Just behind the fan there's a silver pipe that runs lengthways. It houses the temparature sensors for the dashboard, the ecu, and there's a third. The first two are on the same mount (yellow block with a black and a yellow/green wire). It's the third sensor, and blue-headed wire on its own, just to the right of the double-headed one.

 

Can anyone please tell me what this third sensor is for, and a part number if you know it - I'm getting code 13 from the ECU, have replaced the yellow-block sensor, but am having same problem...

 

Thanks a lot...

Any chance of a digital pic? I've only got two temp sensors on mine!

 

Cheers m8

Simon.

Drew can not say about a third sensor? but you code fault is defo the coolant temp sensor should be the left hand yellow one (bigger of the two)

If this fails or connection is dodgy the front air con fan normally runs when ignition on.

Jeff TT

Some confusion here.....

 

There are only TWO sensors on the top pipe! One of them has a two pin connector the other has a single pin connector. The two pin sensor is the one for the ecu. The second sensor with the single pin is for the temperature guage on the dashboard - this only has one pin as it uses the engines earth(ground, -ve) as the second wire. The two pin sensor has its own earth wire AFAIK and is why it has two connections

 

If the ecu is still giving the error code after the sensor replacement then this would suggest that there is a break in the wire somewhere between the connector and the ECU. Check inside the connector also for and green deposits which are corrrosion and will stop the sensor working. Also check that the ECU connector is pushed in and seated properly.

 

CheerZ,

 

Andy

Thanks for the replies.

 

It appears that I've done the following:

 

1) Mistakenly disconnected the single wire (blue-topped, on RHS) - as the temp readout on the dashboard is now disabled. So I'll be replacing that...

 

2) Of the two wires that go into the other connector (yellow block), I've only reattached the yellow/green wire - have left the other one disconnected (as I thought it was the dashboard sensor).

 

Consequently, I am currently experiencing the same problem: car starts fine when cold, but cuts-out when engine heats up. As I've replaced the twin-headed sensor, are we thinking that re-connecting the second wire should remedy the problem???

 

Many thanks for your help with this matter.

 

Drew

Drew, connecting that other wire should cure the problem. If not just let us know....

 

CheerZ,

 

Andy

Have rewired the 3 wires so all now correctly connected. Unfortunately, same problem remains.

 

The fan stays on when ignition is on and when car is running: is that correct? The mechanic who's been looking at the car now thinks we should do a 'continuity check' (making sure that the wires aren't losing their conductivity somewhere along the line?). Do you agree this should be the next check?

 

Thanks

 

Drew

if the front electric fan stays on, then yes, there is a problem with the ecu coolant sensor signal.

 

continuity check sounds like the next step, yes.

I've been asked to check a couple of things with you before doing the 'Continuity Check':

 

Which plug and which wire numbers on the ECU should we be testing? Also, is the wire the same colour at the ecu (i.e. green and yellow)?

 

Thanks a lot

 

Drew

Drew - the wires are indeed the same colour when they get to the ecu The pins you need are 28 for the black and pin 30 for the yellow/green. To find out which these are there is a picture of the plug on the first page of the wiring diagram section of the online manual here http://www.300zx.co.uk/cgi-bin/manual.cgi

 

CheerZ,

 

Andy

That's great! Thanks a lot.

My car's still off the road :-(

 

I've changed the Temp Sensor itself (got a 2nd hand one), have made sure the connections are all clean, have done a continuity test, have bought a new battery (!), and now the car won't start at all!!!

 

The ECU's still giving a Code13 readout. Don't know what to do, getting close to insanity...!!!

 

Any more advise gratefully accepted...

Hey drew

 

when you said the battery is now dead does that mean it had enough time for the ECU to reset?? i mean more than an hour?(to be on the safe side)

 

if not then try and reset the ECU. what was the result of the continuity test?

 

Check that the coolant temp sensor wire for the ecu isnt trapped anywhere. also try and mowe it around a bit further down the line to make sure it isnt arcing out against anything else

 

Latz

 

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