When I got my Injection Technology harness they had wired it for the Cadillac sensor, 2 wire, and I had sent them the correct three wire sensor connector. I had to replace their connector with the correct one for mt three wire sensor. I do not have a clue where the single wire connector for the gauge was supposed to go. I called and they could not tell me either.
Great Customer Service?
Wanted to add I have a new AC Delco three wire sensor and its new AC Delco connector I didn't use I can sell you. -joe
[This message has been edited by josef644 (edited 02-02-2011).]
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09:29 PM
BigGuyTinyCar Member
Posts: 308 From: Los Alamos, NM Registered: Jan 2009
When I got my Injection Technology harness they had wired it for the Cadillac sensor, 2 wire, and I had sent them the correct three wire sensor connector. I had to replace their connector with the correct one for mt three wire sensor. I do not have a clue where the single wire connector for the gauge was supposed to go. I called and they could not tell me either.
Great Customer Service?
Wanted to add I have a new AC Delco three wire sensor and its new AC Delco connector I didn't use I can sell you. -joe
Thanks, Joe. That's the info I was looking for! They must have split the signal from the Caddy 2-wire sensor. That's the only thing I can think of. I'll PM you about the sensor/connector.
[This message has been edited by BigGuyTinyCar (edited 02-02-2011).]
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10:30 PM
BigGuyTinyCar Member
Posts: 308 From: Los Alamos, NM Registered: Jan 2009
Yes. As most GM vehicles do. The temp in question is 180 degrees. The PCM needs to see a coolant temp reading of 180, good switching the O2 sensor (indicates that its warm enough to read properly), and a ~60 second time delay must have passed. Then the PCM will switch to "closed loop" mode and start adjusting fuel based on O2 readings.
Yeah, I read something like that elsewhere on Pennock's, but I think the number was 176 degrees.
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Check out that T-stat. These engines seem to run best with a 195 degree one in my experiance. If that doesn't do it try disconnecting your temp gauge and see if that doesn't help a bit. Its not common practice to "T" one temp sender wire to run both the gauge and feed the PCM. This may bring about issues but I'm not positive.
That's what I was thinking. In fact, I wonder if it may even shorten the life of the sensor. That would make sense as Dan (Frizlefrak) said the cold idle problem started just recently, a few months before I bought the car from him.
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The part numbers for the newer 3 wire CTS are in micky's wiring thread. You'll need to wire in a new connector for it and run that extra wire also if you decide to go this route.
Understood. I'm definitely going to try it.
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You got a scanner? If so you can confirm what the PCM is reading for temp.
Where do you get these scanners? I have an OBD2 scanner, but that obviously won't work here.
[This message has been edited by BigGuyTinyCar (edited 02-02-2011).]
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10:38 PM
phonedawgz Member
Posts: 17091 From: Green Bay, WI USA Registered: Dec 2009
Splitting the 2 wire sensor will cause both the ECM (PCM) and gauge to get a wrong reading. If your gauge is working right, that is not what they did.
Well, the gauge is working, but I don't know if it's reading right. I reads only ~140* when fully warmed to "operating temp", and it takes a lot longer to get there (at least double the driving distance that my other cars take to get fully warmed up). So that's what I'm trying to figure out. If it is reading correctly, my thermostat must be stuck open.
[This message has been edited by BigGuyTinyCar (edited 02-05-2011).]
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11:27 PM
phonedawgz Member
Posts: 17091 From: Green Bay, WI USA Registered: Dec 2009
See if the gauge indication changes when you unplug the ECM. Start with the engine warmed some so the gauge is reading on scale. Unplug the ECM wires key off. If the gauge reads different with the ECM connected vs disconnected there is something wrong.
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11:31 PM
BigGuyTinyCar Member
Posts: 308 From: Los Alamos, NM Registered: Jan 2009
I have an AutoXray 5000. It works on OBD I and OBD II. Every body in my neighbor hood uses it when the SES light comes on. I can drive down the road and look at the scanner to see what is going on in near real time. It will also let you know what the coolant temperature is seeing as it is happening.
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11:01 AM
BigGuyTinyCar Member
Posts: 308 From: Los Alamos, NM Registered: Jan 2009
I have an AutoXray 5000. It works on OBD I and OBD II. Every body in my neighbor hood uses it when the SES light comes on. I can drive down the road and look at the scanner to see what is going on in near real time. It will also let you know what the coolant temperature is seeing as it is happening.
Sounds nice. I was looking at those on ebay and they're a little steep for me right now. What a great tool, though!
I thought I read on here somewhere that someone figured out how to use the '94-'95 (might have been other years too) Cadillac Deville cluster as a scanner.
[This message has been edited by BigGuyTinyCar (edited 02-03-2011).]
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04:45 PM
josef644 Member
Posts: 6939 From: Dickinson, Texas USA Registered: Nov 2006
Sounds nice. I was looking at those on ebay and they're a little steep for me right now. What a great tool, though!
I thought I read on here somewhere that someone figured out how to use the '94-'95 (might have been other years too) Cadillac Deville cluster as a scanner.
I think I paid around a hundred off of E Bay for mine with all of the cables and all.
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08:18 PM
Feb 5th, 2011
Fieroseverywhere Member
Posts: 4242 From: Gresham, Oregon USA Registered: Mar 2006
I thought I read on here somewhere that someone figured out how to use the '94-'95 (might have been other years too) Cadillac Deville cluster as a scanner.
Yes an no. Technically all of the 4.9 caddy's have a built in scanner, not just the 94-95's. The problem is they are complicated at best to install in a fiero. You need your PCM (obviously ), the matching BCM, the fuel data display, climate control display, and programmer. Then there is the absolute nightmare of wiring all the pieces together (literally about 100 wires for this alone).
Its a mod that would probably be worth the time. In addition to scanning abilities of the setup you can...
Cycle PCM outputs. This is especially helpful for controling the ISC motor functions when doing an idle learn. Test all the wiring circuits and sensors in the engine harness by just pressing a few buttons. Use the fuel data display to give pretty accurate real time fuel data. Data-logging. Testing the individual cylinders to check not only the function of the injectors but how well the flow of each matches the others (balance test). There is more but I don't recall all of it. We'll just say its more then any scanner can do on its own.
[This message has been edited by Fieroseverywhere (edited 02-05-2011).]
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09:52 PM
Feb 6th, 2011
BigGuyTinyCar Member
Posts: 308 From: Los Alamos, NM Registered: Jan 2009
Originally posted by Fieroseverywhere: Yes an no. Technically all of the 4.9 caddy's have a built in scanner, not just the 94-95's. The problem is they are complicated at best to install in a fiero. You need your PCM (obviously ), the matching BCM, the fuel data display, climate control display, and programmer. Then there is the absolute nightmare of wiring all the pieces together (literally about 100 wires for this alone).
Its a mod that would probably be worth the time. In addition to scanning abilities of the setup you can...
Cycle PCM outputs. This is especially helpful for controling the ISC motor functions when doing an idle learn. Test all the wiring circuits and sensors in the engine harness by just pressing a few buttons. Use the fuel data display to give pretty accurate real time fuel data. Data-logging. Testing the individual cylinders to check not only the function of the injectors but how well the flow of each matches the others (balance test). There is more but I don't recall all of it. We'll just say its more then any scanner can do on its own.
Ah. That sounds like a little more than I care to get into right now. Thanks for the info, though.
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Originally posted by phonedawgz:
See if the gauge indication changes when you unplug the ECM. Start with the engine warmed some so the gauge is reading on scale. Unplug the ECM wires key off. If the gauge reads different with the ECM connected vs disconnected there is something wrong.
Well, here's what I've found, so far. Injection Technology didn't "T" off the sensor signal to the temp gauge... They ONLY connected the sensor signal to the gauge. The E11 and E16 pins at the ECM are being fed the signal from the head temp sensor (which, as I understand it, isn't really a sensor, but a sender...it just closes when the iron head reaches a temp of ~380* to turn on the HOT dash light).
I would recommend everyone who has the Injection Technology harness for the 4.9 swap to check that the ECM is getting the proper signal from the CTS (and NOT the head temp sender). My harness was purchased on March 21, 2006, so they may have corrected that since then, but you should check anyway.
I bought the 3-wire CTS and connector from Joe and will be installing it and then rewiring the connectors as soon as the weather permits. Any gotchas I should know about when changing the CTS? Can it be done without draining coolant?
[This message has been edited by BigGuyTinyCar (edited 02-06-2011).]
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02:29 PM
phonedawgz Member
Posts: 17091 From: Green Bay, WI USA Registered: Dec 2009
My understanding of the correct word difference from sensor to sender is a sensor is an ECM input while a sender goes to a gauge.
The senders on the Fiero (Fuel Level, Oil Pressure, and Temperature Light and Temperature Gauge) are one wire senders with the return being engine ground. The stock temp sender is a dual temp light/temp gauge sender hence the two wires to the sender.
Almost all of the ECM engine control sensors are two wire sensors with the return being a separate ground wire that connects back to the ground at the ECM itself. The reason GM did that is to avoid having ground issues also turning into driveability issues.
So pin E16 Yellow connects to one side of the CTS. The ECM applies voltage to this side to read the resistance of the CTS Pin E11 connects to the other side of the CTS. On the ECM side the 5v return means ECM ground.
Q1 - Do you have a scanner and does the scanner show a CTS temp that isn't -40? I really suspect your CTS is working. -40 is what an open reads to the CTS. Usually the ECM has a back up program to say, if the CTS reads -40 and stays there, turn on the SES light and substitute some value for the temp.
Q2 - Do you have a working SES and is it giving you a SES light?
----
You could unplug the connector from the ECM and read the resistance from pin E11 to E16. This would tell you if you are getting something close to the correct resistance.
Here is the resistance look up table for the CTS sensor. You could also warm up the engine and test the resistance then.
That would tell you if the sensor is working.
I don't know that there is a "block temperature sensor". If there is I do think you didn't mean to say 380*. Seems a bit hot for your block. Anywhere there is a coolant passage that you are sensing the temperature would be a CTS I would think. Unless it is right where the cool water from the radiator enters the block.
[This message has been edited by phonedawgz (edited 02-06-2011).]
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04:09 PM
phonedawgz Member
Posts: 17091 From: Green Bay, WI USA Registered: Dec 2009
Can it be done without draining the coolant? Sure - some will leak out but just have the new one ready with thread compound or teflon tape ready before you pull the old one out. Some will spill but just be quick about it. And no, there is no way teflon tape can cause the sender part of the sensor not to electrically connect to the block.
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04:15 PM
josef644 Member
Posts: 6939 From: Dickinson, Texas USA Registered: Nov 2006
The guy named 'Jim' at Injection Tech tried to tell me that a 4.9 had a temperature sender in the head like a SBC. I tried to tell him it wasn't correct, but to no avail. You will need to identify the gauge lead and connect it to the part of the connector where one wire is by it self. I don't think it makes any difference with the other two, but wire them as Mickey_Moose posted. All will be in good working order.
[This message has been edited by josef644 (edited 02-06-2011).]
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05:39 PM
Fieroseverywhere Member
Posts: 4242 From: Gresham, Oregon USA Registered: Mar 2006
The one posted above is for a 91. The one I just posted if for the 92-93. Notice the difference in the fuel injector and CTS circuits in particular. There are other minor changes also.
[This message has been edited by Fieroseverywhere (edited 02-06-2011).]
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05:41 PM
BigGuyTinyCar Member
Posts: 308 From: Los Alamos, NM Registered: Jan 2009
My understanding of the correct word difference from sensor to sender is a sensor is an ECM input while a sender goes to a gauge.
The senders on the Fiero (Fuel Level, Oil Pressure, and Temperature Light and Temperature Gauge) are one wire senders with the return being engine ground. The stock temp sender is a dual temp light/temp gauge sender hence the two wires to the sender.
Almost all of the ECM engine control sensors are two wire sensors with the return being a separate ground wire that connects back to the ground at the ECM itself. The reason GM did that is to avoid having ground issues also turning into driveability issues.
Thanks. That makes sense and is good to know for future reference.
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So pin E16 Yellow connects to one side of the CTS. The ECM applies voltage to this side to read the resistance of the CTS Pin E11 connects to the other side of the CTS. On the ECM side the 5v return means ECM ground.
Agreed. That is the way it SHOULD be.
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Q1 - Do you have a scanner and does the scanner show a CTS temp that isn't -40? I really suspect your CTS is working. -40 is what an open reads to the CTS. Usually the ECM has a back up program to say, if the CTS reads -40 and stays there, turn on the SES light and substitute some value for the temp.
No scanner, but I put an ohm meter directly on the sensor prongs (at ambient temp which was about 30*) and I get nothing but infinite resistance. I tried it on every ohm range setting, I tried scuffing up the prongs. I also tried my old analog ohm meter and it gave the same reading (needle didn't deflect at all). The sensor appears to be dying (that would explain the low reading on the gauge and how long it takes to get a reading).
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Q2 - Do you have a working SES and is it giving you a SES light?
I don't think so as least it's never lit up.
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You could unplug the connector from the ECM and read the resistance from pin E11 to E16. This would tell you if you are getting something close to the correct resistance.
Did that too...Infinite resistance, but see below.
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I don't know that there is a "block temperature sensor". If there is I do think you didn't mean to say 380*. Seems a bit hot for your block. Anywhere there is a coolant passage that you are sensing the temperature would be a CTS I would think. Unless it is right where the cool water from the radiator enters the block.
Sorry, my fault, I meant "head", not "block" (I corrected it in my post above). It's the one down by the #8 sparkplug (assuming the cylinders are numbered the same as a SBC). From what I've read on this site, that one is not connected to coolant. It's just measuring the temp of the iron head. 380* is the number someone said was the activation temp.
Here's how I determined it was connected to that sender: I disconnected the green plug from the ECM, disconnected both the CTS plug and the head sender plug, and then disconnected the C500. I then checked the continuity between E16 and each of the sensor plugs (and then same for E11). Sure as shootin', there was continuity only with the head sender plug for both E16 and E11. The yellow and black wires on the head sender plug was also a dead give away too as they matched the colors of the wires that were in the E16 and E11, repectively.
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05:43 PM
BigGuyTinyCar Member
Posts: 308 From: Los Alamos, NM Registered: Jan 2009
The guy named 'Jim' at Injection Tech tried to tell me that a 4.9 had a temperature sender in the head like a SBC. I tried to tell him it wasn't correct, but to no avail. You will need to identify the gauge lead and connect it to the part of the connector where one wire is by it self. I don't think it makes any difference with the other two, but wire them as Mickey_Moose posted. All will be in good working order.[QUOTE]Originally posted by Fieroseverywhere:
Thanks. Have you checked to see if your E11 and E16 wires are going to the correct sensor?
The one posted above is for a 91. The one I just posted if for the 92-93. Notice the difference in the fuel injector and CTS circuits in particular. There are other minor changes also.
Thanks. Mine is a '94 , but I'm assuming it's similar. Dan (Frizlefrak) gave me a file with a bunch of those diagrams. Some of them say "Eldorado/Seville" instead of "Deville", but the differences appear to be minimal.
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06:06 PM
phonedawgz Member
Posts: 17091 From: Green Bay, WI USA Registered: Dec 2009
Yes those two wires need to be connected to a real CTS. Agreed - a just open signal sure looks like that's a switch instead of a sensor.
So yeah it sounds like the thing to do is move those two wires to a connector that connects to a real CTS that is screwed into a coolant passage. You can do it with a separate CTS and Temp Gauge Sender but the combo unit makes it easier.
I believe it is the center pin that is the gauge sender pin. I believe the two outside pins are the CTS pins. You could always read each pin to ground to find the gauge pin, and then read the other two pins, pin to pin to verify which is which.
[This message has been edited by phonedawgz (edited 02-06-2011).]
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06:27 PM
josef644 Member
Posts: 6939 From: Dickinson, Texas USA Registered: Nov 2006
Well the 'new' PCM wiring diagram has the CTS on exactly the same pins you have been testing.
Yes those two wires need to be connected to a real CTS. Agreed - a just open signal sure looks like that's a switch instead of a sensor.
So yeah it sounds like the thing to do is move those two wires to a connector that connects to a real CTS that is screwed into a coolant passage. You can do it with a separate CTS and Temp Gauge Sender but the combo unit makes it easier.
I believe it is the center pin that is the gauge sender pin. I believe the two outside pins are the CTS pins. You could always read each pin to ground to find the gauge pin, and then read the other two pins, pin to pin to verify which is which.
As he said the single pin is for the gauge. The two next to each other go to the ECM.
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07:35 PM
PFF
System Bot
phonedawgz Member
Posts: 17091 From: Green Bay, WI USA Registered: Dec 2009
Thanks a bunch, guys. So, yeah, I know how to hook everything up now. I was just surprised at the poor quality control at Injection Technology, and wanted everyone else with an IT harness to double check this error. It makes me want to go through and check all the connections now. It's not a big deal for me since I have a fair amount of experience with electrical/electronics stuff, but for the money they charge, you think you'd be able to avoid all wiring work.
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11:21 PM
Feb 7th, 2011
josef644 Member
Posts: 6939 From: Dickinson, Texas USA Registered: Nov 2006
It makes me want to go through and check all the connections now.
I removed it from my car. Using an ohm meter verified every connection, and every double connection. There are a few that have some common wire connections. My problem turned out to be a bad EPROM. Stickpony got me going with a new burn.
Info from Mickey_Moose's thread:
pin "A" BLK wire on the switch goes to ecm "E11" pin "B" YEL wire on the switch goes to ecm "E16" pin "C" GRN wire on the switch goes to C500 gage connection
I have looked for the picture of the markings on this connector, but can't find it. The locking tang on the connector had the 'A' and 'B' marked on them
[This message has been edited by josef644 (edited 02-07-2011).]
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10:28 AM
BigGuyTinyCar Member
Posts: 308 From: Los Alamos, NM Registered: Jan 2009
I removed it from my car. Using an ohm meter verified every connection, and every double connection. There are a few that have some common wire connections. My problem turned out to be a bad EPROM. Stickpony got me going with a new burn.
Did you find any errors?
quote
Info from Mickey_Moose's thread:
pin "A" BLK wire on the switch goes to ecm "E11" pin "B" YEL wire on the switch goes to ecm "E16" pin "C" GRN wire on the switch goes to C500 gage connection
I have looked for the picture of the markings on this connector, but can't find it. The locking tang on the connector had the 'A' and 'B' marked on them
Yeah I was hoping that "A" and "B" referred to the ones we're discussing. In any case, I'm assuming it's (looking down on the CTS as though it were installed)
A B .C
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12:28 PM
josef644 Member
Posts: 6939 From: Dickinson, Texas USA Registered: Nov 2006
Thanks. Mine is a '94 , but I'm assuming it's similar. Dan (Frizlefrak) gave me a file with a bunch of those diagrams. Some of them say "Eldorado/Seville" instead of "Deville", but the differences appear to be minimal.
Thats right. 94-95 deville are wired exactly as 92-93 seville/eldorado. The only real difference between those and the 92-93 deville/fleetwood is the addition of one extra wire to run the second O2 sensor. Since your not using 2 sensors its all the same.
I just prefer the diagrams for the 92-93 Deville over the 91. The injector wiring is more clear, CTS is where is should be, and the missing parts of the ignition system are included. Its the same diagram, Caddy just cleared up a few confusing parts. However they still didn't fix the pin # errors for the EGR & Purge can, annoying.
[This message has been edited by Fieroseverywhere (edited 02-07-2011).]
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07:35 PM
BigGuyTinyCar Member
Posts: 308 From: Los Alamos, NM Registered: Jan 2009
Originally posted by Fieroseverywhere: Thats right. 94-95 deville are wired exactly as 92-93 seville/eldorado. The only real difference between those and the 92-93 deville/fleetwood is the addition of one extra wire to run the second O2 sensor. Since your not using 2 sensors its all the same.
Thanks for clearing that up. I was wondering...
quote
I just prefer the diagrams for the 92-93 Deville over the 91. The injector wiring is more clear, CTS is where is should be, and the missing parts of the ignition system are included. Its the same diagram, Caddy just cleared up a few confusing parts. However they still didn't fix the pin # errors for the EGR & Purge can, annoying.
Yeah, I just noticed the EGR and purge are reversed (pinwise) on the circuit diagram relative to the pin diagram. Which is correct?
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11:02 PM
Feb 8th, 2011
Fieroseverywhere Member
Posts: 4242 From: Gresham, Oregon USA Registered: Mar 2006