ECU
What is the ECU?[edit]
The ECU is the computer that manages your engine. The letters "ECU" stand for "Engine Control Unit". The ECU uses closed-loop control, a control scheme that monitors outputs of a system to control the inputs to a system, managing the emissions and fuel economy of the engine (as well as a host of other parameters). Gathering data from dozens of different sensors, the ECU knows everything from the coolant temperature to the amount of oxygen in the exhaust. With this data, it performs millions of calculations each second, including looking up values in tables, calculating the results of long equations to decide on the best spark timing and determining how long the fuel injector is open. The ECU does all of this to ensure the lowest emissions and best mileage.
RB20DET (NICS)[edit]
NICS
- Nissan Part # 23710-45L70
- Hitachi MEC-R50 - C (6Z01)
Main board: MEC-R50/R60/R61
- Main board contains
- CPU HD63B03XP (Motorola 6803 Clone)
- 42 Pin IO HD46510P (46510 Interface chip)
- 24 pin NEC D449C(A)-1 (2K RAM chip)
- 28 pin 27C128 EPROM chip (MEC-R50C 4GC520 containing program code and data)
- Second board is a knock sensor board and contains
- Mitsubishi M59203P
- HD14053BP chip
- 28 pin NEC D6503C(A)905 (only few pins connected? unsure of operation)
RB20DET (ECCS)[edit]
Manual Transmission, Front Wheel Drive*, RB20DET ECU (ECCS)
- Nissan Part # 23710 80S02
- Hitachi MEC-R47 (8704)
Main board: GE001282-2 MEC R40,41,42,43,44
- Main board contains
- CPU HD63B03XP (Motorola 6803 Clone)
- 24 pin NEC D449C(A)-1 (2K RAM chip)
- 28 pin 27C128 EPROM chip (MEC-R47C 8GC619 containing program code and maps)
- 42 Pin IO HD46510P (46510 Interface chip)
- Large Fujitsu custom chip MB62HB125
- Second board is a knock sensor board and contains
- Mitsubishi M59203P
- HD14053BP chip
- 1 x HA17903
- 2 x HA17904
* I'm unsure if FWD is correct?
RB20DET (ECCS Silvertop)[edit]
- Nissan Part # 23710 11U00
- Hitachi MEC-R212B (2919)
- Main board Hitachi GE002947-1 contains
- CPU HD63B03YCP (Motorola 6803 Clone in PGA package)
- Hitachi HD63140CP (Hitachi Universal Pulse Processor)
- NEC 65022L (A) 901 Matches to NEC 65022L or D65022L (Possibly RAM chip?)
- 28 PIN 27C256 EPROM chip (MEC-T212B 8RY34-09 Program code and maps)
- Second board is a knock sensor board and contains
- Mitsubishi M59203P
- HD14053BP chip
- 1 x HA17903
- 2 x HA17904
RB25DET[edit]
- Nissan Part # 23710 21U11
- Hitachi MEC-R531-A1 (3X19)
- Main board Hitachi GE211618-A contains
- MCU HD6475348CP10 (MEC-R531A 8HR1E-12 S) PGA chip
- This chip is a Hitachi MPU PLCC type H8/534 running at 10MHz used in the R33 Skyline
- It is 84 pins and has 32KB ROM and 32KB RAM E2ROM
CF79103FN MA (PGA chip)
No knock sensing board
RB30E Skyline[edit]
- Part # 23710-J7100 (Manual)
- Main board JECS A19-001-J20
- 40 Pin CPU HD6802 (Motorola 6802 Clone)
- 42 pin IO HD46510P (46510 Interface chip)
- 24 pin NEC D449C(A)-1 (2K RAM chip)
- 28 pin HN 612128P (8x16K PROM chip containing program code)
- Large custom JECS chip A10-248 002
- This ECU uses spare socket with MB7132E chip which contains a 1K PROM chip
This ECU also contains Fuel pump circuitry for variable speed fuel pump control.
RB30E Commodore[edit]
- Holden Part # 9203 1690ND
- Main board JECS A19-001-J20 (same as R31 board)
- 40 Pin CPU HD6802 (Motorola 6802 Clone)
- 42 pin IO HD46510P (46510 Interface chip)
- 24 pin NEC D449C(A)-1 (2K RAM chip)
- 28 pin HN 612128P (8x16K PROM chip containing program code)
- Large custom JECS chip A10-248 002
- This ECU uses spare socket which does not contain a chip
- This ECU does not contain components for fuel pump voltage control (missing regulators, capacitors, ICs and some resistors)
RB30ET[edit]
- Commodore VL Turbo Development ECU
- Nissan Motor Company (NMC) Part # 23710-35252 (7)
- Japan Electronic Control Systems (JECS) Part # B18 000 653 (4869)
Knock sensor 6.94KHz
- Main board JECS A19-001 611
- 40 Pin CPU HD6802 (Motorola 6802 Clone)
- 42 pin IO HD46510P (46510 Interface chip)
- 24 pin NEC D449C(A)-1 (2K RAM chip)
- 28 pin socket connecting to daughterboard (Program contained on four separate EPROMs)
- Large custom JECS chip A10-248 002 replaced with Fujitsu MB113T111 (8429 - K13)
This ECU uses spare socket with MB7132E chip which contains a 1K PROM chip
- Daughterboard JECS B19-051 529
- Contains 4 EPROMS 8x8k
- Knock sensor circutry (as in the Z31 ECU)
- 30 pin M59203P - Mitsubishi chip for knock sensing
- 16 pin TDS2501P - Toshiba chip
- 8 pin - NEC - C125 chip
Notes
- Nissan ECU Numbering
- 23710 - Part type (ECU)
- __X - First Nissan model
- __ - Specifcs to the part number
The HD46510P in the Hitachi/JECS ECUs was superceded by the HD63140CP chip in the R32 ECU.We know that this is a universal pulse processor chip and contains Data direction, port data, watch dog timer, A/D data register, I/O assignment register, Interupt enable register 1024 byte SRAM. The code must interact with the registers on this chip to perform A/D and timing operations. The A19 JECS chip is also seen labeled as Fujistu custom number chips which are suspected to complement or perform similar function
Knock sensing in all boards for import vehicles (Hitachi) appear to consist of the same components. The knock must be tuned to the correct frequencies of the engine to function properly