued — at 1.96" lit displayed and signal)

Abnormal voltageAlways below 2.5V

Possible causeMain relay malfunction (Refer to page F-1[?]); Open in wiring from main relay to diagnosis connector terminal TEN to ECU terminal 1F

Connection toIgnitor

Abnormal voltageAlways approx. 0V

Possible causePoor connection at ECU connector; ECU malfunction

Connection toA/C relay

Abnormal voltageAlways approx. 2.5V (A/C does not operate)

Possible causeA/C relay malfunction (Refer to page L-[?]); Open circuit in wiring from A/C relay coil to ECU terminal 1H; ECU malfunction

Connection to(continued)

Abnormal voltageAlways below 2.5V (A/C OFF but A/C operates)

Possible causeShort circuit in wiring from A/C relay to ECU terminal 1H; ECU malfunction

Connection toDiagnosis connector (terminal TEN)

Abnormal voltageAlways approx. 12V

Possible causeShort circuit in wiring from ECU terminal 1I to diagnosis connector terminal TEN; Open circuit in wiring from diagnosis connector to ECU terminal 1I; Poor connection at ECU connector

Connection toThrottle sensor (Idle terminal)

Abnormal voltageAlways approx. 12V

Possible causeThrottle sensor misadjustment (Refer to page F-1[?]); Open in wiring from throttle sensor to ECU terminal 1J; Open circuit in wiring from throttle sensor to ground; ECU malfunction

Connection toStoplight switch

Abnormal voltageAlways approx. 12V (Stoplights ON)

Possible causeOpen circuit in wiring from stoplight switch to ECU terminal 1K

Connection toP/N pressure switch

Abnormal voltageAlways approx. 12V

Possible causeShort circuit in wiring from ECU terminal 1L to P/N pressure switch; Open circuit in wiring from P/N pressure switch to ECU terminal 1L; ECU malfunction

Connection toA/C amplifier

Abnormal voltageAlways approx. 0V (with blower switch ON)

Possible causeA/C switch malfunction (Refer to page U-[?]); Short circuit in wiring from ECU terminal 1M to A/C switch; ECU malfunction

Connection toFan switch

Abnormal voltageAlways approx. 12V (Cooling fan ON)

Possible causeA/C relay malfunction (Refer to page L-[?]); Open circuit in wiring from A/C relay to ECU terminal 1N; ECU malfunction

Connection toBlower control switch (Blower ON)

Abnormal voltageAlways approx. 12V (Blower ON)

Possible causeShort circuit in wiring from blower control switch to ECU terminal 1S; ECU malfunction

Terminal Voltage — MT (ECU connector, terminals 1T–2Z)

Terminal	Connection to	Abnormal voltage	Possible cause
1T	Headlight switch (Headlights ON)	Always approx. 0V	Open in short circuit in wiring from headlight relay to ECU terminal 1T
1V	Neutral switch / Clutch switch (MT)	Always approx. 0V (M/T)	Neutral switch malfunction (Refer to page F-1[?]); Clutch switch malfunction (Refer to page F-1[?]); Open circuit in wiring from neutral or clutch switch to ECU terminal 1V
1V	(continued — AAT)	Always approx. 12V (A/T)	Neutral switch malfunction (Refer to page F-1[?]); Open circuit in wiring from neutral switch (P/N range) to ECU terminal 1V; Poor connection at ECU connector
1W	Inhibitor switch (A/T)	Always approx. 0V	Inhibitor switch malfunction (Refer to Section [?]); Open circuit in wiring from inhibitor switch to ECU terminal 1W
2A 2B 2C 2D	Ground	More than 0V	Poor contact at ground terminal; Open circuit in wiring from ECU to ground
2E	Crank angle sensor (Ne signal)	Always approx. 0V	Refer to Code No.[?] troubleshooting (Refer to page F-43)
2F	Crank angle sensor (G signal)	Always approx. 0V	Refer to Code No.[?] troubleshooting (Refer to page F-49)
2G	Ground	Always approx. 0V	Open circuit in wiring from ECU terminal 2G to ground
2H	Front air Canister	—	—
2I	Igniter	Always approx. 0V	Refer to Code No. 2 troubleshooting (Refer to page F-41)
2J	Airflow meter	Always approx. 0V	Short circuit in wiring from ECU terminal 2J to airflow meter; Open circuit in wiring from ECU terminal 2J to airflow meter; ECU malfunction
2J	(continued)	Below 4 3V or above 5.5V	ECU malfunction
2K	Throttle sensor (Power terminal/[?] left)	Always approx. 0V	Throttle sensor malfunction (Refer to page F-[?]); Open in wiring from ECU terminal 2K to throttle sensor; Poor connection at ECU connector
2K	(continued)	Always above 5.0V	ECU malfunction
2L	Throttle sensor	Always approx. 0V	Throttle sensor misadjustment (Refer to page F-1[?]); Open in wiring from throttle sensor to ECU terminal 2L; Open circuit in wiring from throttle sensor to ECU terminal 2L; ECU malfunction
2N	Oxygen sensor	Always approx. 0V	Throttle sensor misadjustment
2N	(continued)	0V after warming up	Refer to Code No.15 troubleshooting (Refer to page F-49)
2N	(continued)	Always approx. 1.5V after warming up	Refer to Code No.15 troubleshooting (Refer to page F-49)
2P	Airflow meter	Always approx. 1V or above	Refer to Code No.16 troubleshooting (Refer to page F-49)
2P	(continued)	Always approx. 1V or above	Refer to Code No.16 troubleshooting (Refer to page F-49)
2T	Water thermosensor	Always approx. 0V	Refer to Code No.16 troubleshooting (Refer to page F-49); Water thermosensor malfunction (Refer to page F-1[?])
2U	Injector	Always approx. 0V	Main relay malfunction (Refer to page F-1[?]); Open in short circuit in wiring from main relay to ECU terminal 2U; ECU malfunction
2V	ISC valve (Purge control)	Always approx. 0V	Refer to Code No.34 troubleshooting (Refer to page F-49); ISC valve malfunction (Refer to page F-1[?])
2W	Solenoid valve (Purge control)	Always approx. 0V	Solenoid valve (Purge control) malfunction (Refer to page F-1[?])
2Z	VAT signal (purge control)	—	[?] malfunction

Connection toHeadlight switch (Headlights ON)

Abnormal voltageAlways approx. 0V

Possible causeOpen in short circuit in wiring from headlight relay to ECU terminal 1T

Connection toNeutral switch / Clutch switch (MT)

Abnormal voltageAlways approx. 0V (M/T)

Possible causeNeutral switch malfunction (Refer to page F-1[?]); Clutch switch malfunction (Refer to page F-1[?]); Open circuit in wiring from neutral or clutch switch to ECU terminal 1V

Connection to(continued — AAT)

Abnormal voltageAlways approx. 12V (A/T)

Possible causeNeutral switch malfunction (Refer to page F-1[?]); Open circuit in wiring from neutral switch (P/N range) to ECU terminal 1V; Poor connection at ECU connector

Connection toInhibitor switch (A/T)

Abnormal voltageAlways approx. 0V

Possible causeInhibitor switch malfunction (Refer to Section [?]); Open circuit in wiring from inhibitor switch to ECU terminal 1W

2A 2B 2C 2D

Connection toGround

Abnormal voltageMore than 0V

Possible causePoor contact at ground terminal; Open circuit in wiring from ECU to ground

Connection toCrank angle sensor (Ne signal)

Abnormal voltageAlways approx. 0V

Possible causeRefer to Code No.[?] troubleshooting (Refer to page F-43)

Connection toCrank angle sensor (G signal)

Abnormal voltageAlways approx. 0V

Possible causeRefer to Code No.[?] troubleshooting (Refer to page F-49)

Connection toGround

Abnormal voltageAlways approx. 0V

Possible causeOpen circuit in wiring from ECU terminal 2G to ground

Connection toFront air Canister

Abnormal voltage—

Possible cause—

Connection toIgniter

Abnormal voltageAlways approx. 0V

Possible causeRefer to Code No. 2 troubleshooting (Refer to page F-41)

Connection toAirflow meter

Abnormal voltageAlways approx. 0V

Possible causeShort circuit in wiring from ECU terminal 2J to airflow meter; Open circuit in wiring from ECU terminal 2J to airflow meter; ECU malfunction

Connection to(continued)

Abnormal voltageBelow 4 3V or above 5.5V

Possible causeECU malfunction

Connection toThrottle sensor (Power terminal/[?] left)

Abnormal voltageAlways approx. 0V

Possible causeThrottle sensor malfunction (Refer to page F-[?]); Open in wiring from ECU terminal 2K to throttle sensor; Poor connection at ECU connector

Connection to(continued)

Abnormal voltageAlways above 5.0V

Possible causeECU malfunction

Connection toThrottle sensor

Abnormal voltageAlways approx. 0V

Possible causeThrottle sensor misadjustment (Refer to page F-1[?]); Open in wiring from throttle sensor to ECU terminal 2L; Open circuit in wiring from throttle sensor to ECU terminal 2L; ECU malfunction

Connection toOxygen sensor

Abnormal voltageAlways approx. 0V

Possible causeThrottle sensor misadjustment

Connection to(continued)

Abnormal voltage0V after warming up

Possible causeRefer to Code No.15 troubleshooting (Refer to page F-49)

Connection to(continued)

Abnormal voltageAlways approx. 1.5V after warming up

Possible causeRefer to Code No.15 troubleshooting (Refer to page F-49)

Connection toAirflow meter

Abnormal voltageAlways approx. 1V or above

Possible causeRefer to Code No.16 troubleshooting (Refer to page F-49)

Connection to(continued)

Abnormal voltageAlways approx. 1V or above

Possible causeRefer to Code No.16 troubleshooting (Refer to page F-49)

Connection toWater thermosensor

Abnormal voltageAlways approx. 0V

Possible causeRefer to Code No.16 troubleshooting (Refer to page F-49); Water thermosensor malfunction (Refer to page F-1[?])

Connection toInjector

Abnormal voltageAlways approx. 0V

Possible causeMain relay malfunction (Refer to page F-1[?]); Open in short circuit in wiring from main relay to ECU terminal 2U; ECU malfunction

Connection toISC valve (Purge control)

Abnormal voltageAlways approx. 0V

Possible causeRefer to Code No.34 troubleshooting (Refer to page F-49); ISC valve malfunction (Refer to page F-1[?])

Connection toSolenoid valve (Purge control)

Abnormal voltageAlways approx. 0V

Possible causeSolenoid valve (Purge control) malfunction (Refer to page F-1[?])

Connection toVAT signal (purge control)

Abnormal voltage—

Possible cause[?] malfunction

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Terminal Voltage (MT) — ECU Connector

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Terminal Voltage — MT (ECU connector, terminals 1A–1S)

Terminal Voltage — MT (ECU connector, terminals 1T–2Z)

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