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ECU reporting wrong temp, No closed loop
#1
Fixkick,

re: my low engine temp issue...

Is it possible that the ecu is artificially setting the engine temp low to prevent it from going into closed loop mode? If the computer is seeing something wrong with the 02 sensor, is it possible it would artificially pop the wrong data into the ECT variable to prevent a closed loop activation?

I'm going to throw in the new 02 sensor in the next few days and will test some more.

Two of the gurus in the suzuki forum say what you have said, that it's very rare for the ecu to give erroneous engine temp readings. They are stumped as well and telling me to take an IR reading on the engine. I will, but I measured the sensor at the ecu cable and it was seeing around 300 ohms. So, I'm pretty confident the engine is at normal operating temp. Needle in dash is at midpoint too.

I just stumbled on this idea since I was reading about limp home mode how the computer will artificially stick a valid data point into a variable to let you return home. Maybe it's doing the same here? But, where this theory fails is that they could have thrown up a CEL code and it's not. Maybe there is a reason they didn't want to do this?

John
95 Geo Tracker, Build Date 1/95,16v, Fed, Cami, 4x4, MT, Headed for Grenada.
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#2
good morning.
no the ecu can not control engine temps, the RAD + thermostat does that. and is working
the ECU reads the ECT as a voltage, and A/D converters that to binary data. called dac counts.
the ECU sees it as a voltage and then looks it up in a table. for ECT and translates voltage to temperature.
if forget if i did that exercise,???
let me look.
id bet the engine is 180f. and the ECT is 300 ohms (it is) and the dash is at mid scale, (it is) and the ECU is working, and it is reporting 180f but the software. is wrong. (rhinoman software and co.)

the ECU always uses the ECT as verbatim. it only uses fake ECTs reading if IT fails. only.
i cant speak for backup-mode, its not documented on earth.

in limp home the bad sensor is mimicked. simulated in a very very crude way, either a fixed number. or is scaled crudely
say you unplug the MAF.
the ECU then creates a virtual maf, it uses RPM and and the TPS angle as very crude maf, (modeling )
the designer set the model to rich side on purpose. so as not to burn up a good engine.


the rhino scale is wrong, they may have used a wrong plug in table at compile time. id bet this, is it.



i did play with the ETC once.
here is the voltages I read.
http://www.fixkick.com/ECU/temp-sensors.html
and the Ohms law math, there.

my 1996 has a 2000 ohm pull up to 5vdc. (i reverse engineered that fact)
and this allowed me to calc. volts at the ECT side

the FSM does state the 158F critical temp from cold engine mode to warm up mode,

0.6v hot. (meter across ECT) the 92 to 1998 ECT is same p/n sensor, so this voltage it good.


one more fact coming.
how many ECTs were used on engines. G16.? or even G13>
ill look that up easy.
keep in mind he, is in UK . and runs, UK Vitara's that have many forms,(suzuki type codes) all that is can look up easy.
more later

smoking gun
all of ours are 61b00 ECT sensors. on 8v engine and 57F00 on all 16v up to 1998.
UK market code E02.
the UK engines are called type/2/3 for 16v and uses the same sensor.
type 1 engines there use 61b00 or ever other odd sensors.

so you need the the software for UK Suzuki SE416 (vitara code) Type 2 or 3 engines. or SF310 or SF413(swifts)
Im not sure who to contact but id join there forum and ask for type 2/3 software for ECT.
http://www.fixkick.com
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#3
see parameter 09, command.
this is far as i got with that.
does your Rhinosoft have a hex mode like my 0bd2 scanner, from Palmer, does.??? a real cool feature that and for debugging. (shows true values, not scaled yet)

http://www.fixkick.com/hacking/hacked/ad...acked.html



a9, hex is 169 decimal
i do not know at all, how the ECU scales this this raw data. here. but was told , the software must use a table.
http://www.fixkick.com
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#4
fixkick,

I received fantastic news today! Rhinoman is engaged with my data issues. He found that in later years GM started cutting in some ODB2 stuff and may have caused an issue with the readings I have. He said the CTS is wrong and the 02 activation is not working. He's going to work on it and release a new version with the fixes. I'll be able to do more testing when he has an update available.

So, it appears my engine maybe running fine. I'm going to continue with the complete service and set the timing when I'm done. I'm happy I don't have an issue!!

I appreciate you hanging in there with me on this one!!

John
95 Geo Tracker, Build Date 1/95,16v, Fed, Cami, 4x4, MT, Headed for Grenada.
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#5
You are welcome, !
http://www.fixkick.com
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#6
if you are in touch w/ him.. see when the new cables will be available!!!!!
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#7
the 95 and 96 have same engine, and the CTS (ECT) are same part numbers, USA. -57F00
and are identical to UK type 2/3 16v engine, same part numbers. (so same resistance/temp)

what i suspect is they are using tables for some old UK type 1 engines. that may be different. 61b00 ECTs' may be different.
suzuki makes 56 engines,so can be daunting.
http://www.fixkick.com
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#8
Speaking of similar engines. When I go to the suzuki parts pages, some of them do not list trackers. Only samarai and suzuki. Is there a model of those cars that is identical to a tracker from an engine perspective? I want to order valve cover gaskets etc. Or, is it better to get them through a local napa?
95 Geo Tracker, Build Date 1/95,16v, Fed, Cami, 4x4, MT, Headed for Grenada.
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#9
suzuki sidekick = geo tracker = chevrolet tracker = pontiac sunrunner = chevrolet vitara = suzuki vitara = suzuki escudo

I'm sure I'm missing some.
1996 Geo Tracker, CAMI, 16 valve, 5sp, 4x4, soft top, 2 door, no a/c
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#10
for engine parts. just know what engine you have, the Suzuki uses engine code 0 (vin) for both engines.
and in USA, only 2 cars, 95, suzuki and tracker) up in Canada they have sunrunners and even black market Vitaras in 1995
you can buy lots of parts on local store, do so.
in fact 99.9% counterfeit free, unlike feabay junk and not 3 way china clone rotors. none.
Napa or Advanced auto are too top names, i never every buy autozoned parts durajunk. but do by rags there...

if ordering from afar, say Grenada? use rockauto.or suz, dealer. (email them first)
or even amazon if they will ship out of country.
many stores will not ship out of mainland here.
i buy parts by name, say bosch or ngk or say Felpro fine gaskets then google search for exact pn/ and find fabulous deals.. (if timing is not important) sure.
all catalogs are online now. all above and SMP.

most the cats get the engines right, clearly shows it , unlike most stores.

your car is a VIN 6 tracker.
that is GM code for 16valves.
good stores know that.
http://www.fixkick.com
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