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MX-5 Miata NA8 1996-97 (BP-ZE, 1.8, OBD-II) → Emtron KV8 (auto)

MX-5 Miata NA8 1996-97 (BP-ZE, 1.8, OBD-II) — Emtron — KV8
⚠ NOT CHECKED. Don't build from this.
Drawn by Michael Gnankou · Rev 0 · draft · 2026-10-12

Before you start

Not confident with automotive wiring? Have a professional harness builder or tuner do it, or check your work before first power-up. A wiring mistake can damage the ECU, the engine or the car, or start a fire.

Statusdraft · not yet verified: nobody has reported building and running this harness
Open errors1: read the Findings page before cutting any wire
Size of the job54 wires · 10 connectors · 5 part lines
ToolsCrimp and extraction tools for each terminal family (see Connectors) · wire strippers · multimeter · heat gun + heat-shrink
Terminals3-1447221-4
Order of work1. Check every part against the parts list. 2. Cut and label every wire (labels: Export → Wire labels). 3. Crimp and pin connector by connector, ticking the build checklist. 4. Run the bench test with nothing plugged in and the battery disconnected. 5. Only then connect the ECU and power up.

Build checklist

Tick each box as you go. Continuity: meter from end to end, expect under 1 Ω.

WireFromToGaugeColourCutLabelCrimp ACrimp BPin APin BContinuity
W1OEM-4-BSP-14V-10.85☐☐☐☐☐☐☐
W2SP-14V-1KV8-D-10.85☐☐☐☐☐☐☐
W3SP-14V-1KV8-D-20.85☐☐☐☐☐☐☐
W4SP-14V-1KV8-D-200.85☐☐☐☐☐☐☐
W5OEM-4-ASP-GND-10.85☐☐☐☐☐☐☐
W6OEM-4-CSP-GND-10.85☐☐☐☐☐☐☐
W7OEM-4-DSP-GND-10.85☐☐☐☐☐☐☐
W8OEM-4-KSP-GND-10.85☐☐☐☐☐☐☐
W9SP-GND-1KV8-B-340.85☐☐☐☐☐☐☐
W10SP-GND-1KV8-B-90.85☐☐☐☐☐☐☐
W11SP-GND-1KV8-C-10.85☐☐☐☐☐☐☐
W12SP-GND-1KV8-C-260.85☐☐☐☐☐☐☐
W13OEM-3-OSP-0V-10.5☐☐☐☐☐☐☐
W14OEM-4-HSP-0V-10.5☐☐☐☐☐☐☐
W15SP-0V-1KV8-C-170.5☐☐☐☐☐☐☐
W16SP-0V-1KV8-C-250.5☐☐☐☐☐☐☐
W17OEM-3-IKV8-D-210.5☐☐☐☐☐☐☐
W18OEM-4-EKV8-D-40.5☐☐☐☐☐☐☐
W19SP-0V-1KV8-D-50.5☐☐☐☐☐☐☐
W20OEM-4-GKV8-D-60.5☐☐☐☐☐☐☐
W21SP-0V-1KV8-D-70.5☐☐☐☐☐☐☐
W22OEM-4-NKV8-B-260.5☐☐☐☐☐☐☐
W23OEM-4-RKV8-B-270.5☐☐☐☐☐☐☐
W24OEM-4-UKV8-B-10.5☐☐☐☐☐☐☐
W25OEM-4-VKV8-B-20.5☐☐☐☐☐☐☐
W26OEM-4-WKV8-B-30.5☐☐☐☐☐☐☐
W27OEM-4-XKV8-B-40.5☐☐☐☐☐☐☐
W28OEM-3-BKV8-C-20.5☐☐☐☐☐☐☐
W29OEM-3-FKV8-C-30.5☐☐☐☐☐☐☐
W30OEM-3-GKV8-C-40.5☐☐☐☐☐☐☐
W31OEM-1-AKV8-D-90.5☐☐☐☐☐☐☐
W32OEM-1-BKV8-B-140.5☐☐☐☐☐☐☐
W33OEM-1-GKV8-B-150.5☐☐☐☐☐☐☐
W34OEM-1-UKV8-B-160.5☐☐☐☐☐☐☐
W35OEM-3-MKV8-A-100.5☐☐☐☐☐☐☐
W36OEM-1-EKV8-B-170.5☐☐☐☐☐☐☐
W37OEM-4-JKV8-B-100.5☐☐☐☐☐☐☐
W38OEM-4-OKV8-B-110.5☐☐☐☐☐☐☐
W39OEM-4-PKV8-B-120.5☐☐☐☐☐☐☐
W40OEM-4-QKV8-B-130.5☐☐☐☐☐☐☐
W41OEM-4-TKV8-A-110.5☐☐☐☐☐☐☐
W42OEM-3-HKV8-C-50.5☐☐☐☐☐☐☐
W43OEM-3-NKV8-C-60.5☐☐☐☐☐☐☐
W44OEM-3-CKV8-C-70.5☐☐☐☐☐☐☐
W45OEM-3-DKV8-C-80.5☐☐☐☐☐☐☐
W46OEM-3-KKV8-C-90.5☐☐☐☐☐☐☐
W47OEM-3-JKV8-C-100.5☐☐☐☐☐☐☐
W48OEM-1-MKV8-C-270.5☐☐☐☐☐☐☐
W49OEM-1-CKV8-C-280.5☐☐☐☐☐☐☐
W50OEM-1-KKV8-C-290.5☐☐☐☐☐☐☐
W51OEM-1-LKV8-C-300.5☐☐☐☐☐☐☐
W52OEM-1-QKV8-C-310.5☐☐☐☐☐☐☐
W53OEM-3-LKV8-C-320.5☐☐☐☐☐☐☐
W54OEM-3-PKV8-C-330.5☐☐☐☐☐☐☐

Bench test (before first power-up)

Battery disconnected, ECU and every sensor unplugged. Meter on resistance. Each pair below must read open (OL): a reading means a pinched wire, a stray strand or a mis-pinned cavity. Then check continuity of every wire (last column of the build checklist).

#Probe AProbe BExpectWhyReading
1KV8-D-21KV8-B-34open (OL)5 V sensor reference must not touch power ground
2KV8-D-21KV8-C-17open (OL)5 V sensor reference must not touch sensor ground
3KV8-B-34KV8-D-1open (OL)power ground must not touch +12 V supply
4KV8-C-17KV8-D-1open (OL)sensor ground must not touch +12 V supply
5KV8-D-21KV8-D-1open (OL)5 V sensor reference must not touch +12 V supply

If any reading doesn't match, stop and get help before powering up.

Revisions

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Schematic

KV8-AKV8-BKV8-CKV8-DOEM-1OEM-3OEM-4SP-0VSP-14VSP-GND

Connectors

KV8-A

Mating face
KV8-A-11KV8-A-22KV8-A-33KV8-A-44KV8-A-55KV8-A-66KV8-A-77KV8-A-88KV8-A-99KV8-A-10 · Lambda 1 heater −10KV8-A-11 · Lambda 2 heater −11KV8-A-1212KV8-A-1313KV8-A-1414KV8-A-1515KV8-A-16 · Lambda 1 heater +16KV8-A-17 · Lambda 2 heater +17KV8-A-18 · Lambda 1 Nernst cell (Vs)18KV8-A-1919KV8-A-20 · Lambda 2 cal resistor20KV8-A-21 · Lambda 2 Nernst cell (Vs)21KV8-A-22 · Lambda 2 pump cell (Ip)22KV8-A-23 · Lambda 2 virtual ground23KV8-A-24 · Lambda 1 cal resistor24KV8-A-25 · Lambda 1 pump cell (Ip)25KV8-A-26 · Lambda 1 virtual ground26
Wire side
KV8-A-11KV8-A-22KV8-A-33KV8-A-44KV8-A-55KV8-A-66KV8-A-77KV8-A-88KV8-A-99KV8-A-10 · Lambda 1 heater −10KV8-A-11 · Lambda 2 heater −11KV8-A-1212KV8-A-1313KV8-A-1414KV8-A-1515KV8-A-16 · Lambda 1 heater +16KV8-A-17 · Lambda 2 heater +17KV8-A-18 · Lambda 1 Nernst cell (Vs)18KV8-A-1919KV8-A-20 · Lambda 2 cal resistor20KV8-A-21 · Lambda 2 Nernst cell (Vs)21KV8-A-22 · Lambda 2 pump cell (Ip)22KV8-A-23 · Lambda 2 virtual ground23KV8-A-24 · Lambda 1 cal resistor24KV8-A-25 · Lambda 1 pump cell (Ip)25KV8-A-26 · Lambda 1 virtual ground26
CavityFunctionSignalWireColourGauge (mm²)DestinationTerminalSealPlug
1—————————
2—————————
3—————————
4—————————
5—————————
6—————————
7—————————
8—————————
9—————————
10Lambda 1 heater −—W35—0.5OEM-3-M———
11Lambda 2 heater −—W41—0.5OEM-4-T———
12—————————
13—————————
14—————————
15—————————
16Lambda 1 heater +————————
17Lambda 2 heater +————————
18Lambda 1 Nernst cell (Vs)————————
19—————————
20Lambda 2 cal resistor————————
21Lambda 2 Nernst cell (Vs)————————
22Lambda 2 pump cell (Ip)————————
23Lambda 2 virtual ground————————
24Lambda 1 cal resistor————————
25Lambda 1 pump cell (Ip)————————
26Lambda 1 virtual ground————————

KV8-B

Mating face
KV8-B-1 · Injection 11KV8-B-2 · Injection 22KV8-B-3 · Injection 33KV8-B-4 · Injection 44KV8-B-5 · Injection 55KV8-B-6 · Injection 66KV8-B-7 · Injection 77KV8-B-8 · Injection 88KV8-B-9 · ECU ground9KV8-B-10 · Aux 110KV8-B-11 · Aux 211KV8-B-12 · Aux 312KV8-B-13 · Aux 413KV8-B-14 · Aux 514KV8-B-15 · Aux 615KV8-B-16 · Aux 716KV8-B-17 · Aux 817KV8-B-18 · Aux 918KV8-B-19 · Aux 1019KV8-B-20 · Aux 1120KV8-B-21 · Aux 1221KV8-B-22 · Aux 1322KV8-B-23 · Aux 1423KV8-B-24 · Aux 1524KV8-B-25 · Aux 1625KV8-B-26 · Ignition 126KV8-B-27 · Ignition 227KV8-B-28 · Ignition 328KV8-B-29 · Ignition 429KV8-B-30 · Ignition 530KV8-B-31 · Ignition 631KV8-B-32 · Ignition 732KV8-B-33 · Ignition 833KV8-B-34 · ECU ground34
Wire side
KV8-B-1 · Injection 11KV8-B-2 · Injection 22KV8-B-3 · Injection 33KV8-B-4 · Injection 44KV8-B-5 · Injection 55KV8-B-6 · Injection 66KV8-B-7 · Injection 77KV8-B-8 · Injection 88KV8-B-9 · ECU ground9KV8-B-10 · Aux 110KV8-B-11 · Aux 211KV8-B-12 · Aux 312KV8-B-13 · Aux 413KV8-B-14 · Aux 514KV8-B-15 · Aux 615KV8-B-16 · Aux 716KV8-B-17 · Aux 817KV8-B-18 · Aux 918KV8-B-19 · Aux 1019KV8-B-20 · Aux 1120KV8-B-21 · Aux 1221KV8-B-22 · Aux 1322KV8-B-23 · Aux 1423KV8-B-24 · Aux 1524KV8-B-25 · Aux 1625KV8-B-26 · Ignition 126KV8-B-27 · Ignition 227KV8-B-28 · Ignition 328KV8-B-29 · Ignition 429KV8-B-30 · Ignition 530KV8-B-31 · Ignition 631KV8-B-32 · Ignition 732KV8-B-33 · Ignition 833KV8-B-34 · ECU ground34
CavityFunctionSignalWireColourGauge (mm²)DestinationTerminalSealPlug
1Injection 1—W24—0.5OEM-4-U———
2Injection 2—W25—0.5OEM-4-V———
3Injection 3—W26—0.5OEM-4-W———
4Injection 4—W27—0.5OEM-4-X———
5Injection 5————————
6Injection 6————————
7Injection 7————————
8Injection 8————————
9ECU ground—W10—0.85SP-GND-1———
10Aux 1—W37—0.5OEM-4-J———
11Aux 2—W38—0.5OEM-4-O———
12Aux 3—W39—0.5OEM-4-P———
13Aux 4—W40—0.5OEM-4-Q———
14Aux 5—W32—0.5OEM-1-B———
15Aux 6—W33—0.5OEM-1-G———
16Aux 7—W34—0.5OEM-1-U———
17Aux 8—W36—0.5OEM-1-E———
18Aux 9————————
19Aux 10————————
20Aux 11————————
21Aux 12————————
22Aux 13————————
23Aux 14————————
24Aux 15————————
25Aux 16————————
26Ignition 1—W22—0.5OEM-4-N———
27Ignition 2—W23—0.5OEM-4-R———
28Ignition 3————————
29Ignition 4————————
30Ignition 5————————
31Ignition 6————————
32Ignition 7————————
33Ignition 8————————
34ECU ground—W9—0.85SP-GND-1———

KV8-C

Mating face
KV8-C-1 · ECU ground1KV8-C-2 · Analog in 12KV8-C-3 · Analog in 23KV8-C-4 · Analog in 34KV8-C-5 · Analog in 45KV8-C-6 · Analog in 56KV8-C-7 · Analog in 67KV8-C-8 · Analog in 78KV8-C-9 · Analog in 89KV8-C-10 · Analog in 910KV8-C-11 · Analog in 1011KV8-C-12 · Analog in 1112KV8-C-13 · Analog in 1213KV8-C-14 · Analog in 1314KV8-C-15 · Analog in 1415KV8-C-16 · Analog in 1516KV8-C-17 · Analog sensor 0V reference17KV8-C-18 · Digital in 918KV8-C-19 · Digital in 1019KV8-C-20 · Digital in 1120KV8-C-21 · Digital in 1221KV8-C-22 · Digital in 1322KV8-C-23 · Digital in 1423KV8-C-24 · Analog in 1624KV8-C-25 · Analog sensor 0V reference25KV8-C-26 · ECU ground26KV8-C-27 · Digital in 127KV8-C-28 · Digital in 228KV8-C-29 · Digital in 329KV8-C-30 · Digital in 430KV8-C-31 · Digital in 531KV8-C-32 · Digital in 632KV8-C-33 · Digital in 733KV8-C-34 · Digital in 834
Wire side
KV8-C-1 · ECU ground1KV8-C-2 · Analog in 12KV8-C-3 · Analog in 23KV8-C-4 · Analog in 34KV8-C-5 · Analog in 45KV8-C-6 · Analog in 56KV8-C-7 · Analog in 67KV8-C-8 · Analog in 78KV8-C-9 · Analog in 89KV8-C-10 · Analog in 910KV8-C-11 · Analog in 1011KV8-C-12 · Analog in 1112KV8-C-13 · Analog in 1213KV8-C-14 · Analog in 1314KV8-C-15 · Analog in 1415KV8-C-16 · Analog in 1516KV8-C-17 · Analog sensor 0V reference17KV8-C-18 · Digital in 918KV8-C-19 · Digital in 1019KV8-C-20 · Digital in 1120KV8-C-21 · Digital in 1221KV8-C-22 · Digital in 1322KV8-C-23 · Digital in 1423KV8-C-24 · Analog in 1624KV8-C-25 · Analog sensor 0V reference25KV8-C-26 · ECU ground26KV8-C-27 · Digital in 127KV8-C-28 · Digital in 228KV8-C-29 · Digital in 329KV8-C-30 · Digital in 430KV8-C-31 · Digital in 531KV8-C-32 · Digital in 632KV8-C-33 · Digital in 733KV8-C-34 · Digital in 834
CavityFunctionSignalWireColourGauge (mm²)DestinationTerminalSealPlug
1ECU ground—W11—0.85SP-GND-1———
2Analog in 1—W28—0.5OEM-3-B———
3Analog in 2—W29—0.5OEM-3-F———
4Analog in 3—W30—0.5OEM-3-G———
5Analog in 4—W42—0.5OEM-3-H———
6Analog in 5—W43—0.5OEM-3-N———
7Analog in 6—W44—0.5OEM-3-C———
8Analog in 7—W45—0.5OEM-3-D———
9Analog in 8—W46—0.5OEM-3-K———
10Analog in 9—W47—0.5OEM-3-J———
11Analog in 10————————
12Analog in 11————————
13Analog in 12————————
14Analog in 13————————
15Analog in 14————————
16Analog in 15————————
17Analog sensor 0V reference—W15—0.5SP-0V-1———
18Digital in 9————————
19Digital in 10————————
20Digital in 11————————
21Digital in 12————————
22Digital in 13————————
23Digital in 14————————
24Analog in 16————————
25Analog sensor 0V reference—W16—0.5SP-0V-1———
26ECU ground—W12—0.85SP-GND-1———
27Digital in 1—W48—0.5OEM-1-M———
28Digital in 2—W49—0.5OEM-1-C———
29Digital in 3—W50—0.5OEM-1-K———
30Digital in 4—W51—0.5OEM-1-L———
31Digital in 5—W52—0.5OEM-1-Q———
32Digital in 6—W53—0.5OEM-3-L———
33Digital in 7—W54—0.5OEM-3-P———
34Digital in 8————————

KV8-D

Mating face
KV8-D-1 · ECU 14V supply1KV8-D-2 · Aux 13–16 14V supply2KV8-D-3 · Sensor supply 8V3KV8-D-4 · Crank index sensor +4KV8-D-5 · Crank index sensor −5KV8-D-6 · Sync sensor +6KV8-D-7 · Sync sensor −7KV8-D-8 · CAN 1 H8KV8-D-9 · EFI relay output (low side, 200 mA)9KV8-D-10 · CAN 2 H10KV8-D-11 · Knock 1 +11KV8-D-12 · Knock 1 −12KV8-D-13 · Shield (crank/cam/knock)13KV8-D-14 · CAN 1 L14KV8-D-15 · Ignition switch input15KV8-D-16 · CAN 2 L16KV8-D-17 · Knock 2 +17KV8-D-18 · Knock 2 −18KV8-D-19 · Analog output 0–5V19KV8-D-20 · Aux 9–12 14V supply20KV8-D-21 · Sensor supply Vref1 5.0V21KV8-D-22 · Sensor supply Vref2 5.0V22KV8-D-23 · Ethernet Tx+23KV8-D-24 · Ethernet Tx−24KV8-D-25 · Ethernet Rx+25KV8-D-26 · Ethernet Rx−26
Wire side
KV8-D-1 · ECU 14V supply1KV8-D-2 · Aux 13–16 14V supply2KV8-D-3 · Sensor supply 8V3KV8-D-4 · Crank index sensor +4KV8-D-5 · Crank index sensor −5KV8-D-6 · Sync sensor +6KV8-D-7 · Sync sensor −7KV8-D-8 · CAN 1 H8KV8-D-9 · EFI relay output (low side, 200 mA)9KV8-D-10 · CAN 2 H10KV8-D-11 · Knock 1 +11KV8-D-12 · Knock 1 −12KV8-D-13 · Shield (crank/cam/knock)13KV8-D-14 · CAN 1 L14KV8-D-15 · Ignition switch input15KV8-D-16 · CAN 2 L16KV8-D-17 · Knock 2 +17KV8-D-18 · Knock 2 −18KV8-D-19 · Analog output 0–5V19KV8-D-20 · Aux 9–12 14V supply20KV8-D-21 · Sensor supply Vref1 5.0V21KV8-D-22 · Sensor supply Vref2 5.0V22KV8-D-23 · Ethernet Tx+23KV8-D-24 · Ethernet Tx−24KV8-D-25 · Ethernet Rx+25KV8-D-26 · Ethernet Rx−26
CavityFunctionSignalWireColourGauge (mm²)DestinationTerminalSealPlug
1ECU 14V supply—W2—0.85SP-14V-1———
2Aux 13–16 14V supply—W3—0.85SP-14V-1———
3Sensor supply 8V————————
4Crank index sensor +—W18—0.5OEM-4-E———
5Crank index sensor −—W19—0.5SP-0V-1———
6Sync sensor +—W20—0.5OEM-4-G———
7Sync sensor −—W21—0.5SP-0V-1———
8CAN 1 H————————
9EFI relay output (low side, 200 mA)—W31—0.5OEM-1-A———
10CAN 2 H————————
11Knock 1 +————————
12Knock 1 −————————
13Shield (crank/cam/knock)————————
14CAN 1 L————————
15Ignition switch input————————
16CAN 2 L————————
17Knock 2 +————————
18Knock 2 −————————
19Analog output 0–5V————————
20Aux 9–12 14V supply—W4—0.85SP-14V-1———
21Sensor supply Vref1 5.0V—W17—0.5OEM-3-I———
22Sensor supply Vref2 5.0V————————
23Ethernet Tx+————————
24Ethernet Tx−————————
25Ethernet Rx+————————
26Ethernet Rx−————————

OEM-1

CavityFunctionSignalWireColourGauge (mm²)DestinationTerminalSealPlug
ACooling fan relay (low-side)—W31—0.5KV8-D-9———
BA/C condenser fan relay—W32—0.5KV8-B-14———
CStarter input (12V while cranking)—W49—0.5KV8-C-28———
ECheck engine light (MIL)—W36—0.5KV8-B-17———
GA/C clutch relay—W33—0.5KV8-B-15———
KA/C pressure switch (A/C request)—W50—0.5KV8-C-29———
LClutch switch—W51—0.5KV8-C-30———
MVehicle speed sensor (VSS)—W48—0.5KV8-C-27———
QBrake switch—W52—0.5KV8-C-31———
UFuel pump relay (low-side)—W34—0.5KV8-B-16———

OEM-3

CavityFunctionSignalWireColourGauge (mm²)DestinationTerminalSealPlug
BMAF sensor input—W28—0.5KV8-C-2———
CFront O2 sensor input—W44—0.5KV8-C-7———
DRear O2 sensor input—W45—0.5KV8-C-8———
FThrottle position (TPS)—W29—0.5KV8-C-3———
GEngine coolant temp (CLT)—W30—0.5KV8-C-4———
HEGR boost sensor—W42—0.5KV8-C-5———
I+5V sensor reference—W17—0.5KV8-D-21———
JEGR valve position sensor—W47—0.5KV8-C-10———
KIntake air temp (IAT)—W46—0.5KV8-C-9———
LIdle switch (closed throttle)—W53—0.5KV8-C-32———
MFront O2 heater control—W35—0.5KV8-A-10———
NEGR boost sensor (2nd channel)—W43—0.5KV8-C-6———
OSensor ground—W13—0.5SP-0V-1———
PPower steering pressure switch—W54—0.5KV8-C-33———

OEM-4

CavityFunctionSignalWireColourGauge (mm²)DestinationTerminalSealPlug
AChassis ground—W5—0.85SP-GND-1———
BECU power +12V (main relay)—W1—0.85SP-14V-1———
CChassis ground—W6—0.85SP-GND-1———
DChassis ground—W7—0.85SP-GND-1———
ECrank position (CKP) sensor—W18—0.5KV8-D-4———
FCAS SGT (cam trigger)————————
GCAS SGC (cam sync)—W20—0.5KV8-D-6———
HCrank pickup timing ground (CKP gnd)—W14—0.5SP-0V-1———
IPermanent +12V (battery)————————
JPRC solenoid (FPR control)—W37—0.5KV8-B-10———
KChassis ground—W8—0.85SP-GND-1———
LTachometer output————————
NIgnition coil trigger (cyl 1&4)—W22—0.5KV8-B-26———
OEGR vent solenoid—W38—0.5KV8-B-11———
PEGR vacuum solenoid—W39—0.5KV8-B-12———
QIdle air control (IAC) valve—W40—0.5KV8-B-13———
RIgnition coil trigger (cyl 2&3)—W23—0.5KV8-B-27———
TEVAP purge solenoid—W41—0.5KV8-A-11———
UInjector 1 (cyl 1)—W24—0.5KV8-B-1———
VInjector 2 (cyl 2)—W25—0.5KV8-B-2———
WInjector 3 (cyl 3)—W26—0.5KV8-B-3———
XInjector 4 (cyl 4)—W27—0.5KV8-B-4———

SP-0V

CavityFunctionSignalWireColourGauge (mm²)DestinationTerminalSealPlug
1——W13—0.5OEM-3-O———
1——W14—0.5OEM-4-H———
1——W15—0.5KV8-C-17———
1——W16—0.5KV8-C-25———
1——W19—0.5KV8-D-5———
1——W21—0.5KV8-D-7———

SP-14V

CavityFunctionSignalWireColourGauge (mm²)DestinationTerminalSealPlug
1——W1—0.85OEM-4-B———
1——W2—0.85KV8-D-1———
1——W3—0.85KV8-D-2———
1——W4—0.85KV8-D-20———

SP-GND

CavityFunctionSignalWireColourGauge (mm²)DestinationTerminalSealPlug
1——W5—0.85OEM-4-A———
1——W6—0.85OEM-4-C———
1——W7—0.85OEM-4-D———
1——W8—0.85OEM-4-K———
1——W9—0.85KV8-B-34———
1——W10—0.85KV8-B-9———
1——W11—0.85KV8-C-1———
1——W12—0.85KV8-C-26———

Pin map

OEM pointOEM functionOEM familyTarget pointTarget functionTarget familyWire colourEvidence
OEM-1-ACooling fan relay (low-side)low_side_outKV8-D-9EFI relay output (low side, 200 mA)low_side_outcorroborated
OEM-1-BA/C condenser fan relaylow_side_outKV8-B-14Aux 5low_side_outcorroborated
OEM-1-CStarter input (12V while cranking)digital_inKV8-C-28Digital in 2digital_incorroborated
OEM-1-ECheck engine light (MIL)low_side_outKV8-B-17Aux 8low_side_outcorroborated
OEM-1-GA/C clutch relaylow_side_outKV8-B-15Aux 6low_side_outcorroborated
OEM-1-KA/C pressure switch (A/C request)digital_inKV8-C-29Digital in 3digital_incorroborated
OEM-1-LClutch switchdigital_inKV8-C-30Digital in 4digital_incorroborated
OEM-1-MVehicle speed sensor (VSS)digital_inKV8-C-27Digital in 1digital_incorroborated
OEM-1-QBrake switchdigital_inKV8-C-31Digital in 5digital_incorroborated
OEM-1-UFuel pump relay (low-side)low_side_outKV8-B-16Aux 7low_side_outcorroborated
OEM-3-BMAF sensor inputanalog_inKV8-C-2Analog in 1analog_incorroborated
OEM-3-CFront O2 sensor inputlambda_nb_inKV8-C-7Analog in 6analog_incorroborated
OEM-3-DRear O2 sensor inputlambda_nb_inKV8-C-8Analog in 7analog_incorroborated
OEM-3-FThrottle position (TPS)analog_inKV8-C-3Analog in 2analog_incorroborated
OEM-3-GEngine coolant temp (CLT)temp_inKV8-C-4Analog in 3analog_incorroborated
OEM-3-HEGR boost sensoranalog_inKV8-C-5Analog in 4analog_incorroborated
OEM-3-I+5V sensor referencevrefKV8-D-21Sensor supply Vref1 5.0Vvrefcorroborated
OEM-3-JEGR valve position sensoranalog_inKV8-C-10Analog in 9analog_incorroborated
OEM-3-KIntake air temp (IAT)temp_inKV8-C-9Analog in 8analog_incorroborated
OEM-3-LIdle switch (closed throttle)digital_inKV8-C-32Digital in 6digital_incorroborated
OEM-3-MFront O2 heater controllow_side_outKV8-A-10Lambda 1 heater −low_side_outcorroborated
OEM-3-NEGR boost sensor (2nd channel)analog_inKV8-C-6Analog in 5analog_incorroborated
OEM-3-OSensor groundsensor_groundKV8-C-17 + KV8-C-25 + KV8-D-5 + KV8-D-7Analog sensor 0V reference + Analog sensor 0V reference + Crank index sensor − + Sync sensor −sensor_ground + trigger_incorroborated
OEM-3-PPower steering pressure switchdigital_inKV8-C-33Digital in 7digital_incorroborated
OEM-4-AChassis groundgroundKV8-B-34 + KV8-B-9 + KV8-C-1 + KV8-C-26ECU ground + ECU ground + ECU ground + ECU groundgroundcorroborated
OEM-4-BECU power +12V (main relay)power_inKV8-D-1 + KV8-D-2 + KV8-D-20ECU 14V supply + Aux 13–16 14V supply + Aux 9–12 14V supplypower_incorroborated
OEM-4-CChassis groundgroundKV8-B-34 + KV8-B-9 + KV8-C-1 + KV8-C-26ECU ground + ECU ground + ECU ground + ECU groundgroundcorroborated
OEM-4-DChassis groundgroundKV8-B-34 + KV8-B-9 + KV8-C-1 + KV8-C-26ECU ground + ECU ground + ECU ground + ECU groundgroundcorroborated
OEM-4-ECrank position (CKP) sensortrigger_inKV8-D-4Crank index sensor +trigger_incorroborated
OEM-4-FCAS SGT (cam trigger)trigger_in———corroborated
OEM-4-GCAS SGC (cam sync)trigger_inKV8-D-6Sync sensor +trigger_incorroborated
OEM-4-HCrank pickup timing ground (CKP gnd)sensor_groundKV8-C-17 + KV8-C-25 + KV8-D-5 + KV8-D-7Analog sensor 0V reference + Analog sensor 0V reference + Crank index sensor − + Sync sensor −sensor_ground + trigger_incorroborated
OEM-4-IPermanent +12V (battery)power_in———corroborated
OEM-4-JPRC solenoid (FPR control)low_side_outKV8-B-10Aux 1low_side_outcorroborated
OEM-4-KChassis groundgroundKV8-B-34 + KV8-B-9 + KV8-C-1 + KV8-C-26ECU ground + ECU ground + ECU ground + ECU groundgroundcorroborated
OEM-4-LTachometer outputtacho_out———corroborated
OEM-4-NIgnition coil trigger (cyl 1&4)ignition_outKV8-B-26Ignition 1ignition_outcorroborated
OEM-4-OEGR vent solenoidlow_side_outKV8-B-11Aux 2low_side_outcorroborated
OEM-4-PEGR vacuum solenoidlow_side_outKV8-B-12Aux 3low_side_outcorroborated
OEM-4-QIdle air control (IAC) valvelow_side_outKV8-B-13Aux 4low_side_outcorroborated
OEM-4-RIgnition coil trigger (cyl 2&3)ignition_outKV8-B-27Ignition 2ignition_outcorroborated
OEM-4-TEVAP purge solenoidlow_side_outKV8-A-11Lambda 2 heater −low_side_outcorroborated
OEM-4-UInjector 1 (cyl 1)injector_outKV8-B-1Injection 1injector_outcorroborated
OEM-4-VInjector 2 (cyl 2)injector_outKV8-B-2Injection 2injector_outcorroborated
OEM-4-WInjector 3 (cyl 3)injector_outKV8-B-3Injection 3injector_outcorroborated
OEM-4-XInjector 4 (cyl 4)injector_outKV8-B-4Injection 4injector_outcorroborated

Cut list

WireFromToGauge (mm²)ColourLengthSignalIdent
W1OEM-4-BSP-14V-10.85no routeECU power +12V (main relay)—
W2SP-14V-1KV8-D-10.85no routeECU 14V supply—
W3SP-14V-1KV8-D-20.85no routeAux 13–16 14V supply—
W4SP-14V-1KV8-D-200.85no routeAux 9–12 14V supply—
W5OEM-4-ASP-GND-10.85no routeChassis ground—
W6OEM-4-CSP-GND-10.85no routeChassis ground—
W7OEM-4-DSP-GND-10.85no routeChassis ground—
W8OEM-4-KSP-GND-10.85no routeChassis ground—
W9SP-GND-1KV8-B-340.85no routeECU ground—
W10SP-GND-1KV8-B-90.85no routeECU ground—
W11SP-GND-1KV8-C-10.85no routeECU ground—
W12SP-GND-1KV8-C-260.85no routeECU ground—
W13OEM-3-OSP-0V-10.5no routeSensor ground—
W14OEM-4-HSP-0V-10.5no routeCrank pickup timing ground (CKP gnd)—
W15SP-0V-1KV8-C-170.5no routeAnalog sensor 0V reference—
W16SP-0V-1KV8-C-250.5no routeAnalog sensor 0V reference—
W17OEM-3-IKV8-D-210.5no route+5V sensor reference—
W18OEM-4-EKV8-D-40.5no routeCrank position (CKP) sensor—
W19SP-0V-1KV8-D-50.5no routeCrank index sensor −—
W20OEM-4-GKV8-D-60.5no routeCAS SGC (cam sync)—
W21SP-0V-1KV8-D-70.5no routeSync sensor −—
W22OEM-4-NKV8-B-260.5no routeIgnition coil trigger (cyl 1&4)—
W23OEM-4-RKV8-B-270.5no routeIgnition coil trigger (cyl 2&3)—
W24OEM-4-UKV8-B-10.5no routeInjector 1 (cyl 1)—
W25OEM-4-VKV8-B-20.5no routeInjector 2 (cyl 2)—
W26OEM-4-WKV8-B-30.5no routeInjector 3 (cyl 3)—
W27OEM-4-XKV8-B-40.5no routeInjector 4 (cyl 4)—
W28OEM-3-BKV8-C-20.5no routeMAF sensor input—
W29OEM-3-FKV8-C-30.5no routeThrottle position (TPS)—
W30OEM-3-GKV8-C-40.5no routeEngine coolant temp (CLT)—
W31OEM-1-AKV8-D-90.5no routeCooling fan relay (low-side)—
W32OEM-1-BKV8-B-140.5no routeA/C condenser fan relay—
W33OEM-1-GKV8-B-150.5no routeA/C clutch relay—
W34OEM-1-UKV8-B-160.5no routeFuel pump relay (low-side)—
W35OEM-3-MKV8-A-100.5no routeFront O2 heater control—
W36OEM-1-EKV8-B-170.5no routeCheck engine light (MIL)—
W37OEM-4-JKV8-B-100.5no routePRC solenoid (FPR control)—
W38OEM-4-OKV8-B-110.5no routeEGR vent solenoid—
W39OEM-4-PKV8-B-120.5no routeEGR vacuum solenoid—
W40OEM-4-QKV8-B-130.5no routeIdle air control (IAC) valve—
W41OEM-4-TKV8-A-110.5no routeEVAP purge solenoid—
W42OEM-3-HKV8-C-50.5no routeEGR boost sensor—
W43OEM-3-NKV8-C-60.5no routeEGR boost sensor (2nd channel)—
W44OEM-3-CKV8-C-70.5no routeFront O2 sensor input—
W45OEM-3-DKV8-C-80.5no routeRear O2 sensor input—
W46OEM-3-KKV8-C-90.5no routeIntake air temp (IAT)—
W47OEM-3-JKV8-C-100.5no routeEGR valve position sensor—
W48OEM-1-MKV8-C-270.5no routeVehicle speed sensor (VSS)—
W49OEM-1-CKV8-C-280.5no routeStarter input (12V while cranking)—
W50OEM-1-KKV8-C-290.5no routeA/C pressure switch (A/C request)—
W51OEM-1-LKV8-C-300.5no routeClutch switch—
W52OEM-1-QKV8-C-310.5no routeBrake switch—
W53OEM-3-LKV8-C-320.5no routeIdle switch (closed throttle)—
W54OEM-3-PKV8-C-330.5no routePower steering pressure switch—

Bill of materials

CategoryPart numberManufacturerDescriptionQtyUnit
connector3-1437290-7TESuperseal 1.0 26-way plug1.000ea
connector3-1437290-8TESuperseal 1.0 26-way plug, Key 21.000ea
connector4-1437290-0TESuperseal 1.0 34-way plug, Key 11.000ea
connector4-1437290-1TESuperseal 1.0 34-way plug, Key 21.000ea
terminal3-1447221-4TESuperseal 1.0 socket terminal, 20 AWG (0.5 sq mm)47.000ea

ECU setup sheet

RoleEngine refEngine signalSensorECU pointECU functionECU classSetup flag
No configured channels.

Findings

Open (6)

SeverityCodeSubjectMessage
errorREQUIRED_UNMAPPEDOEM-4-FRequired OEM function "CAS SGT (cam trigger)" (trigger_in) is not connected to the new ECU.
warnDATASET_GAPKV8 A14 of 26 cavities on KV8 A have no pin data (1,2,3,4,5,6,7,8,9,12,13,14,15,19). Anything there is invisible to these checks.
infoNET_FAMILYKV8-C-17 ↔ KV8-D-7KV8-C-17 "Analog sensor 0V reference" [sensor_ground] is wired to KV8-D-7 "Sync sensor −" [trigger_in]. Trigger return tied to sensor/trigger ground: correct for single-ended trigger inputs.
infoNET_FAMILYOEM-3-G ↔ KV8-C-4OEM-3-G "Engine coolant temp (CLT)" [temp_in] is wired to KV8-C-4 "Analog in 3" [analog_in]. Thermistor on a plain analog input needs a pull-up; check the channel can enable one.
infoNET_FAMILYOEM-3-K ↔ KV8-C-9OEM-3-K "Intake air temp (IAT)" [temp_in] is wired to KV8-C-9 "Analog in 8" [analog_in]. Thermistor on a plain analog input needs a pull-up; check the channel can enable one.
infoUNMAPPEDOEM1 optional OEM pins are not mapped: OEM-4-L Tachometer output

Accepted (1)

CodeSubjectReasonBy
REQUIRED_UNMAPPEDOEM-4-IBattery-constant (memory) feed of the stock ECU: the new ECU has no such input, so it is not needed.mapping-proposal

Notes

Auto-mapped by auto_map() from the library pin data on 2026-10-11. Review every wire against both manuals before building. Open items: - OEM-4 F: CAS SGT (cam trigger): no free cam_hall/cam_vr/frequency_in input on Emtron KV8 Not wired: - OEM-4 I: Permanent +12V (battery): Emtron KV8 has no battery-constant input; not needed - OEM-4 L: Tachometer output: no free tacho/frequency_out/low_side/ls_hs on Emtron KV8 - KV8-D 15: Ignition switch input: not fed (the stock ECU has no ignition-sense pin); feed it from a switched-ignition source

Sources

ReliabilityKindTitleURLArchiveCapturedSHA-256
4vendor_docAEM EMS 30-1720 Plug-and-Play adapter manual (1996-97 Miata)https://static.summitracing.com/global/images/instructions/avm-30-1720.pdf———
3community_copyMellens.net: 1996 Mazda Miata wiring diagrams (FSM-derived)http://www.mellens.net/mazda/mazda_miata_extra_manual/1996_wiring.pdf———
2user_datasetSubaru ECU Matcher dataset (hiubin), vehicleId=1————