Applications Nissan QR25DE
Draft. Trigger offset has not been confirmed on a running Race Core install. Pins marked TBD are unknown — do not guess them. A wrong decoder or firing order can destroy the engine.
Nissan QR25DE
2.5 L four in the Sentra, X-Trail and Frontier. rusEFI has a named crank decoder, NISSAN_QR25. Use that mode. Do not borrow a Dodge Neon or SRT-4 decoder because a scope looked similar — those are different patterns, and the QR25 has its own.
Recommended: F7, V4 or Micro Core for four high-Z injectors and four logic coils on a cable car. DBW variants need F7 H-bridges. Cam is required for sequential.
Status: draft. Trigger offset has not been confirmed on a running Race Core install.
- Cylinders: 4
- Displacement: 2488 cc
- Firing order: 1-3-4-2
- Orientation: Cylinder 1 at the front / chain end. Firing order 1-3-4-2.
Variants
| Variant | Years | Trigger | Notes |
|---|---|---|---|
| QR25DE | 2001– | NISSAN_QR25 crank + cam | Sentra, X-Trail, Frontier. Port injection. Cable or DBW by year. |
Recommended pin assignment (Race Core F7)
Pins below are the library default Race Core F7 map — the same AMPSEAL landings as the verified 1UZ-FE, 2JZ-GTE and LS1 notes. Core EFI V4 and Micro Core cavity numbers are TBD. If a pin is not in this table, it is TBD. Do not guess a spare.
| Pin | TunerStudio | Function |
|---|---|---|
| B10 | Digital 1 | Crank Hall |
| B1 | Digital 2 | Cam Hall |
| A3 | Lowside 1 | Injector cylinder 1 |
| A15 | Lowside 2 | Injector cylinder 2 |
| A4 | Lowside 3 | Injector cylinder 3 |
| A16 | Lowside 4 | Injector cylinder 4 |
| A35 | Ign 1 | Cyl 1 logic coil |
| A34 | Ign 2 | Cyl 2 logic coil |
| A22 | Ign 3 | Cyl 3 logic coil |
| A33 | Ign 4 | Cyl 4 logic coil |
| A2 | Highside 1 | Cam oil-control valve (PWM) |
| B7/B6 + B15/B8 | ETB 1 ± / ETB 2 ± | DBW motor. Not a stepper as well. Pedal and TPS tracks: follow the APP and ETB notes |
| C20 | Analog Temp 3 | CLT |
| C30 | Analog Temp 2 | IAT |
| C13 | Analog Volt 1 | MAP 0–5 V |
| C24 | Analog Volt 2 | TPS 1 |
| C34 | Knock 1 | Knock |
| A20 | Lowside 10 | Fuel-pump relay coil |
| A21 | Lowside 12 | Main-relay coil |
| A12 | Lowside 15 | Radiator-fan relay coil |
| B17 / B16 | CAN 1 H / L | Dash / wideband |
| B18 | Battery Sense | Ignition-switched 12 V (5 A fuse) |
| B23 | +12 V MR | Main-relay 12 V into ECU |
| A17 A18 A24 B14 B19 B20 | Power GND | Engine block → battery − |
| C9 / C21 / C32 | 5 V Sens 1 | MAP, TPS, pedal 1 |
| C1–C8, C29, C31 | Sensor GND | 0–5 V and thermistor returns |
Trigger
TunerStudio wheel type NISSAN_QR25. Confirm with a composite log before you enable spark. A 36-1 conversion is the fallback if the OEM wheel will not sync, not the first guess.
Crank
| Decoder | NISSAN_QR25 on Digital 1 if the sensor is Hall. VR 1 if you have fitted a VR. |
| Not this | Dodge Neon 1995, Neon 2003, or a generic 36-1. |
Cam
| Sync | Digital 2. Required for sequential and for any cam-phaser closed loop. |
TunerStudio
| Setting | Value |
|---|---|
| Trigger / wheel type | NISSAN_QR25 |
| Use only rising edge | Hall: as logged. VR: typically yes on MAX992x |
| Invert primary | No — swap VR wires first |
| Firing order | 1-3-4-2 |
Offset: Light on cylinder 1.
Injection
High-Z port injectors, sequential four. Some QR engines are returnless; add a return if you raise fuel pressure for boost.
| Impedance | Meter. Saturated drivers only. |
Ignition
Four logic coils, Ign 1–4, dwell 2.0–2.5 ms. Firing order in software.
| Dumb coils | Not on these outputs. |
Idle
Identify cable idle valve versus DBW. DBW uses the H-bridges and the ETB note. Idle-valve pin on a cable car is TBD.
First start
- Load the matching variant configuration in TunerStudio before the harness is live — injectors and coils stay disconnected until the decoder is confirmed.
- Fuel pump fuse out. Coils unplugged or spark outputs disabled. Crank. Open Diagnostics → composite / high-speed logger.
- Confirm crank teeth are even, the missing-tooth (or named pattern) is a single clean gap, and cam is one pulse per two crank revolutions for sequential four-stroke.
- RPM during cranking should sit in the 150–350 rpm band. 0 rpm or 12,000 rpm means the decoder is lost — polarity or wheel type, not offset.
- Lock timing to a fixed 10° (idle control off). Timing light on cylinder 1. Change trigger offset until the damper agrees with 10°.
- Recheck at ~3,000 rpm. If timing walks with RPM, it is VR polarity, a delayed Hall, or the wrong decoder — not offset.
- Enable spark. Confirm a healthy burn (timing light or plug colour) with fuel still disabled.
- Enable fuel. Prime, then crank. Catch the first idle on a rich-safe VE, then lean toward stoich at idle.
- Only then enable closed-loop idle, VVT, boost and traction. A base map is a starting point, not a dyno tune.
A base map is a starting point, not a dyno tune.