# 1987 Hardbody 2.4 manual ECM Trouble



## burts (Feb 25, 2016)

1987 Nissan Hardbody 2.4 Manual 4x4 Nap Z

My cousin bought a refurbished ecm from napa because his truck would not engage the fuel pump. Since then a year ago his truck has what can be described as a governor. Hits a certain rpm and will not go past it in any gear..

His napa receipt is gone and the old computer is gone. I cannot find a oem part number on the refurbished ecm to verify that it is not a automatic transmission computer.

I check ebay and find 2-3 ecm for example and all 3 have a dif part number for the same year, same engine trans leaving me lost to help him...

What is the ecm oem part number for this model in manual trans.

I dont know if he has a defective ecm or a ecm from a automatic transmission...


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## jp2code (Jun 2, 2011)

Do you know how to pull the codes? If the ECM has codes stored in it, the engine can have a hard time running around the 2500 RPM range.

Here is a write-up I did on how to pull and reset the codes:

[VIDEO] Checking Error Codes - Infamous Nissan - Hardbody / Frontier Forums


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## SPEEDO (Jun 9, 2003)

start with jp's suggestion, but here are some numbers..
7/86-3/87 23710-07G01
3/87-7/87 23710-07G04
depending on the production date
for a Z24I, 4wd, mt


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## burts (Feb 25, 2016)

From looking at pictures and from memory his ecm has a on off switch on the left and from online pictures it has two diagnostic recessed slotted knobs.

The vids of pulling codes only show one knob, also whats the switch for

Thank You


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## jp2code (Jun 2, 2011)

The dial turns one way to enable diagnostic mode. Turn the other way to disable.

In the same way, the switch turns one way to enable diagnostic mode. Turn the other way to disable.

The 1987 codes might be different than most. The 1986 had a mix of code values.


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## smj999smj (Jan 1, 2006)

Nissan has both two mode and five mode diagnostic systems. If there is a toggle switch on the side, it is the two mode type ECM. The toggle switch is used to put the ECM into diagnostic mode so that is will display trouble codes. Best source for information is the factory service manual, but a little Google searching should be able to locate information on this procedure. As far as the ECM part number, try going to NissanPartsDeal.com and looking up the engine control module by VIN # and it should give you the part number. 
That all said, it sounds like you are in fail-safe mode, as suggested above, which limits the RPM to 2500, at which point the engine will start surging. If this is the case, there should be a code stored.


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## burts (Feb 25, 2016)

Disconnecting the negative cable should erase the codes right? Yes it is a two mode ecm, the switch displays codes, my friend is getting me another ecm from the same type truck 1987..I do not know why there is 2 dif part numbers for year 87


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## jp2code (Jun 2, 2011)

Nissan changed the codes the ECM used at some point. I think the newer one is ODB.

Disconnecting the Negative cable will erase the codes, but it seems like the Service Manual says it needs to stay off for 15 minutes or so. I'm guessing that means there is a capacitor to prevent losing codes during a power loss.


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## McCarrell62 (Mar 10, 2020)

Can I use an ECM for automatic transmission on a standard transmission?


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## jp2code (Jun 2, 2011)

McCarrell62 said:


> Can I use an ECM for automatic transmission on a standard transmission?


It isn't a direct swap. The automatic transmission has different sensors than the manual transmission. Nissan added more to the newer models than older models had. If you use an automatic transmission ECU, look up what sensors that year model used and find a way to bypass those.


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## smj999smj (Jan 1, 2006)

McCarrell62 said:


> Can I use an ECM for automatic transmission on a standard transmission?


You don't mention what year/engine you have. If it's an 87 with a 2.4L like the OP, the ECM's are different between the manual and automatic transmission. Rockauto has a reman ECM's for $200 for that year/engine at their site for both auto and manual transmissions.


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