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VW Corrado VR6 12v (AAA) Motronic M2.9 OBD1 → AMP EFI MS3Pro Ultimate (auto)

VW Corrado VR6 12v (AAA) Motronic M2.9 OBD1 — AMP EFI — MS3Pro Ultimate
Drawn by Michael Gnankou · Rev 0 · proposal · 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.

Statusproposal · not yet verified: nobody has reported building and running this harness
Open errorsnone
Size of the job58 wires · 7 connectors · 0 part lines
ToolsCrimp and extraction tools for each terminal family (see Connectors) · wire strippers · multimeter · heat gun + heat-shrink
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-A-23SP-14V-10.85☐☐☐☐☐☐☐
W2SP-14V-1MS3PROULTIMA-A-350.85☐☐☐☐☐☐☐
W3OEM-A-54MS3PROULTIMA-C-230.85☐☐☐☐☐☐☐
W4OEM-A-1SP-GND-10.85☐☐☐☐☐☐☐
W5OEM-A-10SP-GND-10.85☐☐☐☐☐☐☐
W6OEM-A-55SP-GND-10.85☐☐☐☐☐☐☐
W7OEM-A-56SP-GND-10.85☐☐☐☐☐☐☐
W8OEM-A-7SP-GND-10.85☐☐☐☐☐☐☐
W9SP-GND-1MS3PROULTIMA-A-130.85☐☐☐☐☐☐☐
W10SP-GND-1MS3PROULTIMA-B-180.85☐☐☐☐☐☐☐
W11SP-GND-1MS3PROULTIMA-B-30.85☐☐☐☐☐☐☐
W12SP-GND-1MS3PROULTIMA-B-50.85☐☐☐☐☐☐☐
W13SP-GND-1MS3PROULTIMA-B-70.85☐☐☐☐☐☐☐
W14SP-GND-1MS3PROULTIMA-B-90.85☐☐☐☐☐☐☐
W15OEM-A-16SP-0V-10.5☐☐☐☐☐☐☐
W16OEM-A-33SP-0V-10.5☐☐☐☐☐☐☐
W17OEM-A-67SP-0V-10.5☐☐☐☐☐☐☐
W18SP-0V-1MS3PROULTIMA-A-160.5☐☐☐☐☐☐☐
W19SP-0V-1MS3PROULTIMA-A-180.5☐☐☐☐☐☐☐
W20SP-0V-1MS3PROULTIMA-C-170.5☐☐☐☐☐☐☐
W21SP-0V-1MS3PROULTIMA-C-180.5☐☐☐☐☐☐☐
W22SP-0V-1MS3PROULTIMA-C-190.5☐☐☐☐☐☐☐
W23SP-0V-1MS3PROULTIMA-C-200.5☐☐☐☐☐☐☐
W24SP-0V-1MS3PROULTIMA-C-210.5☐☐☐☐☐☐☐
W25OEM-A-41MS3PROULTIMA-A-80.5☐☐☐☐☐☐☐
W26OEM-A-68MS3PROULTIMA-A-60.5☐☐☐☐☐☐☐
W27SP-0V-1MS3PROULTIMA-A-150.5☐☐☐☐☐☐☐
W28OEM-A-44MS3PROULTIMA-A-260.5☐☐☐☐☐☐☐
W29SP-0V-1MS3PROULTIMA-A-270.5☐☐☐☐☐☐☐
W30OEM-A-34MS3PROULTIMA-A-310.5☐☐☐☐☐☐☐
W31OEM-A-8MS3PROULTIMA-B-130.5☐☐☐☐☐☐☐
W32OEM-A-60MS3PROULTIMA-B-140.5☐☐☐☐☐☐☐
W33OEM-A-52MS3PROULTIMA-B-150.5☐☐☐☐☐☐☐
W34OEM-A-24MS3PROULTIMA-A-30.5☐☐☐☐☐☐☐
W35OEM-A-3MS3PROULTIMA-A-40.5☐☐☐☐☐☐☐
W36OEM-A-26MS3PROULTIMA-B-10.5☐☐☐☐☐☐☐
W37OEM-A-4MS3PROULTIMA-B-100.5☐☐☐☐☐☐☐
W38OEM-A-25MS3PROULTIMA-B-110.5☐☐☐☐☐☐☐
W39OEM-A-2MS3PROULTIMA-B-120.5☐☐☐☐☐☐☐
W40OEM-A-38MS3PROULTIMA-B-190.5☐☐☐☐☐☐☐
W41OEM-A-17MS3PROULTIMA-A-190.5☐☐☐☐☐☐☐
W42OEM-A-40MS3PROULTIMA-A-90.5☐☐☐☐☐☐☐
W43OEM-A-14MS3PROULTIMA-A-110.5☐☐☐☐☐☐☐
W44OEM-A-49MS3PROULTIMA-A-280.5☐☐☐☐☐☐☐
W45OEM-A-6MS3PROULTIMA-A-140.5☐☐☐☐☐☐☐
W46OEM-A-9MS3PROULTIMA-C-40.5☐☐☐☐☐☐☐
W47OEM-A-27MS3PROULTIMA-A-290.5☐☐☐☐☐☐☐
W48OEM-A-31MS3PROULTIMA-C-30.5☐☐☐☐☐☐☐
W49OEM-A-5MS3PROULTIMA-A-300.5☐☐☐☐☐☐☐
W50OEM-A-53MS3PROULTIMA-C-20.5☐☐☐☐☐☐☐
W51OEM-A-22MS3PROULTIMA-A-240.5☐☐☐☐☐☐☐
W52OEM-A-51MS3PROULTIMA-C-10.5☐☐☐☐☐☐☐
W53OEM-A-20MS3PROULTIMA-A-250.5☐☐☐☐☐☐☐
W54OEM-A-15MS3PROULTIMA-A-100.5☐☐☐☐☐☐☐
W55OEM-A-36MS3PROULTIMA-A-200.5☐☐☐☐☐☐☐
W56OEM-A-65MS3PROULTIMA-B-280.5☐☐☐☐☐☐☐
W57OEM-A-37MS3PROULTIMA-A-320.5☐☐☐☐☐☐☐
W58OEM-A-39MS3PROULTIMA-B-200.5☐☐☐☐☐☐☐

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
1MS3PROULTIMA-A-13MS3PROULTIMA-A-35open (OL)power ground must not touch +12 V supply
2MS3PROULTIMA-A-13MS3PROULTIMA-A-8open (OL)power ground must not touch 5 V sensor reference
3MS3PROULTIMA-A-13MS3PROULTIMA-C-23open (OL)power ground must not touch +12 V supply
4MS3PROULTIMA-A-15MS3PROULTIMA-A-35open (OL)sensor ground must not touch +12 V supply
5MS3PROULTIMA-A-15MS3PROULTIMA-A-8open (OL)sensor ground must not touch 5 V sensor reference
6MS3PROULTIMA-A-15MS3PROULTIMA-C-23open (OL)sensor ground must not touch +12 V supply
7MS3PROULTIMA-A-35MS3PROULTIMA-A-8open (OL)+12 V supply must not touch 5 V sensor reference
8MS3PROULTIMA-A-8MS3PROULTIMA-C-23open (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

MS3PROULTIMA-AMS3PROULTIMA-BMS3PROULTIMA-COEM-ASP-0VSP-14VSP-GND

Connectors

MS3PROULTIMA-A

CavityFunctionSignalWireColourGauge (mm²)DestinationTerminalSealPlug
1High current out 1————————
10MAT in—W54—0.5OEM-A-15———
11CLT in—W43—0.5OEM-A-14———
12Analog In 6————————
13Power ground—W9—0.85SP-GND-1———
14PWM / Idle Out 1—W45—0.5OEM-A-6———
15CKP−—W27—0.5SP-0V-1———
16Logic ground—W18—0.5SP-0V-1———
17Analog In 7————————
18Sensor return—W19—0.5SP-0V-1———
19Analog in 1—W41—0.5OEM-A-17———
2High current out 2————————
20Analog in 2—W55—0.5OEM-A-36———
21Analog in 3————————
22Analog In 4————————
23Analog In 5————————
24Tach out—W51—0.5OEM-A-22———
25O2 in—W53—0.5OEM-A-20———
26CMP+—W28—0.5OEM-A-44———
27CMP−—W29—0.5SP-0V-1———
28Fuel pump relay out—W44—0.5OEM-A-49———
29PWM out 2—W47—0.5OEM-A-27———
3Injector out J—W34—0.5OEM-A-24———
30PWM out 3—W49—0.5OEM-A-5———
31Knock in 1—W30—0.5OEM-A-34———
32Digital switched in 1—W57—0.5OEM-A-37———
33CAN L————————
34CAN H————————
3512V+ switched power in—W2—0.85SP-14V-1———
4Injector out I—W35—0.5OEM-A-3———
5High current out 3————————
6CKP+—W26—0.5OEM-A-68———
7Knock In 2————————
85V+ VREF out 1—W25—0.5OEM-A-41———
9TPS in—W42—0.5OEM-A-40———

MS3PROULTIMA-B

CavityFunctionSignalWireColourGauge (mm²)DestinationTerminalSealPlug
1Injector out A—W36—0.5OEM-A-26———
10Injector out F—W37—0.5OEM-A-4———
11Injector out G—W38—0.5OEM-A-25———
12Injector out H—W39—0.5OEM-A-2———
13Spark out G—W31—0.5OEM-A-8———
14Spark out E—W32—0.5OEM-A-60———
15Spark out C—W33—0.5OEM-A-52———
16Spark out H————————
17Digital frequency in 2————————
18Ground—W10—0.85SP-GND-1———
19Digital switched 12V in—W40—0.5OEM-A-38———
2Injector out B————————
20Digital switched in 2—W58—0.5OEM-A-39———
21Digital frequency in 3————————
22Digital Frequency in 3 VR+————————
23Digital Frequency In 3 VR−————————
24Spark out F————————
25Spark out B————————
26Spark out D————————
27Spark out A————————
28Digital frequency in 1—W56—0.5OEM-A-65———
29Digital switched in 3————————
3Ground—W11—0.85SP-GND-1———
30Stepper IAC out 1B————————
31Stepper IAC out 1A————————
32Stepper IAC out 2A————————
33Stepper IAC out 2B————————
34Digital Frequency in 1 VR+————————
35Digital Frequency in 1 VR−————————
4Injector out C————————
5Ground—W12—0.85SP-GND-1———
6Injector out D————————
7Ground—W13—0.85SP-GND-1———
8Injector out E————————
9Ground—W14—0.85SP-GND-1———

MS3PROULTIMA-C

CavityFunctionSignalWireColourGauge (mm²)DestinationTerminalSealPlug
1PWM out 5—W52—0.5OEM-A-51———
10Digital switched in 5————————
11Digital switched in 4————————
12Digital I/O 5————————
13Digital I/O 3————————
14Digital I/O 1————————
155V+ VREF out 2————————
16Fuel only battery 12V+————————
17Sensor return—W20—0.5SP-0V-1———
18Sensor return—W21—0.5SP-0V-1———
19Sensor return—W22—0.5SP-0V-1———
2PWM out 4—W50—0.5OEM-A-53———
20Sensor return—W23—0.5SP-0V-1———
21Sensor return—W24—0.5SP-0V-1———
225V+ VREF out 1————————
23Keep alive power—W3—0.85OEM-A-54———
3Digital out 2—W48—0.5OEM-A-31———
4Digital out 1—W46—0.5OEM-A-9———
5Digital I/O 4————————
6Digital I/O 2————————
7Analog in 8————————
85V+ VREF out 2————————
9Fuel only coil negative————————

OEM-A

CavityFunctionSignalWireColourGauge (mm²)DestinationTerminalSealPlug
1Ground (E-1)—W4—0.85SP-GND-1———
10Ground (OBD1 EGR enable)—W5—0.85SP-GND-1———
14Coolant temperature (CLT)—W43—0.5MS3PROULTIMA-A-11———
15EGR temperature sensor—W54—0.5MS3PROULTIMA-A-10———
16MAF ground—W15—0.5SP-0V-1———
17MAF signal—W41—0.5MS3PROULTIMA-A-19———
2Injector 6 (cyl 6)—W39—0.5MS3PROULTIMA-B-12———
20O2 sensor 1 (primary)—W53—0.5MS3PROULTIMA-A-25———
21Diagnostic L-line————————
22Tachometer output—W51—0.5MS3PROULTIMA-A-24———
23ECU main power (from engine-electronics relay)—W1—0.85SP-14V-1———
24Injector 1 (cyl 1)—W34—0.5MS3PROULTIMA-A-3———
25Injector 5 (cyl 5)—W38—0.5MS3PROULTIMA-B-11———
26Injector 3 (cyl 3)—W36—0.5MS3PROULTIMA-B-1———
27Idle air control valve—W47—0.5MS3PROULTIMA-A-29———
3Injector 2 (cyl 2)—W35—0.5MS3PROULTIMA-A-4———
31EVAP canister purge valve—W48—0.5MS3PROULTIMA-C-3———
33Sensor ground bus—W16—0.5SP-0V-1———
34Knock sensor 1—W30—0.5MS3PROULTIMA-A-31———
36Intake air temperature (IAT)—W55—0.5MS3PROULTIMA-A-20———
37A/C compressor switch—W57—0.5MS3PROULTIMA-A-32———
38Ignition switch (run/start)—W40—0.5MS3PROULTIMA-B-19———
39A/C switch (cabin)—W58—0.5MS3PROULTIMA-B-20———
4Injector 4 (cyl 4)—W37—0.5MS3PROULTIMA-B-10———
40Throttle position sensor 1—W42—0.5MS3PROULTIMA-A-9———
41TPS power (+5V)—W25—0.5MS3PROULTIMA-A-8———
43Diagnostic K-line————————
44Camshaft position sensor (G40)—W28—0.5MS3PROULTIMA-A-26———
49Secondary air injection relay control—W44—0.5MS3PROULTIMA-A-28———
5Check engine light (MIL)—W49—0.5MS3PROULTIMA-A-30———
51MFA fuel-consumption signal—W52—0.5MS3PROULTIMA-C-1———
52Ignition coil 4 (coil pack pin 4)—W33—0.5MS3PROULTIMA-B-15———
53Idle air control valve (2nd)—W50—0.5MS3PROULTIMA-C-2———
54Battery constant (+12V)—W3—0.85MS3PROULTIMA-C-23———
55Ground (E-3)—W6—0.85SP-GND-1———
56Ground (E-4)—W7—0.85SP-GND-1———
59Mass airflow sensor (5th terminal)————————
6Fuel pump relay control—W45—0.5MS3PROULTIMA-A-14———
60Ignition coil 3 (coil pack pin 3)—W32—0.5MS3PROULTIMA-B-14———
65Vehicle speed sensor (VSS)—W56—0.5MS3PROULTIMA-B-28———
67Crank sensor return (VR-)—W17—0.5SP-0V-1———
68Crank position sensor (G28, VR+)—W26—0.5MS3PROULTIMA-A-6———
7Ground (E-2)—W8—0.85SP-GND-1———
8Ignition coil 2 (coil pack pin 2)—W31—0.5MS3PROULTIMA-B-13———
9Engine electronics relay control—W46—0.5MS3PROULTIMA-C-4———

SP-0V

CavityFunctionSignalWireColourGauge (mm²)DestinationTerminalSealPlug
1——W15—0.5OEM-A-16———
1——W16—0.5OEM-A-33———
1——W17—0.5OEM-A-67———
1——W18—0.5MS3PROULTIMA-A-16———
1——W19—0.5MS3PROULTIMA-A-18———
1——W20—0.5MS3PROULTIMA-C-17———
1——W21—0.5MS3PROULTIMA-C-18———
1——W22—0.5MS3PROULTIMA-C-19———
1——W23—0.5MS3PROULTIMA-C-20———
1——W24—0.5MS3PROULTIMA-C-21———
1——W27—0.5MS3PROULTIMA-A-15———
1——W29—0.5MS3PROULTIMA-A-27———

SP-14V

CavityFunctionSignalWireColourGauge (mm²)DestinationTerminalSealPlug
1——W1—0.85OEM-A-23———
1——W2—0.85MS3PROULTIMA-A-35———

SP-GND

CavityFunctionSignalWireColourGauge (mm²)DestinationTerminalSealPlug
1——W4—0.85OEM-A-1———
1——W5—0.85OEM-A-10———
1——W6—0.85OEM-A-55———
1——W7—0.85OEM-A-56———
1——W8—0.85OEM-A-7———
1——W9—0.85MS3PROULTIMA-A-13———
1——W10—0.85MS3PROULTIMA-B-18———
1——W11—0.85MS3PROULTIMA-B-3———
1——W12—0.85MS3PROULTIMA-B-5———
1——W13—0.85MS3PROULTIMA-B-7———
1——W14—0.85MS3PROULTIMA-B-9———

Pin map

OEM pointOEM functionOEM familyTarget pointTarget functionTarget familyWire colourEvidence
OEM-A-1Ground (E-1)groundMS3PROULTIMA-A-13 + MS3PROULTIMA-B-18 + MS3PROULTIMA-B-3 + MS3PROULTIMA-B-5 + MS3PROULTIMA-B-7 + MS3PROULTIMA-B-9Power ground + Ground + Ground + Ground + Ground + Groundgroundsingle_source
OEM-A-10Ground (OBD1 EGR enable)groundMS3PROULTIMA-A-13 + MS3PROULTIMA-B-18 + MS3PROULTIMA-B-3 + MS3PROULTIMA-B-5 + MS3PROULTIMA-B-7 + MS3PROULTIMA-B-9Power ground + Ground + Ground + Ground + Ground + Groundgroundsingle_source
OEM-A-14Coolant temperature (CLT)temp_inMS3PROULTIMA-A-11CLT intemp_insingle_source
OEM-A-15EGR temperature sensortemp_inMS3PROULTIMA-A-10MAT intemp_insingle_source
OEM-A-16MAF groundsensor_groundMS3PROULTIMA-A-15 + MS3PROULTIMA-A-16 + MS3PROULTIMA-A-18 + MS3PROULTIMA-A-27 + MS3PROULTIMA-C-17 + MS3PROULTIMA-C-18 + MS3PROULTIMA-C-19 + MS3PROULTIMA-C-20 + MS3PROULTIMA-C-21CKP− + Logic ground + Sensor return + CMP− + Sensor return + Sensor return + Sensor return + Sensor return + Sensor returnsensor_ground + trigger_insingle_source
OEM-A-17MAF signalanalog_inMS3PROULTIMA-A-19Analog in 1analog_insingle_source
OEM-A-2Injector 6 (cyl 6)injector_outMS3PROULTIMA-B-12Injector out Hinjector_outsingle_source
OEM-A-20O2 sensor 1 (primary)lambda_nb_inMS3PROULTIMA-A-25O2 inlambda_nb_insingle_source
OEM-A-21Diagnostic L-lineserial———single_source
OEM-A-22Tachometer outputtacho_outMS3PROULTIMA-A-24Tach outtacho_outsingle_source
OEM-A-23ECU main power (from engine-electronics relay)power_inMS3PROULTIMA-A-3512V+ switched power inpower_insingle_source
OEM-A-24Injector 1 (cyl 1)injector_outMS3PROULTIMA-A-3Injector out Jinjector_outsingle_source
OEM-A-25Injector 5 (cyl 5)injector_outMS3PROULTIMA-B-11Injector out Ginjector_outsingle_source
OEM-A-26Injector 3 (cyl 3)injector_outMS3PROULTIMA-B-1Injector out Ainjector_outsingle_source
OEM-A-27Idle air control valvelow_side_outMS3PROULTIMA-A-29PWM out 2low_side_outsingle_source
OEM-A-3Injector 2 (cyl 2)injector_outMS3PROULTIMA-A-4Injector out Iinjector_outsingle_source
OEM-A-31EVAP canister purge valvelow_side_outMS3PROULTIMA-C-3Digital out 2low_side_outsingle_source
OEM-A-33Sensor ground bussensor_groundMS3PROULTIMA-A-15 + MS3PROULTIMA-A-16 + MS3PROULTIMA-A-18 + MS3PROULTIMA-A-27 + MS3PROULTIMA-C-17 + MS3PROULTIMA-C-18 + MS3PROULTIMA-C-19 + MS3PROULTIMA-C-20 + MS3PROULTIMA-C-21CKP− + Logic ground + Sensor return + CMP− + Sensor return + Sensor return + Sensor return + Sensor return + Sensor returnsensor_ground + trigger_insingle_source
OEM-A-34Knock sensor 1knock_inMS3PROULTIMA-A-31Knock in 1knock_insingle_source
OEM-A-36Intake air temperature (IAT)temp_inMS3PROULTIMA-A-20Analog in 2analog_insingle_source
OEM-A-37A/C compressor switchdigital_inMS3PROULTIMA-A-32Digital switched in 1digital_insingle_source
OEM-A-38Ignition switch (run/start)digital_inMS3PROULTIMA-B-19Digital switched 12V indigital_insingle_source
OEM-A-39A/C switch (cabin)digital_inMS3PROULTIMA-B-20Digital switched in 2digital_insingle_source
OEM-A-4Injector 4 (cyl 4)injector_outMS3PROULTIMA-B-10Injector out Finjector_outsingle_source
OEM-A-40Throttle position sensor 1analog_inMS3PROULTIMA-A-9TPS inanalog_insingle_source
OEM-A-41TPS power (+5V)vrefMS3PROULTIMA-A-85V+ VREF out 1vrefsingle_source
OEM-A-43Diagnostic K-lineserial———single_source
OEM-A-44Camshaft position sensor (G40)trigger_inMS3PROULTIMA-A-26CMP+trigger_insingle_source
OEM-A-49Secondary air injection relay controllow_side_outMS3PROULTIMA-A-28Fuel pump relay outlow_side_outsingle_source
OEM-A-5Check engine light (MIL)low_side_outMS3PROULTIMA-A-30PWM out 3low_side_outsingle_source
OEM-A-51MFA fuel-consumption signaltacho_outMS3PROULTIMA-C-1PWM out 5low_side_outsingle_source
OEM-A-52Ignition coil 4 (coil pack pin 4)ignition_outMS3PROULTIMA-B-15Spark out Cignition_outsingle_source
OEM-A-53Idle air control valve (2nd)low_side_outMS3PROULTIMA-C-2PWM out 4low_side_outsingle_source
OEM-A-54Battery constant (+12V)power_inMS3PROULTIMA-C-23Keep alive powerpower_insingle_source
OEM-A-55Ground (E-3)groundMS3PROULTIMA-A-13 + MS3PROULTIMA-B-18 + MS3PROULTIMA-B-3 + MS3PROULTIMA-B-5 + MS3PROULTIMA-B-7 + MS3PROULTIMA-B-9Power ground + Ground + Ground + Ground + Ground + Groundgroundsingle_source
OEM-A-56Ground (E-4)groundMS3PROULTIMA-A-13 + MS3PROULTIMA-B-18 + MS3PROULTIMA-B-3 + MS3PROULTIMA-B-5 + MS3PROULTIMA-B-7 + MS3PROULTIMA-B-9Power ground + Ground + Ground + Ground + Ground + Groundgroundsingle_source
OEM-A-59Mass airflow sensor (5th terminal)sensor_out———single_source
OEM-A-6Fuel pump relay controllow_side_outMS3PROULTIMA-A-14PWM / Idle Out 1low_side_outsingle_source
OEM-A-60Ignition coil 3 (coil pack pin 3)ignition_outMS3PROULTIMA-B-14Spark out Eignition_outsingle_source
OEM-A-65Vehicle speed sensor (VSS)digital_inMS3PROULTIMA-B-28Digital frequency in 1digital_insingle_source
OEM-A-67Crank sensor return (VR-)sensor_groundMS3PROULTIMA-A-15 + MS3PROULTIMA-A-16 + MS3PROULTIMA-A-18 + MS3PROULTIMA-A-27 + MS3PROULTIMA-C-17 + MS3PROULTIMA-C-18 + MS3PROULTIMA-C-19 + MS3PROULTIMA-C-20 + MS3PROULTIMA-C-21CKP− + Logic ground + Sensor return + CMP− + Sensor return + Sensor return + Sensor return + Sensor return + Sensor returnsensor_ground + trigger_insingle_source
OEM-A-68Crank position sensor (G28, VR+)trigger_inMS3PROULTIMA-A-6CKP+trigger_insingle_source
OEM-A-7Ground (E-2)groundMS3PROULTIMA-A-13 + MS3PROULTIMA-B-18 + MS3PROULTIMA-B-3 + MS3PROULTIMA-B-5 + MS3PROULTIMA-B-7 + MS3PROULTIMA-B-9Power ground + Ground + Ground + Ground + Ground + Groundgroundsingle_source
OEM-A-8Ignition coil 2 (coil pack pin 2)ignition_outMS3PROULTIMA-B-13Spark out Gignition_outsingle_source
OEM-A-9Engine electronics relay controllow_side_outMS3PROULTIMA-C-4Digital out 1low_side_outsingle_source

Cut list

WireFromToGauge (mm²)ColourLengthSignalIdent
W1OEM-A-23SP-14V-10.85no routeECU main power (from engine-electronics relay)—
W2SP-14V-1MS3PROULTIMA-A-350.85no route12V+ switched power in—
W3OEM-A-54MS3PROULTIMA-C-230.85no routeBattery constant (+12V)—
W4OEM-A-1SP-GND-10.85no routeGround (E-1)—
W5OEM-A-10SP-GND-10.85no routeGround (OBD1 EGR enable)—
W6OEM-A-55SP-GND-10.85no routeGround (E-3)—
W7OEM-A-56SP-GND-10.85no routeGround (E-4)—
W8OEM-A-7SP-GND-10.85no routeGround (E-2)—
W9SP-GND-1MS3PROULTIMA-A-130.85no routePower ground—
W10SP-GND-1MS3PROULTIMA-B-180.85no routeGround—
W11SP-GND-1MS3PROULTIMA-B-30.85no routeGround—
W12SP-GND-1MS3PROULTIMA-B-50.85no routeGround—
W13SP-GND-1MS3PROULTIMA-B-70.85no routeGround—
W14SP-GND-1MS3PROULTIMA-B-90.85no routeGround—
W15OEM-A-16SP-0V-10.5no routeMAF ground—
W16OEM-A-33SP-0V-10.5no routeSensor ground bus—
W17OEM-A-67SP-0V-10.5no routeCrank sensor return (VR-)—
W18SP-0V-1MS3PROULTIMA-A-160.5no routeLogic ground—
W19SP-0V-1MS3PROULTIMA-A-180.5no routeSensor return—
W20SP-0V-1MS3PROULTIMA-C-170.5no routeSensor return—
W21SP-0V-1MS3PROULTIMA-C-180.5no routeSensor return—
W22SP-0V-1MS3PROULTIMA-C-190.5no routeSensor return—
W23SP-0V-1MS3PROULTIMA-C-200.5no routeSensor return—
W24SP-0V-1MS3PROULTIMA-C-210.5no routeSensor return—
W25OEM-A-41MS3PROULTIMA-A-80.5no routeTPS power (+5V)—
W26OEM-A-68MS3PROULTIMA-A-60.5no routeCrank position sensor (G28, VR+)—
W27SP-0V-1MS3PROULTIMA-A-150.5no routeCKP−—
W28OEM-A-44MS3PROULTIMA-A-260.5no routeCamshaft position sensor (G40)—
W29SP-0V-1MS3PROULTIMA-A-270.5no routeCMP−—
W30OEM-A-34MS3PROULTIMA-A-310.5no routeKnock sensor 1—
W31OEM-A-8MS3PROULTIMA-B-130.5no routeIgnition coil 2 (coil pack pin 2)—
W32OEM-A-60MS3PROULTIMA-B-140.5no routeIgnition coil 3 (coil pack pin 3)—
W33OEM-A-52MS3PROULTIMA-B-150.5no routeIgnition coil 4 (coil pack pin 4)—
W34OEM-A-24MS3PROULTIMA-A-30.5no routeInjector 1 (cyl 1)—
W35OEM-A-3MS3PROULTIMA-A-40.5no routeInjector 2 (cyl 2)—
W36OEM-A-26MS3PROULTIMA-B-10.5no routeInjector 3 (cyl 3)—
W37OEM-A-4MS3PROULTIMA-B-100.5no routeInjector 4 (cyl 4)—
W38OEM-A-25MS3PROULTIMA-B-110.5no routeInjector 5 (cyl 5)—
W39OEM-A-2MS3PROULTIMA-B-120.5no routeInjector 6 (cyl 6)—
W40OEM-A-38MS3PROULTIMA-B-190.5no routeIgnition switch (run/start)—
W41OEM-A-17MS3PROULTIMA-A-190.5no routeMAF signal—
W42OEM-A-40MS3PROULTIMA-A-90.5no routeThrottle position sensor 1—
W43OEM-A-14MS3PROULTIMA-A-110.5no routeCoolant temperature (CLT)—
W44OEM-A-49MS3PROULTIMA-A-280.5no routeSecondary air injection relay control—
W45OEM-A-6MS3PROULTIMA-A-140.5no routeFuel pump relay control—
W46OEM-A-9MS3PROULTIMA-C-40.5no routeEngine electronics relay control—
W47OEM-A-27MS3PROULTIMA-A-290.5no routeIdle air control valve—
W48OEM-A-31MS3PROULTIMA-C-30.5no routeEVAP canister purge valve—
W49OEM-A-5MS3PROULTIMA-A-300.5no routeCheck engine light (MIL)—
W50OEM-A-53MS3PROULTIMA-C-20.5no routeIdle air control valve (2nd)—
W51OEM-A-22MS3PROULTIMA-A-240.5no routeTachometer output—
W52OEM-A-51MS3PROULTIMA-C-10.5no routeMFA fuel-consumption signal—
W53OEM-A-20MS3PROULTIMA-A-250.5no routeO2 sensor 1 (primary)—
W54OEM-A-15MS3PROULTIMA-A-100.5no routeEGR temperature sensor—
W55OEM-A-36MS3PROULTIMA-A-200.5no routeIntake air temperature (IAT)—
W56OEM-A-65MS3PROULTIMA-B-280.5no routeVehicle speed sensor (VSS)—
W57OEM-A-37MS3PROULTIMA-A-320.5no routeA/C compressor switch—
W58OEM-A-39MS3PROULTIMA-B-200.5no routeA/C switch (cabin)—

Bill of materials

CategoryPart numberManufacturerDescriptionQtyUnit

ECU setup sheet

RoleEngine refEngine signalSensorECU pointECU functionECU classSetup flag
No configured channels.

Findings

Open (4)

SeverityCodeSubjectMessage
infoNET_FAMILYMS3PROULTIMA-A-18 ↔ MS3PROULTIMA-A-27MS3PROULTIMA-A-18 "Sensor return" [sensor_ground] is wired to MS3PROULTIMA-A-27 "CMP−" [trigger_in]. Trigger return tied to sensor/trigger ground: correct for single-ended trigger inputs.
infoNET_FAMILYOEM-A-36 ↔ MS3PROULTIMA-A-20OEM-A-36 "Intake air temperature (IAT)" [temp_in] is wired to MS3PROULTIMA-A-20 "Analog in 2" [analog_in]. Thermistor on a plain analog input needs a pull-up; check the channel can enable one.
infoNET_FAMILYOEM-A-51 ↔ MS3PROULTIMA-C-1OEM-A-51 "MFA fuel-consumption signal" [tacho_out] is wired to MS3PROULTIMA-C-1 "PWM out 5" [low_side_out]. Tacho as a low-side output: check the tach needs a pull-up.
infoUNMAPPEDOEM3 optional OEM pins are not mapped: OEM-A-21 Diagnostic L-line; OEM-A-43 Diagnostic K-line; OEM-A-59 Mass airflow sensor (5th terminal)

Accepted (0)

CodeSubjectReasonBy

Notes

Auto-mapped by auto_map() from the library pin data on 2026-10-11. Review every wire against both manuals before building. Not wired: - OEM-A 21: Diagnostic L-line: no free k_line on AMP EFI MS3Pro Ultimate - OEM-A 43: Diagnostic K-line: no free k_line on AMP EFI MS3Pro Ultimate - OEM-A 59: Mass airflow sensor (5th terminal): no rule for class sensor_signal; wire by hand

Sources

ReliabilityKindTitleURLArchiveCapturedSHA-256
4vendor_docAMP EFI: MS3Pro Ultimate manual (v1.210, fw 1.5.2) pinout tableshttps://cdn.shopify.com/s/files/1/0960/0014/7754/files/MS3Pro_User_Manual_Firmware_1.5.2_ULTIMATE.pdf?v=1760706068archive2026-10-0571ed7ed81581
2community_copya2resource: VR6/ABA Motronic M2.9 (OBD1) engine control unit pinouthttp://www.a2resource.com/electrical/management/motronicvr6aba.html———