Electrical issues?

NOTSTEVE

MEMBER
2012 NISSAN MICRA
1.4L
4 CYL
TURBO
2WD
MANUAL
127,000 MILES

Car Issue Summary (Nissan Micra Diesel 2012)

Hi, I need help diagnosing a strange electrical issue with my 2012 Nissan Micra XV Diesel.

Symptoms (only after 40+ mins of driving):

Speedometer suddenly goes crazy, then stops working

Key warning light appears on the dash

Steering becomes light like EPS is off

Car jerks while accelerating/decelerating

Car doesn’t shut off unless I hold the stop/start button for long

One time after bump-starting (without ignition ON), car didn’t start for a few mins

Airbag light is always on

Error code related to rail pressure stored

What I’ve Noticed:

Problem only happens after long drives

No parts like ECM, alternator, or battery have ever been replaced

Idle engine load is ~45%, rail pressure ~220 bar

What I’ve Done:

Checked fuses visually

Checked battery:
Engine Off-12.69v
On-14.25v
On Load like ac, radio, headlights, etc-14.05v

Any ideas on what might be causing this? Could it be ECM, IPDM, grounding issue, or something else?

Thanks in advance!

Wednesday, May 21st, 2025 AT 11:55 AM

3 Replies

KEN L

MASTER CERTIFIED MECHANIC
51,603 POSTS

Hello,

Yes, you are on the right track, I have seen the IPDM cause these kinds of issues but before replacing it I would do a CAN scan, here is video which will show you how:

https://youtu.be/u-4syLc-ifQ

If the IPDM is bad there should be codes giving us confirmation if the issue.

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Thursday, May 22nd, 2025 AT 11:48 AM

NOTSTEVE

MEMBER
2 POSTS

Need Help Diagnosing Electrical Issue - 2012 Nissan Micra XV Diesel

Symptoms:

After 40 minutes of driving, speedometer drops to 0 while driving

Power steering becomes extremely light (no resistance)

Key warning light appears on dash

Car starts jerking during throttle changes

Car won’t turn off unless I hold the stop/start button for a few seconds

Fault Codes (when issue appears):

B2629-00 Vehicle Speed
B2615-00 BCM
C1606-01 - EPS Motor

What I’ve done so far:

Battery, ipdm and alternator checked � working fine

After heating up, the issue returns exactly the same

If cooled down and restarted, all works normally again

Main Question:
Is this more likely to be the Vehicle Speed Sensor (VSS) or the BCM (Body Control Module) failing when hot?
Any tips for diagnosing or testing further?

Thanks!

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Sunday, June 1st, 2025 AT 1:17 PM

KEN L

MASTER CERTIFIED MECHANIC
51,603 POSTS

These codes are the main problems, but I would replace (or have tested) the BCM first in case it fixes the other codes as well. I have also seen the instrument cluster go out and back feed into the BCM as well, did this car have water damage?

B2615-00 BCM
C1606-01 - EPS Motor

Here is the BCM location, also a bad ground car cause this as well, here is a guide to help test the connections and the wiring diagrams as well. Check the fuse again for the BCM as well.

https://www.2carpros.com/articles/how-to-check-wiring

Check out the images (below). Please let us know what happens.

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