I have an intermitent issue where the electric fan kicks in and i get check engine light. Car then runs badly. Fanalo come son just with ignition on an and not with engine running. I have taken off temp sensor and cleaned it up and car runs ok but problem does return eventually. Have used a connector cleaner this morning and it doesn't come onon ignition. To check it i disconnected temp sensor and put ignition on and the fan doesn't kick in.... so now i have no idea what's going on !

 

Any idea ?

The only cause of engine light to come on with engine running is an ecu fault, either corrupted eprom or maybe a badly fitted ( soldered ) chip socket, this will also bring the fan on too.

 

 

Jeff TT

Thanks Jeff. I will run another ECU check. Last time it was all clear even though check light and fan came on.

Thanks Jeff. I will run another ECU check. Last time it was all clear even though check light and fan came on.

 

What you need to do is actually take the lid off and take a look around the chip area to see if there is any poor soldering (if its been socketed /chipped) or any burn marks anywhere.

 

A common cause of damage to the ecu is injector cables shorting out as they stay live even with the ignition off. ( done any work on the injectors lately?)

 

Have you have the ecu upgraded in the past or was it done to your knowledge prior to you buying the car.

 

Jeff TT

Have done an ECU check this morning and get code 13 - coolant temp sensor circuit. Guess this ties in with the intermittent kicking in of the fan. The conneshould ctor looks worse for wear and corroded so that appears the obvious thing but i check anything else before i get a new temp sensor and conector? Cant get a reading off the left o2 sensor either. Time for some TLC I think.

Have done an ECU check this morning and get code 13 - coolant temp sensor circuit. Guess this ties in with the intermittent kicking in of the fan. The conneshould ctor looks worse for wear and corroded so that appears the obvious thing but i check anything else before i get a new temp sensor and conector? Cant get a reading off the left o2 sensor either. Time for some TLC I think.

 

If you find you cannot sort the issue out you could always send us your ecu and can do a bench test on it for you on our emulator, no charge for that, could save you some time.

 

Jeff TT

Are you sure its not just air lock where temp sensor is,this has happened to me twice.

new temp sensor and connector arrived. I assume this is a simple unscrew the old, install the new, splice new connector on and plug in?! oh and keep fingers crossed and pray to the Zed gods this is the answer :-)

new temp sensor and connector arrived. I assume this is a simple unscrew the old, install the new, splice new connector on and plug in?! oh and keep fingers crossed and pray to the Zed gods this is the answer :-)

 

Yep that's it!

Good luck ;)

smithy

new temp sensor and connector arrived. I assume this is a simple unscrew the old, install the new, splice new connector on and plug in?! oh and keep fingers crossed and pray to the Zed gods this is the answer :-)

 

The only cause of engine light to come on with engine running is an ecu fault :cry:

 

Jeff TT

Thanks Jeff...kind of!

 

started up this morning without fan on or engine check light but idle was lumpy and not normal at all. Decided to take ECU out and checked it, no visible circuit damage at all. reconnected it and ran diagnostic and got 55 ( no errors) however still idled badly. Turned off and on again and fan kicked in again :-( So decided to replace temp sensor and connector and this looks like its done the Job as Idle back to nice and smooth and driving fine again if not better than before. Just about to clear up and go for a decent run as its dry and sunny. Fingers crossed!

Right, all seemed well, then hit a bit of bump and engine check light and light and fan came on again!!!! Turned car off and on again and still on, tapped ECU in desperation and light went off and fan stopped, drove car back home and all is fine- still better since temp sensor changed. ECU code still shows code 55 - no errors. Perhaps an intermittent ECU fault ??? cant see any loose connections. Anything else i should check ?

You didn't tighten the screw on the ecu connector too tight did ya? that can cause the connector to bend a bit, sounds like that may be a potential culprit, i had it on mine, but was causing mine to miss.... Have a fiddle with it... HTH.

The only cause of engine light to come on with engine running is an ecu fault

Jeff TT

 

Are you sure JeffTT;)

Im not sure JeffTT,as i said my engine light came on,aux fan and tickover went up and it wasnt ecu fault.

Are you sure JeffTT;)

 

Yes, the diagnostic system OBC1 is limited in its fault reporting and has no facility to illuminate the engine management light when the engine is running, unlike OBC2 which has this built in, if the engine management light come on when running its either a corrupted chip or an loose/ dodgy soldered connection under the eprom.

 

Jeff

Im not sure JeffTT,as i said my engine light came on,aux fan and tickover went up and it wasnt ecu fault.

 

As mentioned above the ecu has no faciolity to illiminate the engine management light when the engine is running, so if your was on and now its not, it just means the connection has at this time is ok.

 

Jeff TT

I have to admit that the way it's behaved does make me think its a dodgy connection somwhere. Seemed all fine then as car had a bit of jolt it went wrong again and after a bit of amateur fiddling it was ok again. Still ran better after temp sensor changed so that clearly needed doing. Just need to check connections again when I have time.

 

Where's the eprom?

Inside the ECU mate, I'll see if i can find ya a pic.....

Here ya go mate, it's the rectangular chip, bottom left, i would have circled it for ya, but got no paint type drawing effort programs on this lappy...... HTH...

 

P.S. your's could look slightly different, (stickers on it, etc.) although it will be the same size and dimensions, and in the same place, if it has been changed, re-mapped etc.......

Thanks Tudor...will take a look at it and see what I can see!

Now this is odd! The eprom chip says Mitsubishi on it!!! not sure how i missed that at the weekend:wack: and then looks as though someone has written Z32 Auto on it in pen! Had a look underneath this time and the solder underneath the chip also appears to have broken down on a number of connections. This leads me to the conclusion that the car has been chipped while it was in Japan as I bought the car as a fresh import 6 years ago. I always thought it seemed a bit more lively than standard ( had UK manual years ago and it's also pokier than the 350Z I just got rid of!) seems to answer the question.

 

Also leads me to conlude Jeff is again correcto ! :bow:

 

Jeff can I take you up on the offer of me sending you the ECU to plug into your emulator? Can get it sent special delivery tomorow. Hopefully we can get this sorted in time for me to come and eat your Pork Cobs!:rolleyes:

Yes, the diagnostic system OBC1 is limited in its fault reporting and has no facility to illuminate the engine management light when the engine is running, unlike OBC2 which has this built in, if the engine management light come on when running its either a corrupted chip or an loose/ dodgy soldered connection under the eprom.

Cheers JeffTT

Jeff can I take you up on the offer of me sending you the ECU to plug into your emulator? Can get it sent special delivery tomorow. Hopefully we can get this sorted in time for me to come and eat your Pork Cobs!

 

Of course, send away will deal with it for you asap.

 

Jeff

Ecu just arrived been tested now.

 

Jeff

Jeff, new ECU arrived and plugged in, I now have a happy Z again! Quite a lively little unit the new one! Thanks for your prompt help.