Link G4+ Thunder is a 120-pin wire-in Link ECU on 4 connectors: A (34 pins), B (34 pins), C (26 pins) and D (26 pins). Link no longer makes it, so this page is for people who already own one or are buying used.
It has 8 injector outputs and 8 ignition outputs. The injector drivers are peak-and-hold, so low-impedance injectors run without a resistor pack. The ignition outputs are logic-level. Smart coils plug straight in; dumb coils need an igniter in between.
There are 2 dedicated trigger inputs, each happy with a VR or a Hall sensor. Two knock inputs cover both banks of a V engine. It has 2 onboard wideband controllers, so a sensor wires straight in.
It has H-bridge outputs labelled for an electronic throttle, so drive-by-wire runs from the ECU itself. Two CAN buses handle dashes, PDMs and expansion. Eight outputs can switch 12V as well as ground.
Spec sheet
| Connectors | A (34), B (34), C (26), D (26)120 pins in this profile |
|---|---|
| Injector outputs | 8peak-and-hold (low-impedance capable) |
| Ignition outputs | 8logic-level: smart coils, or an igniter for dumb coils |
| Dedicated trigger inputs | 2VR or Hall |
| Knock inputs | 2 |
| Onboard wideband controllers | 2 |
| Onboard MAP sensor | Not listed by the maker |
| CAN buses | 2one bus is reached through an adaptor cable |
| Drive-by-wire | Yes |
| High-side outputs | 8 |
| Half-bridge outputs | 4H-bridge pairs for a throttle motor or stepper |
| 5V sensor supply | 2 pins |
| Thermocouple (EGT) inputs | 2 |
Worth knowing
- Discontinued G4+ model with no G4X successor.
- Pin numbers are counted from Link's loom views (top-left = 1, left to right by row); check them against your own unit's documentation before wiring.
Which builds it suits
Of the 58 swap presets in the planner, 28 fit as they are and 29 fit with add-ons; 1 does not fit at all. The add-on it asks for most often is an external igniter. Where it falls short, it is usually not enough knock inputs. The planner fills anything a preset leaves open with its ordinary defaults, so your own build may land differently.
It runs the GM LS L76 (Gen4 6.0 alum), Nissan VR38DETT (R35 GT-R), Subaru EJ/FA EJ20 turbo single-AVCS (EJ207 v7-9) and Mazda Rotary 13B-MSP Renesis (RX-8 auto, 4-injector) presets with nothing added. The Ford Coyote 5.0 Gen2 (2015-17) needs an external igniter. The Nissan SR20DET (S14) needs an external igniter. It can't run the BMW S54 (3.2 NA I6, E46 M3): not enough knock inputs.
Fits as it is 28
- GM LS1 (Gen3 5.7 alum)
- GM LS6 (Gen3 5.7 alum)
- GM LS LQ4/LQ9 (Gen3 6.0 iron)
- GM LS2 (Gen4 6.0 alum)
- GM LS3 (Gen4 6.2 alum, car)
- GM LS L76 (Gen4 6.0 alum)
- GM LS L92 (Gen4 6.2 alum)
- GM LS LY6/L96 (Gen4 6.0 iron)
- GM LSA (Gen4 6.2 alum, S/C)
- Nissan RB25DET non-Neo S2 (R33, smart coils)
- Nissan RB25DET Neo (R34)
- Nissan RB26DETT (R34, smart coils)
- Nissan VR38DETT (R35 GT-R)
- Nissan SR20DET (S15)
- Nissan VQ35DE (base, 2003-04)
- Nissan VQ35DE Rev-Up (2005-06)
- Nissan VQ35HR (High-Rev, 2007+)
- Honda K20 (i-VTEC 2.0 NA)
- Honda K24 (i-VTEC 2.4 NA)
- Subaru EJ/FA EJ20 turbo single-AVCS (EJ207 v7-9)
- Subaru EJ/FA EJ20 turbo dual-AVCS (EJ207 GRB 2008+)
- Subaru EJ/FA EJ25 turbo single-AVCS (EJ257 2004-07)
- Subaru EJ/FA EJ25 turbo dual-AVCS (EJ257 2008+)
- Subaru EJ/FA FA20D (BRZ/86 NA)
- Mazda Rotary 13B-REW (FD RX-7)
- Mazda Rotary 13B-MSP Renesis (RX-8 manual, 6-injector)
- Mazda Rotary 13B-MSP Renesis (RX-8 auto, 4-injector)
- Mazda Rotary 20B (Eunos Cosmo 3-rotor)
Fits with add-ons 29
- Toyota 1JZ-GE distributor (NA, early) with an external igniter
- Toyota 1JZ-GE VVT-i (coil pack) with an external igniter
- Toyota 1JZ-GTE non-VVTi with an external igniter
- Toyota 1JZ-GTE VVTi with an external igniter
- Toyota 2JZ-GE distributor (NA, early) with an external igniter
- Toyota 2JZ-GE VVT-i (coil pack) with an external igniter
- Toyota 2JZ-GTE non-VVTi with an external igniter
- Toyota 2JZ-GTE VVTi with an external igniter
- GM LT1 (Gen5 6.2 alum) with a direct-injection driver module
- GM LT4 (Gen5 6.2 alum, S/C) with a direct-injection driver module
- Ford Coyote 5.0 Gen1 (2011-14) with an external igniter
- Ford Coyote 5.0 Gen2 (2015-17) with an external igniter
- Ford Coyote 5.0 Gen3 (2018-23) with an external igniter
- Ford Modular 4.6 2V (SOHC) with an external igniter
- Ford Modular 4.6 4V Cobra (NA, cable) with an external igniter
- Ford Modular 4.6 4V Terminator (S/C, cable) with an external igniter
- Ford Modular 5.4 4V Ford GT (S/C, cable) with an external igniter
- Ford Modular 5.4 4V GT500 (S/C, DBW) with an external igniter
- Ford Coyote Voodoo 5.2 (GT350, flat-plane) with an external igniter
- Ford Coyote Predator 5.2 (GT500, cross-plane, S/C) with an external igniter
- Ford Barra 4.0 NA (182/190/195) with an external igniter
- Ford Barra 4.0 Turbo (240T/245T/270T/310T/325T) with an external igniter
- Nissan RB20DET with an external igniter
- Nissan RB25DET non-Neo S1 (R33, dumb coils) with an external igniter
- Nissan RB26DETT (R32/R33, dumb coils) with an external igniter
- Nissan SR20DET (S13) with an external igniter
- Nissan SR20DET (S14) with an external igniter
- Subaru EJ/FA FA20DIT (WRX turbo 2015+) with a direct-injection driver module
- BMW N54 (3.0 twin-turbo I6) with a direct-injection driver module, an external igniter
Does not fit 1
- BMW S54 (3.2 NA I6, E46 M3) not enough knock inputs
Plan a build around the Link G4+ Thunder
Pin table
By connector: A carries 4 injector outputs, 4 ignition outputs and 2 trigger inputs; B carries 4 injector outputs, 4 ignition outputs and 2 knock inputs; C carries 6 digital inputs and 10 wideband pins; D carries 4 analog inputs, 2 H-bridge outputs and 2 CAN buses.
Show all 120 pins
| Pin | Function |
|---|---|
| A 1 | Injector drive 4 (spare may be aux output) |
| A 2 | Injector drive 3 (spare may be aux output) |
| A 3 | Injector drive 2 (spare may be aux output) |
| A 4 | Injector drive 1 (spare may be aux output) |
| A 5 | +14V supply feed to ECU |
| A 6 | +8V sensor supply out |
| A 7 | Shield ground |
| A 8 | Trigger 1 input (VR, Hall, optical or proximity) |
| A 9 | Trigger 2 input (VR, Hall, optical or proximity) |
| A 10 | Ignition drive 4, logic-level to igniter (spare may be aux output) |
| A 11 | Ignition drive 3, logic-level to igniter (spare may be aux output) |
| A 12 | Ignition drive 2, logic-level to igniter (spare may be aux output) |
| A 13 | Ignition drive 1, logic-level to igniter (spare may be aux output) |
| A 14 | Analog 0-5V input 4 |
| A 15 | Temp input 1, thermistor, selectable pull-up |
| A 16 | Temp input 2, thermistor, selectable pull-up |
| A 17 | Analog 0-5V input 1 |
| A 18 | Aux out 4: PWM/VVT/switching, flywheeled, low side only (high freq) |
| A 19 | Aux out 3: PWM/VVT/switching, flywheeled, low side only (high freq) |
| A 20 | Aux out 2: PWM/VVT/switching, flywheeled, low side only (high freq) |
| A 21 | Aux out 1: PWM/VVT/switching, flywheeled, low side only (high freq) |
| A 22 | Analog 0-5V input 2 |
| A 23 | DI 3: freq, switch or VVT cam position input |
| A 24 | Sensor ground out |
| A 25 | ECU power ground |
| A 26 | Aux out 8: PWM/VVT/switching, flywheeled, high or low side; stepper capable (PWM under 300 Hz) |
| A 27 | Aux out 7: PWM/VVT/switching, flywheeled, high or low side; stepper capable (PWM under 300 Hz) |
| A 28 | Aux out 6: PWM/VVT/switching, flywheeled, high or low side; stepper capable (PWM under 300 Hz) |
| A 29 | Aux out 5: PWM/VVT/switching, flywheeled, high or low side; stepper capable (PWM under 300 Hz) |
| A 30 | DI 1: freq, switch or VVT cam position input |
| A 31 | DI 2: freq, switch or VVT cam position input |
| A 32 | +5V sensor supply out (TPS, MAP) |
| A 33 | Analog 0-5V input 3 |
| A 34 | ECU power ground |
| B 1 | Injector drive 8 (spare may be aux output) |
| B 2 | Injector drive 7 (spare may be aux output) |
| B 3 | Injector drive 6 (spare may be aux output) |
| B 4 | Injector drive 5 (spare may be aux output) |
| B 5 | +14V supply for Aux 9/10 (e-throttle) |
| B 6 | Temp input 3, thermistor, NTC only |
| B 7 | Temp input 4, thermistor, NTC only |
| B 8 | Knock sensor input 2 |
| B 9 | Knock sensor input 1 |
| B 10 | Ignition drive 8, logic-level to igniter (spare may be aux output) |
| B 11 | Ignition drive 7, logic-level to igniter (spare may be aux output) |
| B 12 | Ignition drive 6, logic-level to igniter (spare may be aux output) |
| B 13 | Ignition drive 5, logic-level to igniter (spare may be aux output) |
| B 14 | Analog 0-5V input 12 |
| B 15 | Analog 0-5V input 6 |
| B 16 | Analog 0-5V input 7 |
| B 17 | Shield ground |
| B 18 | Aux out 9: E-throttle motor + or general output |
| B 19 | DI 6: freq or switch input |
| B 20 | DI 5: freq or switch input |
| B 21 | DI 4: freq, switch or VVT cam position input |
| B 22 | Sensor ground out |
| B 23 | Analog 0-5V input 8 |
| B 24 | Analog 0-5V input 9 |
| B 25 | ECU power ground |
| B 26 | Aux out 10: E-throttle motor - or general output |
| B 27 | DI 10: switch input only |
| B 28 | DI 9: switch input only |
| B 29 | DI 8: freq or switch input |
| B 30 | DI 7: freq or switch input |
| B 31 | Analog 0-5V input 10 |
| B 32 | Analog 0-5V input 11 |
| B 33 | Analog 0-5V input 5 |
| B 34 | ECU power ground |
| C 1 | Main relay control + |
| C 2 | Ignition drive Sw, logic-level to igniter (spare may be aux output) |
| C 3 | Wideband 1 LSU 4.9 MES line |
| C 4 | Wideband 1 LSU 4.9 APE line |
| C 5 | Wideband 1 LSU 4.9 IPE line |
| C 6 | Wideband 1 LSU 4.9 RE line |
| C 7 | Wideband 1 LSU 4.9 Heater line |
| C 8 | Main relay control - |
| C 9 | Wideband 2 LSU 4.9 MES line |
| C 10 | Wideband 2 LSU 4.9 APE line |
| C 11 | Wideband 2 LSU 4.9 IPE line |
| C 12 | Wideband 2 LSU 4.9 RE line |
| C 13 | Wideband 2 LSU 4.9 Heater line |
| C 14 | DI 11 + leg of differential pair, wheel speed / high freq or switch |
| C 15 | DI 12 + leg of differential pair, wheel speed / high freq or switch |
| C 16 | DI 13 + leg of differential pair, wheel speed / high freq or switch |
| C 17 | DI 14 + leg of differential pair, wheel speed / high freq or switch |
| C 18 | DI 15 + leg of differential pair, wheel speed / high freq or switch |
| C 19 | DI 16 + leg of differential pair, wheel speed / high freq or switch |
| C 20 | DI 11 - leg of differential pair, wheel speed / high freq or switch |
| C 21 | DI 12 - leg of differential pair, wheel speed / high freq or switch |
| C 22 | DI 13 - leg of differential pair, wheel speed / high freq or switch |
| C 23 | DI 14 - leg of differential pair, wheel speed / high freq or switch |
| C 24 | DI 15 - leg of differential pair, wheel speed / high freq or switch |
| C 25 | DI 16 - leg of differential pair, wheel speed / high freq or switch |
| C 26 | ECU power ground |
| D 1 | +14V supply for Aux 17-20 |
| D 2 | Aux out 19: general output, low or high side |
| D 3 | Aux out 20: general output, low or high side |
| D 4 | +5V sensor supply out (TPS, MAP) |
| D 5 | Sensor ground out |
| D 6 | K-type thermocouple 2 + leg |
| D 7 | K-type thermocouple 2 - leg |
| D 8 | Analog 0-5V input 13 (not for TPS, APS or MAP) |
| D 9 | Analog 0-5V input 14 (not for TPS, APS or MAP) |
| D 10 | Analog 0-5V input 15 (not for TPS, APS or MAP) |
| D 11 | Analog 0-5V input 16 (not for TPS, APS or MAP) |
| D 12 | K-type thermocouple 1 + leg |
| D 13 | K-type thermocouple 1 - leg |
| D 14 | Aux out 11: low-current low-side switch, no PWM |
| D 15 | Aux out 12: low-current low-side switch, no PWM |
| D 16 | Aux out 13: low-current low-side switch, no PWM |
| D 17 | Aux out 14: low-current low-side switch, no PWM |
| D 18 | Aux out 15: low-current low-side switch, no PWM |
| D 19 | Aux out 16: low-current low-side switch, no PWM |
| D 20 | Aux out 17: E-throttle 2 motor or general output, low or high side |
| D 21 | Aux out 18: E-throttle 2 motor or general output, low or high side |
| D 22 | CAN bus 2 H |
| D 23 | CAN bus 2 L |
| D 24 | CAN bus 1 H |
| D 25 | CAN bus 1 L |
| D 26 | ECU power ground |
Other Link ECUs
The closest Link unit is the Link G4+ Xtreme. Against it, this one has 2 wideband controllers (the G4+ Xtreme has 0) and 120 pins (the G4+ Xtreme has 69).
This pinout comes from Link's G4+ Thunder quick start guide, with pin numbers counted from its loom views. Check it against your own unit's documentation before you wire anything.
Source: Link documentation for the G4+ Thunder
Always verify against the manufacturer's manual and your tuner before wiring.