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MX-5 Miata NB2 2001-05 (BP-Z3, VVT) → Haltech Elite 2500 HT-151300 (auto)

MX-5 Miata NB2 2001-05 (BP-Z3, VVT) — Haltech — Elite 2500
Drawn by Michael Gnankou · Rev 0 · proposal · 2026-10-04

Revisions

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Schematic

ELITE2500-AELITE2500-BOEM-2OEM-3OEM-4SP-0VSP-14VSP-GND

Connectors

ELITE2500-A

CavityFunctionSignalWireColourGauge (mm²)DestinationTerminalSealPlug
1DPO 2—W28—0.5OEM-2-K———
10Battery ground—W8—0.85SP-GND-1———
11Battery ground—W9—0.85SP-GND-1———
12+8V DC————————
1312V ignition input————————
14AVI 10 (TPS)—W55—0.5OEM-4-I———
15AVI 9 (MAP)—W54—0.5OEM-4-H———
16AVI 2—W43—0.5OEM-4-V———
17AVI 3—W44—0.5OEM-4-AA———
18DPO 1—W27—0.5OEM-2-C———
19INJ 1—W22—0.5OEM-2-A———
2AVI 4—W45—0.5OEM-4-W———
20INJ 2—W23—0.5OEM-2-D———
21INJ 3—W24—0.5OEM-2-G———
22INJ 4—W25—0.5OEM-2-J———
23DPO 3—W30—0.5OEM-3-H———
24DPO 5 (fuel pump trigger)—W29—0.5OEM-2-M———
25DPO 6 (ECR OUT)—W26—0.5OEM-2-B———
26ECU injector power input—W3—0.85SP-14V-1———
27INJ 5—W36—0.5OEM-2-H———
28INJ 6—W37—0.5OEM-2-I———
29INJ 7—W38—0.5OEM-2-N———
3IGN 1—W20—0.5OEM-3-F———
30INJ 8—W39—0.5OEM-2-R———
31Stepper 1 P1 / DPO—W32—0.5OEM-3-P———
32Stepper 1 P2 / DPO—W33—0.5OEM-2-Q———
33Stepper 1 P3 / DPO—W34—0.5OEM-2-E———
34Stepper 1 P4 / DPO—W35—0.5OEM-2-F———
4IGN 2—W21—0.5OEM-3-I———
5IGN 3————————
6IGN 4————————
7IGN 5————————
8IGN 6————————
9+5V DC—W14—0.5OEM-4-L———

ELITE2500-B

CavityFunctionSignalWireColourGauge (mm²)DestinationTerminalSealPlug
1Crank (Trigger) (+)—W15—0.5OEM-3-Y———
10SPI 3—W51—0.5OEM-4-B———
11+13.8V ECU supply—W4—0.85SP-14V-1———
12AVI 6 (O2 Input 1)—W48—0.5OEM-4-AD———
13AVI 1 (O2 Input 2)—W42—0.5OEM-4-X———
14Signal ground—W11—0.5SP-0V-1———
15Signal ground—W12—0.5SP-0V-1———
16Signal ground—W13—0.5SP-0V-1———
17IGN 7————————
18IGN 8————————
19DPO 4—W31—0.5OEM-3-J———
2Cam (Home) (+)—W17—0.5OEM-3-V———
20AVI 5—W47—0.5OEM-4-N———
21KNOCK 1—W19—0.5OEM-4-M———
22KNOCK 2————————
23CAN H————————
24CAN L————————
25DBW 1 / DPO—W40—0.5OEM-3-D———
26DBW 2 / DPO—W41—0.5OEM-3-E———
3AVI 7 (Air Temp)—W53—0.5OEM-4-F———
4AVI 8 (Coolant Temp)—W46—0.5OEM-4-P———
5Crank (Trigger) (−)—W16—0.5SP-0V-1———
6Cam (Home) (−)—W18—0.5SP-0V-1———
7SPI 4—W52—0.5OEM-4-C———
8SPI 1—W49—0.5OEM-3-T———
9SPI 2—W50—0.5OEM-3-S———

OEM-2

CavityFunctionSignalWireColourGauge (mm²)DestinationTerminalSealPlug
AInjector 1—W22—0.5ELITE2500-A-19———
BCooling fan relay—W26—0.5ELITE2500-A-25———
CCondenser fan relay—W27—0.5ELITE2500-A-18———
DInjector 2—W23—0.5ELITE2500-A-20———
EEGR valve—W34—0.5ELITE2500-A-33———
FEGR valve—W35—0.5ELITE2500-A-34———
GInjector 3—W24—0.5ELITE2500-A-21———
HEGR valve—W36—0.5ELITE2500-A-27———
IEGR valve—W37—0.5ELITE2500-A-28———
JInjector 4—W25—0.5ELITE2500-A-22———
KA/C clutch relay—W28—0.5ELITE2500-A-1———
MFuel pump relay—W29—0.5ELITE2500-A-24———
NVTCS solenoid (intake butterflies)—W38—0.5ELITE2500-A-29———
PISC valve +14V feed—W1—0.85SP-14V-1———
QISC valve low side—W33—0.5ELITE2500-A-32———
RMalfunction indicator lamp (MIL)—W39—0.5ELITE2500-A-30———

OEM-3

CavityFunctionSignalWireColourGauge (mm²)DestinationTerminalSealPlug
APower ground—W5—0.85SP-GND-1———
BPower ground—W6—0.85SP-GND-1———
DEGR boost solenoid—W40—0.5ELITE2500-B-25———
ECharcoal canister purge—W41—0.5ELITE2500-B-26———
FIgnition 1 (coils 1+4, wasted spark)—W20—0.5ELITE2500-A-3———
HMain relay—W30—0.5ELITE2500-A-23———
IIgnition 2 (coils 2+3, wasted spark)—W21—0.5ELITE2500-A-4———
JFront O2 heater—W31—0.5ELITE2500-B-19———
MAlternator control————————
OTachometer output————————
PRear O2 heater—W32—0.5ELITE2500-A-31———
SImmobiliser—W50—0.5ELITE2500-B-9———
TVehicle speed—W49—0.5ELITE2500-B-8———
UCharge lamp————————
VCam position (CMP)—W17—0.5ELITE2500-B-2———
YCrank position (CKP)—W15—0.5ELITE2500-B-1———

OEM-4

CavityFunctionSignalWireColourGauge (mm²)DestinationTerminalSealPlug
APower ground—W7—0.85SP-GND-1———
AARear O2 signal—W44—0.5ELITE2500-A-17———
ADFuel level—W48—0.5ELITE2500-B-12———
AFECU power +14V (main relay)—W2—0.85SP-14V-1———
AGConstant +12V————————
BBrake switch—W51—0.5ELITE2500-B-10———
CPower steering pressure switch—W52—0.5ELITE2500-B-7———
DVVT oil-control solenoid————————
FA/C request—W53—0.5ELITE2500-B-3———
HNeutral switch—W54—0.5ELITE2500-A-15———
IClutch switch—W55—0.5ELITE2500-A-14———
JVTCS vacuum switch————————
L+5V sensor supply—W14—0.5ELITE2500-A-9———
MKnock sensor—W19—0.5ELITE2500-B-21———
NIntake air temperature (IAT)—W47—0.5ELITE2500-B-20———
OSignal ground—W10—0.5SP-0V-1———
PCoolant temperature (ECT)—W46—0.5ELITE2500-B-4———
VThrottle position (TPS)—W43—0.5ELITE2500-A-16———
WFront O2 signal—W45—0.5ELITE2500-A-2———
XMass air flow (MAF)—W42—0.5ELITE2500-B-13———

SP-0V

CavityFunctionSignalWireColourGauge (mm²)DestinationTerminalSealPlug
1——W10—0.5OEM-4-O———
1——W11—0.5ELITE2500-B-14———
1——W12—0.5ELITE2500-B-15———
1——W13—0.5ELITE2500-B-16———
1——W16—0.5ELITE2500-B-5———
1——W18—0.5ELITE2500-B-6———

SP-14V

CavityFunctionSignalWireColourGauge (mm²)DestinationTerminalSealPlug
1——W1—0.85OEM-2-P———
1——W2—0.85OEM-4-AF———
1——W3—0.85ELITE2500-A-26———
1——W4—0.85ELITE2500-B-11———

SP-GND

CavityFunctionSignalWireColourGauge (mm²)DestinationTerminalSealPlug
1——W5—0.85OEM-3-A———
1——W6—0.85OEM-3-B———
1——W7—0.85OEM-4-A———
1——W8—0.85ELITE2500-A-10———
1——W9—0.85ELITE2500-A-11———

Pin map

OEM pointOEM functionOEM familyTarget pointTarget functionTarget familyWire colourEvidence
OEM-2-AInjector 1injector_outELITE2500-A-19INJ 1injector_outsingle_source
OEM-2-BCooling fan relaylow_side_outELITE2500-A-25DPO 6 (ECR OUT)low_side_outsingle_source
OEM-2-CCondenser fan relaylow_side_outELITE2500-A-18DPO 1low_side_outsingle_source
OEM-2-DInjector 2injector_outELITE2500-A-20INJ 2injector_outsingle_source
OEM-2-EEGR valvelow_side_outELITE2500-A-33Stepper 1 P3 / DPOswitch_outsingle_source
OEM-2-FEGR valvelow_side_outELITE2500-A-34Stepper 1 P4 / DPOswitch_outsingle_source
OEM-2-GInjector 3injector_outELITE2500-A-21INJ 3injector_outsingle_source
OEM-2-HEGR valvelow_side_outELITE2500-A-27INJ 5injector_outsingle_source
OEM-2-IEGR valvelow_side_outELITE2500-A-28INJ 6injector_outsingle_source
OEM-2-JInjector 4injector_outELITE2500-A-22INJ 4injector_outsingle_source
OEM-2-KA/C clutch relaylow_side_outELITE2500-A-1DPO 2low_side_outsingle_source
OEM-2-MFuel pump relaylow_side_outELITE2500-A-24DPO 5 (fuel pump trigger)low_side_outsingle_source
OEM-2-NVTCS solenoid (intake butterflies)low_side_outELITE2500-A-29INJ 7injector_outsingle_source
OEM-2-PISC valve +14V feedpower_inELITE2500-A-26 + ELITE2500-B-11ECU injector power input + +13.8V ECU supplypower_insingle_source
OEM-2-QISC valve low sidelow_side_outELITE2500-A-32Stepper 1 P2 / DPOswitch_outsingle_source
OEM-2-RMalfunction indicator lamp (MIL)low_side_outELITE2500-A-30INJ 8injector_outsingle_source
OEM-3-APower groundgroundELITE2500-A-10 + ELITE2500-A-11Battery ground + Battery groundgroundsingle_source
OEM-3-BPower groundgroundELITE2500-A-10 + ELITE2500-A-11Battery ground + Battery groundgroundsingle_source
OEM-3-DEGR boost solenoidlow_side_outELITE2500-B-25DBW 1 / DPOhbridge_outsingle_source
OEM-3-ECharcoal canister purgelow_side_outELITE2500-B-26DBW 2 / DPOhbridge_outsingle_source
OEM-3-FIgnition 1 (coils 1+4, wasted spark)ignition_outELITE2500-A-3IGN 1ignition_outsingle_source
OEM-3-HMain relaylow_side_outELITE2500-A-23DPO 3low_side_outsingle_source
OEM-3-IIgnition 2 (coils 2+3, wasted spark)ignition_outELITE2500-A-4IGN 2ignition_outsingle_source
OEM-3-JFront O2 heaterlow_side_outELITE2500-B-19DPO 4low_side_outsingle_source
OEM-3-MAlternator controllow_side_out———single_source
OEM-3-OTachometer outputtacho_out———single_source
OEM-3-PRear O2 heaterlow_side_outELITE2500-A-31Stepper 1 P1 / DPOswitch_outsingle_source
OEM-3-SImmobiliserdigital_inELITE2500-B-9SPI 2digital_insingle_source
OEM-3-TVehicle speeddigital_inELITE2500-B-8SPI 1digital_insingle_source
OEM-3-UCharge lamplow_side_out———single_source
OEM-3-VCam position (CMP)trigger_inELITE2500-B-2Cam (Home) (+)trigger_insingle_source
OEM-3-YCrank position (CKP)trigger_inELITE2500-B-1Crank (Trigger) (+)trigger_insingle_source
OEM-4-APower groundgroundELITE2500-A-10 + ELITE2500-A-11Battery ground + Battery groundgroundsingle_source
OEM-4-AARear O2 signallambda_nb_inELITE2500-A-17AVI 3analog_insingle_source
OEM-4-ADFuel levelanalog_inELITE2500-B-12AVI 6 (O2 Input 1)analog_insingle_source
OEM-4-AFECU power +14V (main relay)power_inELITE2500-A-26 + ELITE2500-B-11ECU injector power input + +13.8V ECU supplypower_insingle_source
OEM-4-AGConstant +12Vpower_in———single_source
OEM-4-BBrake switchdigital_inELITE2500-B-10SPI 3digital_insingle_source
OEM-4-CPower steering pressure switchdigital_inELITE2500-B-7SPI 4digital_insingle_source
OEM-4-DVVT oil-control solenoidlow_side_out———single_source
OEM-4-FA/C requestdigital_inELITE2500-B-3AVI 7 (Air Temp)analog_insingle_source
OEM-4-HNeutral switchdigital_inELITE2500-A-15AVI 9 (MAP)analog_insingle_source
OEM-4-IClutch switchdigital_inELITE2500-A-14AVI 10 (TPS)analog_insingle_source
OEM-4-JVTCS vacuum switchdigital_in———single_source
OEM-4-L+5V sensor supplyvrefELITE2500-A-9+5V DCvrefsingle_source
OEM-4-MKnock sensorknock_inELITE2500-B-21KNOCK 1knock_insingle_source
OEM-4-NIntake air temperature (IAT)temp_inELITE2500-B-20AVI 5analog_insingle_source
OEM-4-OSignal groundsensor_groundELITE2500-B-14 + ELITE2500-B-15 + ELITE2500-B-16 + ELITE2500-B-5 + ELITE2500-B-6Signal ground + Signal ground + Signal ground + Crank (Trigger) (−) + Cam (Home) (−)sensor_ground + trigger_insingle_source
OEM-4-PCoolant temperature (ECT)temp_inELITE2500-B-4AVI 8 (Coolant Temp)analog_insingle_source
OEM-4-VThrottle position (TPS)analog_inELITE2500-A-16AVI 2analog_insingle_source
OEM-4-WFront O2 signallambda_nb_inELITE2500-A-2AVI 4analog_insingle_source
OEM-4-XMass air flow (MAF)analog_inELITE2500-B-13AVI 1 (O2 Input 2)analog_insingle_source

Cut list

WireFromToGauge (mm²)ColourLengthSignalIdent
W1OEM-2-PSP-14V-10.85no routeISC valve +14V feed—
W2OEM-4-AFSP-14V-10.85no routeECU power +14V (main relay)—
W3SP-14V-1ELITE2500-A-260.85no routeECU injector power input—
W4SP-14V-1ELITE2500-B-110.85no route+13.8V ECU supply—
W5OEM-3-ASP-GND-10.85no routePower ground—
W6OEM-3-BSP-GND-10.85no routePower ground—
W7OEM-4-ASP-GND-10.85no routePower ground—
W8SP-GND-1ELITE2500-A-100.85no routeBattery ground—
W9SP-GND-1ELITE2500-A-110.85no routeBattery ground—
W10OEM-4-OSP-0V-10.5no routeSignal ground—
W11SP-0V-1ELITE2500-B-140.5no routeSignal ground—
W12SP-0V-1ELITE2500-B-150.5no routeSignal ground—
W13SP-0V-1ELITE2500-B-160.5no routeSignal ground—
W14OEM-4-LELITE2500-A-90.5no route+5V sensor supply—
W15OEM-3-YELITE2500-B-10.5no routeCrank position (CKP)—
W16SP-0V-1ELITE2500-B-50.5no routeCrank (Trigger) (−)—
W17OEM-3-VELITE2500-B-20.5no routeCam position (CMP)—
W18SP-0V-1ELITE2500-B-60.5no routeCam (Home) (−)—
W19OEM-4-MELITE2500-B-210.5no routeKnock sensor—
W20OEM-3-FELITE2500-A-30.5no routeIgnition 1 (coils 1+4, wasted spark)—
W21OEM-3-IELITE2500-A-40.5no routeIgnition 2 (coils 2+3, wasted spark)—
W22OEM-2-AELITE2500-A-190.5no routeInjector 1—
W23OEM-2-DELITE2500-A-200.5no routeInjector 2—
W24OEM-2-GELITE2500-A-210.5no routeInjector 3—
W25OEM-2-JELITE2500-A-220.5no routeInjector 4—
W26OEM-2-BELITE2500-A-250.5no routeCooling fan relay—
W27OEM-2-CELITE2500-A-180.5no routeCondenser fan relay—
W28OEM-2-KELITE2500-A-10.5no routeA/C clutch relay—
W29OEM-2-MELITE2500-A-240.5no routeFuel pump relay—
W30OEM-3-HELITE2500-A-230.5no routeMain relay—
W31OEM-3-JELITE2500-B-190.5no routeFront O2 heater—
W32OEM-3-PELITE2500-A-310.5no routeRear O2 heater—
W33OEM-2-QELITE2500-A-320.5no routeISC valve low side—
W34OEM-2-EELITE2500-A-330.5no routeEGR valve—
W35OEM-2-FELITE2500-A-340.5no routeEGR valve—
W36OEM-2-HELITE2500-A-270.5no routeEGR valve—
W37OEM-2-IELITE2500-A-280.5no routeEGR valve—
W38OEM-2-NELITE2500-A-290.5no routeVTCS solenoid (intake butterflies)—
W39OEM-2-RELITE2500-A-300.5no routeMalfunction indicator lamp (MIL)—
W40OEM-3-DELITE2500-B-250.5no routeEGR boost solenoid—
W41OEM-3-EELITE2500-B-260.5no routeCharcoal canister purge—
W42OEM-4-XELITE2500-B-130.5no routeMass air flow (MAF)—
W43OEM-4-VELITE2500-A-160.5no routeThrottle position (TPS)—
W44OEM-4-AAELITE2500-A-170.5no routeRear O2 signal—
W45OEM-4-WELITE2500-A-20.5no routeFront O2 signal—
W46OEM-4-PELITE2500-B-40.5no routeCoolant temperature (ECT)—
W47OEM-4-NELITE2500-B-200.5no routeIntake air temperature (IAT)—
W48OEM-4-ADELITE2500-B-120.5no routeFuel level—
W49OEM-3-TELITE2500-B-80.5no routeVehicle speed—
W50OEM-3-SELITE2500-B-90.5no routeImmobiliser—
W51OEM-4-BELITE2500-B-100.5no routeBrake switch—
W52OEM-4-CELITE2500-B-70.5no routePower steering pressure switch—
W53OEM-4-FELITE2500-B-30.5no routeA/C request—
W54OEM-4-HELITE2500-A-150.5no routeNeutral switch—
W55OEM-4-IELITE2500-A-140.5no routeClutch switch—

Bill of materials

CategoryPart numberManufacturerDescriptionQtyUnit

ECU setup sheet

RoleEngine refEngine signalSensorECU pointECU functionECU classSetup flag
No configured channels.

Findings

Open (17)

SeverityCodeSubjectMessage
warnNET_FAMILYOEM-3-D ↔ ELITE2500-B-25OEM-3-D "EGR boost solenoid" [low_side_out] is wired to ELITE2500-B-25 "DBW 1 / DPO" [hbridge_out]. A half-bridge can act as a low-side switch only if configured that way.
warnNET_FAMILYOEM-3-E ↔ ELITE2500-B-26OEM-3-E "Charcoal canister purge" [low_side_out] is wired to ELITE2500-B-26 "DBW 2 / DPO" [hbridge_out]. A half-bridge can act as a low-side switch only if configured that way.
warnNET_FAMILYOEM-4-F ↔ ELITE2500-B-3OEM-4-F "A/C request" [digital_in] is wired to ELITE2500-B-3 "AVI 7 (Air Temp)" [analog_in]. Analog and digital on one net. A switch on an analog input works with a pull-up and a threshold; an analog sensor on a digital input loses its value.
warnNET_FAMILYOEM-4-H ↔ ELITE2500-A-15OEM-4-H "Neutral switch" [digital_in] is wired to ELITE2500-A-15 "AVI 9 (MAP)" [analog_in]. Analog and digital on one net. A switch on an analog input works with a pull-up and a threshold; an analog sensor on a digital input loses its value.
warnNET_FAMILYOEM-4-I ↔ ELITE2500-A-14OEM-4-I "Clutch switch" [digital_in] is wired to ELITE2500-A-14 "AVI 10 (TPS)" [analog_in]. Analog and digital on one net. A switch on an analog input works with a pull-up and a threshold; an analog sensor on a digital input loses its value.
infoNET_FAMILYOEM-2-E ↔ ELITE2500-A-33OEM-2-E "EGR valve" [low_side_out] is wired to ELITE2500-A-33 "Stepper 1 P3 / DPO" [switch_out]. Configure this output as low side.
infoNET_FAMILYOEM-2-F ↔ ELITE2500-A-34OEM-2-F "EGR valve" [low_side_out] is wired to ELITE2500-A-34 "Stepper 1 P4 / DPO" [switch_out]. Configure this output as low side.
infoNET_FAMILYOEM-2-H ↔ ELITE2500-A-27OEM-2-H "EGR valve" [low_side_out] is wired to ELITE2500-A-27 "INJ 5" [injector_out]. Injector drivers can usually run general low-side loads; check current and PWM frequency.
infoNET_FAMILYOEM-2-I ↔ ELITE2500-A-28OEM-2-I "EGR valve" [low_side_out] is wired to ELITE2500-A-28 "INJ 6" [injector_out]. Injector drivers can usually run general low-side loads; check current and PWM frequency.
infoNET_FAMILYOEM-2-N ↔ ELITE2500-A-29OEM-2-N "VTCS solenoid (intake butterflies)" [low_side_out] is wired to ELITE2500-A-29 "INJ 7" [injector_out]. Injector drivers can usually run general low-side loads; check current and PWM frequency.
infoNET_FAMILYOEM-2-Q ↔ ELITE2500-A-32OEM-2-Q "ISC valve low side" [low_side_out] is wired to ELITE2500-A-32 "Stepper 1 P2 / DPO" [switch_out]. Configure this output as low side.
infoNET_FAMILYOEM-2-R ↔ ELITE2500-A-30OEM-2-R "Malfunction indicator lamp (MIL)" [low_side_out] is wired to ELITE2500-A-30 "INJ 8" [injector_out]. Injector drivers can usually run general low-side loads; check current and PWM frequency.
infoNET_FAMILYOEM-3-P ↔ ELITE2500-A-31OEM-3-P "Rear O2 heater" [low_side_out] is wired to ELITE2500-A-31 "Stepper 1 P1 / DPO" [switch_out]. Configure this output as low side.
infoNET_FAMILYOEM-4-N ↔ ELITE2500-B-20OEM-4-N "Intake air temperature (IAT)" [temp_in] is wired to ELITE2500-B-20 "AVI 5" [analog_in]. Thermistor on a plain analog input needs a pull-up; check the channel can enable one.
infoNET_FAMILYOEM-4-O ↔ ELITE2500-B-6OEM-4-O "Signal ground" [sensor_ground] is wired to ELITE2500-B-6 "Cam (Home) (−)" [trigger_in]. Trigger return tied to sensor/trigger ground: correct for single-ended trigger inputs.
infoNET_FAMILYOEM-4-P ↔ ELITE2500-B-4OEM-4-P "Coolant temperature (ECT)" [temp_in] is wired to ELITE2500-B-4 "AVI 8 (Coolant Temp)" [analog_in]. Thermistor on a plain analog input needs a pull-up; check the channel can enable one.
infoUNMAPPEDOEM5 optional OEM pins are not mapped: OEM-3-M Alternator control; OEM-3-O Tachometer output; OEM-3-U Charge lamp; OEM-4-D VVT oil-control solenoid; OEM-4-J VTCS vacuum switch

Accepted (1)

CodeSubjectReasonBy
REQUIRED_UNMAPPEDOEM-4-AGBattery-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 2026-10-04. Review every wire against both manuals before building. Not wired: - OEM-4 AG: Constant +12V: Haltech Elite 2500 has no battery-constant input; not needed - OEM-3 M: Alternator control: no free low_side/ls_hs/injector/hbridge on Haltech Elite 2500 - OEM-3 U: Charge lamp: no free low_side/ls_hs/injector/hbridge on Haltech Elite 2500 - OEM-4 D: VVT oil-control solenoid: no free low_side/ls_hs/injector/hbridge on Haltech Elite 2500 - OEM-3 O: Tachometer output: no free tacho/frequency_out/low_side/ls_hs on Haltech Elite 2500 - OEM-4 J: VTCS vacuum switch: no free switch_in/frequency_in/analog_0_5 on Haltech Elite 2500 - ELITE2500-A 13: 12V ignition input: not fed (the stock ECU has no ignition-sense pin); feed it from a switched-ignition source

Sources

ReliabilityKindTitleURL
4vendor_docHaltech Elite 2500 — 26-pin connector pinouthttps://support.haltech.com/portal/en/kb/articles/main-connector-26-pin-elite2500
4vendor_docHaltech Elite 2500 — 34-pin main connector pinouthttps://support.haltech.com/portal/en/kb/articles/main-connector-34-pin-elite2500
4datasheetHaltech Elite 2500 (HT-151300) spec sheethttps://joeblospeedshop.com/wp-content/uploads/2023/11/HT-151300_SPEC-SHEET-2500-ELITE.pdf
4vendor_docLink G4X MX5NB2X install manual (NB2 2001-05)https://linkecu.com/documentation/MX5XNB2.pdf