Hcr32 Electrical Issue - No Power To Ecu

[murrayis]

Hi Guys,

Finally have some time to plug everything back in - which for the most part I have done.

I've just gone to turn the key to check power and all sensors are reading however I have limited power to the ECU harness.

Where should I start looking? Which part of the engine harness does the power connect in?

Checking the Power pins on the ECU plug there is nothing... So I assume its a relay or similar?

I've checked the white plugs next to the main ecu plug and there is a couple of pings with 12v however nothing through to the ecu.

Help - TIA

[murrayis]

I've check pins 16 and 45 as per this document for Adaptronics (I'm on Haltech but the same) and I get 0 on both no matter what condition.

http://www.adaptronic.com.au/forum/index.php?topic=4953.0;wap2

[iruvyouskyrine]

Does the haltech use the standard Engine wiring harness?

[murrayis]

Hi

Yes plug anf play. Ive checked all fuses on the car and immobilisers and they are all fine.

[iruvyouskyrine]

The power is fed from a plug next to the washer bottle. It's a big rectangle 8 pin (?) plug and the the two biggest gauge cable is your positive and negative. From memory the white wore with purple trace is positive and black with red trace is negative.

Turn your ignition on and prob these pins for power. They are the single ECU power supply.

[jiffo]

Also check the two green coloured relays beside the ecu.

One is the ecu relay, the other the IGN coils relay.

[murrayis]

I'll replace both these relays asap. Nissan want $70 each for them or japan nissan for $22 each so it might take a week to get them.

I'll check that plug also.

[jiffo]

No need to replace them, swap them with another from the fuse box as a test.

Very rare for either of them to fail so you need to test everything related to power into the ecu.

Only one of those is your ecu power, the other is the coils. You're looking for ecu power.

[murrayis]

Engine bay switch box or under dash?

I did notice there was relay in the under dash fuse area. - Is it spare?

[Duncan]

I've had similar trouble before with PFC on a series 2 33 gtst and on a custom wired 32 gtst just on the weekend. There are wiring differences in ECU power between different models and I'm not convinced the various "plug in" ECUs handle it correctly.

It will vary by car and loom, but on 32GTR for instance, ECU power is pins 49 and 59. Battery 12v goes to 58. When the ECU wants to turn itself on (or more importantly off) it earths pin 16 which turns on the ECCS relay which in turn gives 12v to 49 and 59.

So I would start with checking if you have no power at pins 49 and 59 with the ECU plugged in and ignition on. In both the cars I mentioned above it the ECCS relay was either absent or not wired in, which meant 12v was not being supplied to those pins which the PFC relies on.

[murrayis]

Ok so I checked the relays and they seem fine. I however found the plug pictured above floating at the end of the harness near the LHD headlight, If this the correct plug?

\

I checked and it does have 12v with ignition on - So where does it go? I cannot find a corresponding receptacle :s

[Duncan]

that's the very last plug on the ecu loom.....so go back to the firewall near the ECU and you'll see where that loom comes through, follow it forward past ABS connectors, 02 sensors, AFM and then that plug will be next

[murrayis]

I think I found it.

[jiffo]

That would be the problem.