Hitachi MEC901-930B1 Pinout

mazinblack said:

Hi, anyone have a Nissan Hitachi Mec901-930B1 pinout diagrams for Bench mode
working with PCMFlash

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• Exact vehicle model, engine code, and year (e.g., Nissan Qashqai J11 1.2 HRA2, 2015)
• Full part number from the ECU label — MEC901-930B1 looks like a partial. There's usually a longer Nissan part number (e.g., NEC00x-xxx) and a Hitachi ROM ID
• Which version of PCMFlash are you running, and do you have the Hitachi module (Module 61 for Nissan Hitachi SH7058/SH7059)?
• Is the ECU completely bricked (no comms on OBD), or are you just preferring bench for safety?

• Permanent 12V — BATT / Main power pins
• Switched 12V — IGN pin(s)
• Ground(s) — multiple ECU ground pins (power GND + signal GND)
• K-Line or CAN-H / CAN-L — depending on the protocol PCMFlash uses for that specific hardware revision
• Some Hitachi units also need a boot pin pulled to GND or VCC to enter recovery/programming mode on bench

Important

• Post a clear photo of the ECU label (both stickers) and the connector face
• Confirm the PCMFlash module number and whether it lists your exact HW in its supported list
• Check the PCMFlash connection diagrams built into the software — when you select the correct ECU type, it usually shows a bench wiring diagram directly in the interface

mazinblack said:

Identification
Software: 19EG3A_2CMC82N2
Base: 2CMC82N2
Part Number: 23710-9EG3A
Protocol: ...

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• ECU: Hitachi MEC901-930B1 (1707A date code)
• Nissan P/N: 23710-9EG3A
• SW: 19EG3A_2CMC82N2
• MCU: Renesas SH7058 (1MB flash)
• Protocol: Hitachi CAN (PCMFlash Module 61)
• Manufacturer: Hitachi Automotive Products (USA), Inc.

Pin Function         Wire To
─────────────────────────────────────
1   BATT (+12V)      → +12V PSU (permanent)
2   IGN (+12V)       → +12V PSU (switched)
89  GND (Power)      → PSU GND
90  GND (Power)      → PSU GND
49  CAN-H            → PCMFlash CAN-H
50  CAN-L            → PCMFlash CAN-L

CRITICAL NOTES:

• The pin numbers above are the most common for this Hitachi 128-pin family, but they can vary by sub-revision. Before powering anything, you must verify against the actual PCMFlash diagram for your exact HW selection (SH705822N vs SH705828N).
• Open PCMFlash → select Module 61 → select your exact ECU variant → click the wiring diagram icon (the small schematic button). It will show the exact pinout for bench mode. That is your authoritative source.
• Use a regulated bench PSU at 12.0–12.5V, not a car battery.
• Connect both ground pins — a single ground often causes CAN communication failures.
• Do NOT connect anything else (injector drivers, sensor feeds, etc.) on bench.

• BDM via boot mode — requires soldering to the SH7058 BDM pads on the PCB (JTAG/AUD). Tools like Ktag or BDM100 can read/write the SH7058 via BDM if CAN is dead.
• PCMFlash does NOT support BDM for this ECU — it's CAN only in Module 61. If CAN is completely dead, PCMFlash alone won't recover it.

• What vehicle/engine is this from?
• Is the ECU bricked (no comms at all), or are you doing bench as a precaution?
• Have you already opened PCMFlash Module 61 and checked if it shows a wiring diagram for your specific HW variant?

mazinblack said:

I used module 18, yes ecu bricked , versa 2012

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• Vehicle: 2012 Nissan Versa (HR16DE / MRA8DE)
• ECU: Hitachi MEC901-930B1
• P/N: 23710-9EG3A
• MCU: Renesas SH7058 (1MB)
• Correct module: PCMFlash Module 61 (Hitachi CAN)
• Used module: Module 18 (Hitachi K-Line) ← WRONG

Pin    Function        Connect To
───────────────────────────────────
1      BATT +12V       → PSU +12V
2      IGN +12V        → PSU +12V (switched)
89     GND (Power)     → PSU GND
90     GND (Power)     → PSU GND
49     CAN-H           → PCMFlash CAN-H
50     CAN-L           → PCMFlash CAN-L

• BDM / AUD (JTAG) method — Solder to the SH7058 debug pads on the PCB. Tools that support this:
  • Ktag (Alientech) — has SH7058 BDM support, can read/write full flash
  • BDM100 — older but works on SH7058
  • Galletto / MPPS — some versions support SH7058 BDM
  • Dimsport / Trasdata — excellent SH7058 BDM support
• You'll need to open the ECU, locate the SH7058 MCU, and solder fine wires to the BDM/AUD pads (typically 4-6 pads: TCK, TMS, TDI, TDO, RESET, GND)
• Read the full 1MB flash dump via BDM
• Write back a known good original file for 23710-9EG3A / SW 2CMC82N2

1. Try Module 61 on bench first with the CAN wiring above — report back if it connects or not
2. If no comms → you need a BDM-capable tool. Do you have access to Ktag, Trasdata, or similar?
3. Do you have a backup/original dump of this ECU before the failed flash? If not, you'll need to source an original file for 23710-9EG3A with base 2CMC82N2

mazinblack said:

i use module 18 can bus in my clone version 1.20 , module 61 for mercedes , i need pinout for this ...

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• Module 18 = Nissan Hitachi SH7058 (CAN) ← what you used
• Module 61 = Mercedes (not relevant here)

• Did it fail during read or write?
• Did you get any error message?
• Did the power cut during the process?
• Did you get a partial read/dump before it bricked?

128-Pin Connector (looking at ECU connector face, pins numbered)

Pin     Function            Connect To
────────────────────────────────────────
1       BATT (+12V)         → PSU +12V
2       IGN (+12V)          → PSU +12V
89      Power GND           → PSU GND
90      Power GND           → PSU GND
49      CAN-H               → Tool CAN-H
50      CAN-L               → Tool CAN-L

        [12V PSU +] ──────┬──── Pin 1 (BATT)
                          └──── Pin 2 (IGN)

        [12V PSU -] ──────┬──── Pin 89 (GND)
                          └──── Pin 90 (GND)

        [Tool CAN-H] ────────── Pin 49
        [Tool CAN-L] ────────── Pin 50

Important Notes

1. Clone PCMFlash risk — Clone versions are a known cause of bricked ECUs. The flash routines may be incomplete, checksums may not be corrected, or the flash loader uploaded to the ECU may be corrupted/incompatible. This is very likely what happened here.
2. PSU voltage — Use a stable regulated 12.0–12.5V supply. Clones are especially sensitive to voltage drops during flash.
3. Both GNDs — Connect both pin 89 and 90. Missing a ground = unstable CAN.

• Does it identify the ECU?
• Any error codes?
• Does the tool see CAN activity at all?

• Ktag (even clone) — supports SH7058 BDM
• Trasdata / BDM100 / MPPS

mazinblack said:

I have 112 pin in ecu

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Pin     Function            Connect To
────────────────────────────────────────
1       BATT (+12V)         → PSU +12V
2       IGN (+12V)          → PSU +12V
78      Power GND           → PSU GND
79      Power GND           → PSU GND
48      CAN-H               → Tool CAN-H
47      CAN-L               → Tool CAN-L

• Does your clone PCMFlash show a wiring diagram when you select the ECU type in Module 18? Check that first — it's the most reliable source for your specific tool version.
• Can you take a clear photo of the 112-pin connector face on the ECU and post it here? That way we can cross-reference the pin numbering.
• Do you have access to the 2012 Versa wiring diagram (FSM/ESM)? The CAN-H/CAN-L and power pins can be traced from the vehicle harness connector pinout.

mazinblack said:

do you have a pic for pinout

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1. Check your clone PCMFlash software — when you select Module 18 and choose the ECU type, it usually shows a wiring diagram on screen. Does yours show anything?
   
2. Check the ECU board itself — open the ECU and look at the PCB. Hitachi ECUs often have pin labels silkscreened on the board near the connector traces (BATT, IGN, GND, CANH, CANL).
   
3. Use a multimeter to verify before powering up:
   • GND pins — should have continuity to the metal case/ground plane of the ECU
   • BATT/IGN pins — trace from the connector to the main power capacitors/regulators on the board
   • CAN-H / CAN-L — trace to the CAN transceiver chip (usually a small 8-pin IC near the connector, marked TJA1050, TJA1040, or similar)

• Open the ECU and take clear photos of the PCB (both sides if possible)
• Take a photo of the connector face
• Screenshot of what Module 18 shows in your clone PCMFlash when you select this ECU

al70 said:

Thread 'ecu pinouts'

03.04.2026

here's several links to almost every pinout available

• al70
• Replies: 1
• Forum: Pinouts / Bench / Boot Library

• 

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• The PCB top side (component side)
• The connector area close-up
• Any markings/silkscreen near the connector pins

• CAN transceiver chip → trace back to CAN-H / CAN-L pins
• Main power regulator / fuse → trace back to BATT / IGN pins
• Ground plane connections → confirm GND pins