rlord

IPDM question:
Recently completely rebuilt the motor in 03 350z manual. Cranked right up, I mention this because the guy we took it to tune said" people normally just get a new/used engine because it's such a PITA". So remarkably it runs and drives. He cleared some previous error codes, but have the following issues:

Bank 2 camshaft solenoid half or less reading of the Bank 1. 15/36 and went down further as he swapped in two used solenoids from the shop.

A/C will run and cool, fans run. Fans will stop, A/C blows but doesn't cool. Previously had thrown the belt when it A/C disengaged before. Have some cooling issues, found a small leak (fixed), but the car will run, drive, race the gears in the mountains. Interstate driving overheated it. Another instance it drove 1.5 hrs with no issue then, purged the coolant. Overheated because fans suddenly stopped (ghost in the machine) or accumulated an air pocket.

Using his Scanner, it would not read the IPDM at all, which may explain the issue above with the fans? Question: Does the scanner read around the ECU for the others or does it first have to signal through the ECU? So bad path through the ECU issue so it doesn't acknowledge the IPDM.

I found a used IPDM, assuming that's the issue. Can I plug and play that and how do I know if it'll work for the car? It appears identical. I've visually compared and the numbers on the top sticker and it's a D type?

I'm old enough to remember when you only had to check two things for electrical, power to starter and spark? Mechanical stuff is okay, but the electronic stuff is beyond my pay grade apparently. I'll pay to have it fixed if I have to, but would like to see if we can complete the mission.
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karlt

A scan tool can read whatever units are connected to the diagnostic pin on the OBD-II connector, pin 7. For the 2003 Z that includes the ECU, BCM, ABS, Air Bag, and TCM (with auto transmission). The IPDM is not connected to this pin and thus cannot be scanned.

You can, however, perform an operational test of the IPDM. Download the Power Supply section of the Service Manual (https://www.nicoclub.com/nissan-service-manuals) and look on page PG-24.

rlord

Thanks, I'll check that today for sure. Appreciate the page reference. Shouldn't the shop tuning the car know that????? Chasing shadows.

rlord

Are there different level scanners? The thing was supposedly top of the line, read everything in the car, etc type deal. Still went through the same port though.... It's a good Z/G shop, not just a general mechanic.

karlt

Unlike most of the other control units, the IPDM doesn't generate fault codes, so there is nothing for a scan tool to read. That explains why the IPDM is not connected to the OBD-II diagnostic line.

calvin.w

IPDM stands for Intelligent Power Distribution Module. And it is just that, a box that distributes power from the battery to throughout the engine/car. It's not a computer like the ECM or BCM, basically it's just a fancy fuse box
Like stated above, you can check operations on the IPDM (test the power to everything basically)

karlt

Not quite. Like the other control units in the car, the IPDM is controlled by a microprocessor and is interconnected to those other units by the CANbus. In fact, many of the actions taken by the IPDM are driven by data sent over the bus. But it relies on those other units for correct data. The IPDM can be diagnosed over the CANbus with a Nissan CONSULT II or III factory diagnostic tool, but the only fault it will report (at least in my 2005 model) is U1000, a data bus error.

rlord

Thanks. I haven't had time to run the diagnostic test as of yet. Hoping to get that done today.

calvin.w

where were you when I needed help with my ac/IPDM 😑