Oil temp measuring

[JeepsAndGuns]

Ok, showing my noobness. I see this mentioned on this site a lot but have no idea what it means.
What is "A/D" Like you speak of just above.

[RobertISaar]

analog to digital:

it's how the PCM interprets sensors. long story shorter, the ECM reads a 0-5V sensor and then converts it into binary format so that it can know what a certain sensor is doing for all of it's various purposes.

[EagleMark]

Where's the 0 to 255 come in?

[RobertISaar]

well, the A/D system in these ECMs are 0-5 volt 8-bit converters. 0 volts means 0 A/D counts. 5 volts means 255 counts. each count is 0.01953125 volts. notice 255 * 0.01953125 = 4.98volts. can't express decimal 256 in 8 bit numbering.

if it was a 10-bit system(like the autoPROM has), then it would be 0 to 1023 counts. assuming a 5 volt system, each count is 0.0048875855327468230694037145650049 volts.

notice, it's 2 to the nth power minus 1. 2 being that there are only two states (binary 1 and 0), and N being the bit resolution. 2^8 = 256, then subtract 1 due to not being able to express $100(decimal 256) in 8 bit format, and you have the 0-255 range.



now, once you get that figured out, think about the other analog inputs that are used by the ECM that aren't 5 volts... O2 sensor is 0-roughly 1.127 volts over a 0-255 range. and then you have ignition and fuel pump voltage available in a 0-25.5 volt range.... to read over 5 volts with a 5 volt A/D converter, you need to make a voltage divider network. let's say we have a 0-10 volt sensor, since it's easy to calculate. we make a voltage divider with the sensor signal going through a resistor (let's say a 1K, since it's a common unit), then on the other side of this 1K resistor, there is another 1K resistor, this one connected to ground. now, the A/D channel will be connected between the two resistors(since before the first will still be 10 volts and after the second will be ground), and that will allow a 0-10V sensor to be read using a 0-5V A/D unit.

the O2 sensor.... well, that's why the O2 sensor amplifier is there. i'm not entirely certain how it works, but from what i understand, it simply takes the 0-1.127 volt signal and multiplies the voltage by a factor of ~4.43, and at that point, it outputs a signal for the A/D system to read.

[JeepsAndGuns]

Umm, so in laymans terms, its just a lot of un used possiable sensor inputs?

[RobertISaar]

depending on the mask you want to run, yes. certain ones only want to see the basic coolant temp, IAT, TPS, MAP and maybe a couple of others...

some want those + trans temp, oil temp, a/c pressure, etc, etc....



keep in mind, that was a description only for the analog inputs, there are also discrete inputs, which are a little less confusing to explain, those are basically switches.

[EagleMark]

Umm, so in laymans terms, its just a lot of un used possiable sensor inputs?

well, the A/D system in these ECMs are 0-5 volt 8-bit converters. 0 volts means 0 A/D counts. 5 volts means 255 counts. each count is 0.01953125 volts. notice 255 * 0.01953125 = 4.98volts. can't express decimal 256 in 8 bit numbering.

if it was a 10-bit system(like the autoPROM has), then it would be 0 to 1023 counts. assuming a 5 volt system, each count is 0.0048875855327468230694037145650049 volts.

notice, it's 2 to the nth power minus 1. 2 being that there are only two states (binary 1 and 0), and N being the bit resolution. 2^8 = 256, then subtract 1 due to not being able to express $100(decimal 256) in 8 bit format, and you have the 0-255 range.

I think he said 0 to 5.0 volts is divided by 256 counts, expressed as 0 to 255 because computers count from 0.

Haven't tried to figure out the other one yet...

[RobertISaar]

correct, Mark.

[EagleMark]

woo hoo, I'm up to Geek...

Long way to catch up to uber nerd...

[dyeager535]

Does anyone happen to know the specs on that sender Mark turned down and rethreaded?

Real question is if they will work with the older GM gauges and ECM's? 0-90 ohms I believe is the resistance specs for the fuel, coolant temp, and oil pressure gauges, at least on my 80's truck stuff. I would prefer not to have more parts laying around I can't use. I have a whole box of new Delco parts I bought on ebay for just a couple pieces. I probably should dig it out to see if I have this sensor in there already!

How about the connector part #? I had no luck finding the pigtail. I found the year interchange for this sender (mostly 3.1 and 3.8's for a wide range of years) but could find no connectors. Normally I say wrecking yards, I've yet to find reasonably priced pre-made connectors. I've seen the connectors with wiring ends go for more than the sensor itself.

Somewhere (LS1.com?) I found a post where someone retrofit an LS1 into a 1968 vette and had some problems with the coolant sensor not working with the stock gauge, which is what led me to question the resistance values. It seems odd they didn't use it in more applications. Then again it may cover all the 3.1/3.8's, which was a fairly large swath of vehicles.

[EagleMark]

This site has a ton of pigtails but not real cheap, here's the three terminal oil temp plug and pigtail which may be same as coolant temp?
http://www.eficonnection.com/eficonn...spx?ItemId=814

mouser is cheapest but be prepared to spend hours looking.

If I don't have good plugs from all the harness that I have I do a Pick and Save trip and come home with a box full...

Don't know about gauges?

[dyeager535]

Here's the Echlin catalog I couldn't find before for some reason: http://www.napaechlin.com/upload/NAP..._NA141_HQr.pdf

Cross the part number referenced before, comes up with Echlin PN TS4020, which on page 991 states "2752Ω @77°F w/20% Tol between terminal 1& 2, 2464Ω @77°F w/20% Tol on terminal 3, 3/8 x 18.

Stock CTS for an '88 Camaro TS4052 2 circuit pins N/C – 2786Ω @77°F 3/8 x 18 NPT

Stock guage sender for the truck is 2155–2771Ω @77°F, C@100°F 1425Ω w/7% Tol, O@220°F 147Ω w/15% Tol 3/8 x 18 NPTF

Open/closed should be meaningless, it's a sender, not a switch.

Does it appear to others that the ECM portion and the gauge portions of TS4020 will work for retrofit?

[phonedawgz]

For what it's worth. The standard GM gauge thermistor uses a different profile (look up) vs the standard GM ECT. This is the GM gauge thermistor profile.

faq-temp_gauge_vs_resistance_chart.jpg

[dyeager535]

So can anyone answer why the gauge sender specs are WAY off what that chart shows? Supposedly the one I reference above is for my truck, which is using 80's style gauges.

Not going to keep replying, will just add/edit info here. AC Delco part number for three wire CTS in this thread is 213-815. Applications for fellow junk yard scroungers (taken from the ACD site):
BUICK(45)1994-2002

CENTURY(10)1994-2002

2002 V6-189ci 3.1L F/I Vin J

2001 V6-189ci 3.1L F/I Vin J

2000 V6-189ci 3.1L F/I Vin J

1999 V6-189ci 3.1L F/I Vin M

1998 V6-189ci 3.1L F/I Vin M

1997 V6-189ci 3.1L F/I Vin M

1996 L4-134ci 2.2L F/I Vin 4

1996 V6-189ci 3.1L F/I Vin M

1995 L4-134ci 2.2L F/I Vin 4

1994 L4-134ci 2.2L F/I Vin 4

LESABRE(4)1996-1999

1999 V6-231ci 3.8L F/I Vin K

1998 V6-231ci 3.8L F/I Vin K

1997 V6-231ci 3.8L F/I Vin K

1996 V6-231ci 3.8L F/I Vin K

PARK AVENUE(6)1995-1999

1999 V6-231ci 3.8L F/I S/C Vin 1

1999 V6-231ci 3.8L F/I Vin K

1998 V6-231ci 3.8L F/I Vin K

1997 V6-231ci 3.8L F/I Vin K

1996 V6-231ci 3.8L F/I Vin K

1995 V6-231ci 3.8L F/I Vin K

PARK AVENUE ULTRA(3)1996-1998

1998 V6-231ci 3.8L F/I S/C Vin 1 (ULTRA)

1997 V6-231ci 3.8L F/I S/C Vin 1 (ULTRA)

1996 V6-231ci 3.8L F/I S/C Vin 1 (ULTRA)

REGAL(13)1996-2002

2002 V6-231ci 3.8L F/I S/C Vin 1 (GS)

2002 V6-231ci 3.8L F/I Vin K (LS)

2001 V6-231ci 3.8L F/I S/C Vin 1 (GS)

2001 V6-231ci 3.8L F/I Vin K (LS)

2000 V6-231ci 3.8L F/I Vin K

2000 V6-231ci 3.8L F/I S/C Vin 1

1999 V6-231ci 3.8L F/I S/C Vin 1

1999 V6-231ci 3.8L F/I Vin K

1998 V6-231ci 3.8L F/I Vin K (LS)

1997 V6-231ci 3.8L F/I Vin K (LS)

1997 V6-231ci 3.8L F/I S/C Vin 1 (GS)

1996 V6-189ci 3.1L F/I Vin M

1996 V6-231ci 3.8L F/I Vin K

REGAL GS(1)1998-1998

1998 V6-231ci 3.8L F/I S/C Vin 1 (GS)

RIVIERA(7)1995-1999

1999 V6-231ci 3.8L F/I S/C Vin 1

1998 V6-231ci 3.8L F/I S/C Vin 1

1997 V6-231ci 3.8L F/I Vin K

1997 V6-231ci 3.8L F/I S/C Vin 1

1996 V6-231ci 3.8L F/I Vin K

1996 V6-231ci 3.8L F/I S/C Vin 1

1995 V6-231ci 3.8L F/I Vin K

SKYLARK(1)1996-1996

1996 V6-189ci 3.1L F/I Vin M

CHEVROLET(40)1992-2001

BERETTA(4)1994-1996

1996 L4-134ci 2.2L F/I Vin 4

1996 V6-189ci 3.1L F/I Vin M

1995 L4-134ci 2.2L F/I Vin 4

1994 L4-134ci 2.2L F/I Vin 4

CAMARO(5)1995-1999

1999 V6-231ci 3.8L F/I Vin K

1998 V6-231ci 3.8L F/I Vin K

1997 V6-231ci 3.8L F/I Vin K

1996 V6-231ci 3.8L F/I Vin K

1995 V6-231ci 3.8L F/I Vin K

CAVALIER(3)1992-1994

1994 L4-134ci 2.2L F/I Vin 4

1993 L4-134ci 2.2L F/I Vin 4

1992 L4-134ci 2.2L F/I Vin 4

CORSICA(4)1994-1996

1996 L4-134ci 2.2L F/I Vin 4

1996 V6-189ci 3.1L F/I Vin M

1995 L4-134ci 2.2L F/I Vin 4

1994 L4-134ci 2.2L F/I Vin 4

LLV (POSTAL VEHICLE)(2)1994-1995

1995 L4-134ci 2.2L F/I Vin 4

1994 L4-134ci 2.2L F/I Vin 4

LUMINA(7)1996-2001

2001 V6-189ci 3.1L F/I Vin J

2000 V6-189ci 3.1L F/I Vin J

1999 V6-189ci 3.1L F/I Vin M

1999 V6-231ci 3.8L F/I Vin K

1998 V6-189ci 3.1L F/I Vin M

1997 V6-189ci 3.1L F/I Vin M

1996 V6-189ci 3.1L F/I Vin M

LUMINA APV(1)1996-1996

1996 V6-207ci 3.4L F/I Vin E

LUMINA LTZ(1)1998-1998

1998 V6-231ci 3.8L F/I Vin K

MONTE CARLO(5)1996-1999

1999 V6-189ci 3.1L F/I Vin M

1999 V6-231ci 3.8L F/I Vin K

1998 V6-189ci 3.1L F/I Vin M

1997 V6-189ci 3.1L F/I Vin M

1996 V6-189ci 3.1L F/I Vin M

MONTE CARLO Z34(1)1998-1998

1998 V6-231ci 3.8L F/I Vin K (Z34)

PICKUP S10/T10(4)1994-1997

1997 L4-134ci 2.2L F/I Vin 4

1996 L4-134ci 2.2L F/I Vin 4

1995 L4-134ci 2.2L F/I Vin 4

1994 L4-134ci 2.2L F/I Vin 4

VENTURE(3)1997-1999

1999 V6-207ci 3.4L F/I Vin E

1998 V6-207ci 3.4L F/I Vin E

1997 V6-207ci 3.4L F/I Vin E

CHEVY MD TRK(8)1991-1998

B6P042(1)1991-1991

1991 V8-366ci 6.0L F/I Vin GM

B7T042(3)1993-1995

1995 V8-366ci 6.0L F/I Vin GM

1994 V8-366ci 6.0L F/I Vin GM

1993 V8-366ci 6.0L F/I Vin GM

F6B042(2)1997-1998

1998 V8-366ci 6.0L F/I Vin GM

1997 V8-366ci 6.0L F/I Vin GM

F7B042(2)1997-1998

1998 V8-366ci 6.0L F/I Vin GM

1997 V8-366ci 6.0L F/I Vin GM

GMC(4)1994-1997

PICKUP SONOMA (S15/T15)(4)1994-1997

1997 L4-134ci 2.2L F/I Vin 4

1996 L4-134ci 2.2L F/I Vin 4

1995 L4-134ci 2.2L F/I Vin 4

1994 L4-134ci 2.2L F/I Vin 4

GMC MD TRK(8)1991-1998

B6000 B6P SCHOOL BUS(1)1991-1991

1991 V8-366ci 6.0L F/I Vin GM

B7 SERIES SCHOOL BUS(3)1993-1995

1995 V8-366ci 6.0L F/I Vin GM

1994 V8-366ci 6.0L F/I Vin GM

1993 V8-366ci 6.0L F/I Vin GM

F6(2)1997-1998

1998 V8-366ci 6.0L F/I Vin GM

1997 V8-366ci 6.0L F/I Vin GM

F7(2)1997-1998

1998 V8-366ci 6.0L F/I Vin GM

1997 V8-366ci 6.0L F/I Vin GM

OLDSMOBILE(30)1994-1999

ACHIEVA(1)1996-1996

1996 V6-189ci 3.1L F/I Vin M

CUTLASS CIERA(4)1994-1996

1996 L4-134ci 2.2L F/I Vin 4

1996 V6-189ci 3.1L F/I Vin M

1995 L4-134ci 2.2L F/I Vin 4

1994 L4-134ci 2.2L F/I Vin 4

CUTLASS SUPREME(2)1996-1997

1997 V6-189ci 3.1L F/I Vin M

1996 V6-189ci 3.1L F/I Vin M

DELTA 88(1)1999-1999

1999 V6-231ci 3.8L F/I Vin K

EIGHTY-EIGHT(3)1996-1998

1998 V6-231ci 3.8L F/I Vin K

1997 V6-231ci 3.8L F/I Vin K

1996 V6-231ci 3.8L F/I Vin K

EIGHTY-EIGHT LSS(2)1996-1996

1996 V6-231ci 3.8L F/I Vin K

1996 V6-231ci 3.8L F/I S/C Vin 1

EIGHTY-EIGHT ROYALE(1)1995-1995

1995 V6-231ci 3.8L F/I Vin K

INTRIGUE(2)1998-1999

1999 V6-231ci 3.8L F/I Vin K

1998 V6-231ci 3.8L F/I Vin K

LSS(6)1997-1999

1999 V6-231ci 3.8L F/I S/C Vin 1

1999 V6-231ci 3.8L F/I Vin K

1998 V6-231ci 3.8L F/I Vin K

1998 V6-231ci 3.8L F/I S/C Vin 1

1997 V6-231ci 3.8L F/I Vin K

1997 V6-231ci 3.8L F/I S/C Vin 1

NINETY-EIGHT REGENCY(2)1995-1996

1996 V6-231ci 3.8L F/I Vin K

1995 V6-231ci 3.8L F/I Vin K

REGENCY(2)1997-1998

1998 V6-231ci 3.8L F/I Vin K

1997 V6-231ci 3.8L F/I Vin K

SILHOUETTE (OLDS)(4)1996-1999

1999 V6-207ci 3.4L F/I Vin E

1998 V6-207ci 3.4L F/I Vin E

1997 V6-207ci 3.4L F/I Vin E

1996 V6-207ci 3.4L F/I Vin E

PONTIAC(44)1992-2003

BONNEVILLE(5)1997-1999

1999 V6-231ci 3.8L F/I S/C Vin 1

1999 V6-231ci 3.8L F/I Vin K

1998 V6-231ci 3.8L F/I Vin K

1997 V6-231ci 3.8L F/I Vin K

1997 V6-231ci 3.8L F/I S/C Vin 1

BONNEVILLE SE(2)1995-1996

1996 V6-231ci 3.8L F/I Vin K

1995 V6-231ci 3.8L F/I Vin K

BONNEVILLE SSE(1)1996-1996

1996 V6-231ci 3.8L F/I S/C Vin 1

BONNEVILLE SSEi(1)1998-1998

1998 V6-231ci 3.8L F/I S/C Vin 1

FIREBIRD(5)1995-1999

1999 V6-231ci 3.8L F/I Vin K

1998 V6-231ci 3.8L F/I Vin K

1997 V6-231ci 3.8L F/I Vin K

1996 V6-231ci 3.8L F/I Vin K

1995 V6-231ci 3.8L F/I Vin K

GRAND AM(1)1996-1996

1996 V6-189ci 3.1L F/I Vin M

GRAND PRIX(19)1996-2003

2003 V6-189ci 3.1L F/I Vin J

2003 V6-231ci 3.8L F/I Vin K

2003 V6-231ci 3.8L F/I S/C Vin 1

2002 V6-189ci 3.1L F/I Vin J

2002 V6-231ci 3.8L F/I S/C Vin 1

2002 V6-231ci 3.8L F/I Vin K

2001 V6-231ci 3.8L F/I Vin K

2001 V6-189ci 3.1L F/I Vin J

2000 V6-189ci 3.1L F/I Vin J

2000 V6-231ci 3.8L F/I Vin K

1999 V6-189ci 3.1L F/I Vin M

1999 V6-231ci 3.8L F/I S/C Vin 1

1999 V6-231ci 3.8L F/I Vin K

1998 V6-189ci 3.1L F/I Vin M

1998 V6-231ci 3.8L F/I Vin K

1997 V6-189ci 3.1L F/I Vin M

1997 V6-231ci 3.8L F/I Vin K

1997 V6-231ci 3.8L F/I S/C Vin 1

1996 V6-189ci 3.1L F/I Vin M

GRAND PRIX GTP(3)1998-2001

2001 V6-231ci 3.8L F/I S/C Vin 1

2000 V6-231ci 3.8L F/I S/C Vin 1

1998 V6-231ci 3.8L F/I S/C Vin 1

MONTANA(1)1999-1999

1999 V6-207ci 3.4L F/I Vin E

SUNBIRD(3)1992-1994

1994 L4-122ci 2.0L F/I Vin H

1993 L4-122ci 2.0L F/I Vin H

1992 L4-122ci 2.0L F/I Vin H

TRANS SPORT(3)1996-1998

1998 V6-207ci 3.4L F/I Vin E

1997 V6-207ci 3.4L F/I Vin E

1996 V6-207ci 3.4L F/I Vin E

[dyeager535]

Yes I did!

An update on this. Found one of these sensors. Tried to test it with the stock gauge in the radiator fill neck, but tests were inconclusive. Although I did successfully test what happens when you shut the engine down with the radiator cap off.

I then proceeded to replicate what you did Mark. Didn't cut it down quite to .5" to start cutting threads, but the die started. Got to the base of the sensor (against the wrench flat portion) and started to back the die off. Sensor broke in half right there.

~1.05" from the sensor tip, the "wall" of the sensor housing thins way down. Towards the tip the housing thickness including cut threads, is .12". The wall thickness, including threads, up against the wrench flats is .073". Barely the thickness of the threads themselves. Glad I figured this out now, would have been frustrating to have it break while threading it in.

In other words, if anyone wondered why the CTS aren't threaded all the way to the wrench flats from the factory, now you know. I would highly advise anyone attempting this to not cut threads too far "up" the sensor. Safe would be .75" including the tip. If the portion above the threads was left the normal diameter, a washer might be usable/necessary to squeeze the drain plug seal enough.

The internals are quite complex on those sensors by the way. Surprised they can be had for ~$12.

I grabbed a two wire, I will try on it. The two wire sensor is shorter in the brass section than the three wire however, so getting enough threads to engage is going to be tough. I couldn't find any single wire units to play with.

Got a nice (looking) 1227727 for $40 this weekend though, including plugs. Found a couple more at another yard, wasn't willing to pay $70/each for them though. Prepping the senders for eventual use with this. Also going to do some research and see if I can get the VSS/radio volume control of it integrated into the early 80's style Delco radio my truck has...