Wiking

I ask Greeny to integrate posts of this issue from rmd's tranny thread.

The Maxima FSM technical Writer never understood what she was writing and/or illustrating. She tried her best ... ?

One of the issues is the unnecessary mystification of sensors: The temperature 'sensors' are just variable resistors. No mystery between JDM etc 'engines' ... or one/two wire connections. All work in the very same principal: current flow is enhanced depending on R-value. ECU detects the variance.

The resistance has to fit designed ECU input... and here is no mystics but just need for a reliable info what the ECU input is designed for. Routing a new single wire from a resistor to dedicated ECU input is easiest job in the world. ECU pins have all been documented... The possible second wire will be just grounded, old temp related wiring just cut off.

The reliable cross reference table to all ECU's would take this mystery out - I hope some knowledge will be collected here.

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To Confuze us, at least these Temperature -related names can be found in the FSM - pls add to the list:
- Thermal Transmitter (transmitter!!!)
- Engine Coolant Temperature Sensor
- Engine Coolant Temperature Sensor ECTS
- EGR Temperature Sensor ---> FOR COOLANT
- EGR Temperature Sensor ---> same name FOR EXHAUST GASES
- Water Temp

This is why the issues has as many opinions as there are nations penetrated by maximas... Also there may be some differences with the VE30DE engine (I wont go there b/c I cannot inspect such vehicle at the moment, but feel free to add any info - with engine type). I am determined to dig here in all info the -94 FSM represents -and- what I have at hand.

I will also update/edit my EGR/Temp Sensor -page accordingly:
http://www.cardomain.com/ride/748507/3

First some FSM etc pics, be they right or wrong - pls yall ppl give opinions:

PIC1 - from my VGE.

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This pic below is clearly demonstrating EGR to Coolant measurement. The range at least is for water ... right?
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PIC2 - Haynes.

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PIC3. - Haynes - at FSM page EF&EC-143 this resistance value is (falsely?) given for the yellow two pin sensor called [Engine Coolant Temperature Sensor]

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PIC4. - FSM


PIC5. - FSM EF&EC-145

Wiking

Continued...
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PIC 6 - Modded from FSM to fit VGE. EGR ctrl via coolant temp?

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PIC 7 - FSM

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PIC 8 - FSM - Enhanced gauge & sender unit LOL transmitter

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PIC 9 - FSM


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Then the last mystery where FSM has no other support: Exhaust Temp Sensor... Note: ALL OTHER do relate to coolant temp.

Even the EGR System Description has absolutely no mention of exhaust temp measurement - see EF&EC-23.
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PIC 10 - FSM

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internetautomar

iTrader: (30)

EGR temp sensor is not coolant related. it is detecting the temperature of the exhaust gases by the valve.
the Exhaust temperature sensor measures the temperature of the exhaust, it was used on california emission spec models.
There is a coolant temperature sensor which feeds the temperature to the computer
there is a coolant temperature sender which sends the temperature to the gauge.

Wiking

FSM clearly (?eh) tells the EGR-coolant story ...

This is true - isnt it?

1. TWO coolant temp sensors:
a. one single wire just only for dash gauge,
b. 2-pin yellow plug, 2-wire, to ECU.

2. NO EGR coolant temp sensors, never, none. FSM is here bs...

3. EGR exhaust temp sensor just in California models.

CapedCadaver

iTrader: (8)

the temp sensor is possibly in all models just not connected. as a cost-saving measure. Wiking do you have the sensor sticking out of your EGR hose that i took a picture of yesterday?

CapedCadaver

iTrader: (8)

oops i uploaded them but never posted a link on the ORG.
http://s164.photobucket.com/albums/u...temp%20sensor/
this is the actual sensor:

Wiking

I guess its like this...

LvR

Since I don't have EGR here in South Africa, I obviously don't have an EGR temp sensor either, but in engineering terms that EGR temp sensor will have to be a thermocouple in order to be able to handle the exhaust gas temps and not NTC RTDs as used for the ECTS and guage - as such omitting a thermocouple from the EGR assembly will definitely add quite a saving to the production cost

Wiking

I guess the EGR exhaust temp sensor cost for factory is around 2$, total, assembled, maybe 5$. But with half million vehicles thats a lot for a give away. Like MAF, its factory unit price has to be below ten dollars... but spare price seven (?) hundred. That is called business...

CapedCadaver

iTrader: (8)

that makes me think... does my parts car have one? I haven't ever checked. My DD has a 92+ engine whereas my parts car has the original 89 motor. So I ought to look at that engine before passing any further judgements. I know the harness should be on your car... because that really would save on costs to just make all the harnesses with the plug. instead of picking and choosing and wasting incremental amounts of time making sure the cars had the proper harnesses.