New CTS, temp readings way off
03-20-2015, 04:01 PM
#11
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03-23-2015, 11:45 AM
#12
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Hopefully soon..
Have to agree on the first notion, of excluding any cluster checks, before going to "swap ECM". I'm not quite sure how the cluster comes into play here though. As far as I could read, the paper only covers the ECM side and related loom. Unless there's a short, they're entirely speparate circuits. Temps read by VAG 1598 test box, on "engine side" only. And, they do go on with manual resistance/continuity control of the wiring loom.
All in all, I don't see how the cluster could affect the outcome when including all these steps - but please enlighten me, I live to learn
New, Audi original CTS arrived today, but nut until after dark - street parking, no lights. So haven't gotten to pull the "new", suspected sensor yet - need the car working, those times it decides it wants to.
I did however, throw both the original CTS that got swapped out, and the Audi genuine one, that arrived today - together in a pot. Measured them both at 10'C intervals. The new original is within resistance range from 30 to 90, didn't check below and got a bit too hot to check above. The old one lost continuity above 40, so thats clearly gone - "cluster side" no continuity regardless of temperature.
So the new, new one - should be good. Hopefully it'll play equally nice once its in place. Anyone got any idea about the correct resistance ranges for the cluster side thermistor (2-4/A-B) though? The values I measured were very close to 60% of the engine side(1-3/C-D) resistance, across the board.
All in all, I don't see how the cluster could affect the outcome when including all these steps - but please enlighten me, I live to learn
New, Audi original CTS arrived today, but nut until after dark - street parking, no lights. So haven't gotten to pull the "new", suspected sensor yet - need the car working, those times it decides it wants to.
I did however, throw both the original CTS that got swapped out, and the Audi genuine one, that arrived today - together in a pot. Measured them both at 10'C intervals. The new original is within resistance range from 30 to 90, didn't check below and got a bit too hot to check above. The old one lost continuity above 40, so thats clearly gone - "cluster side" no continuity regardless of temperature.
So the new, new one - should be good. Hopefully it'll play equally nice once its in place. Anyone got any idea about the correct resistance ranges for the cluster side thermistor (2-4/A-B) though? The values I measured were very close to 60% of the engine side(1-3/C-D) resistance, across the board.
Last edited by pr0xZen; 03-23-2015 at 12:13 PM.
03-23-2015, 03:38 PM
#13
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Have to agree on the first notion, of excluding any cluster checks, before going to "swap ECM". I'm not quite sure how the cluster comes into play here though. As far as I could read, the paper only covers the ECM side and related loom. Unless there's a short, they're entirely speparate circuits. Temps read by VAG 1598 test box, on "engine side" only. And, they do go on with manual resistance/continuity control of the wiring loom.
All in all, I don't see how the cluster could affect the outcome when including all these steps - but please enlighten me, I live to learn
New, Audi original CTS arrived today, but nut until after dark - street parking, no lights. So haven't gotten to pull the "new", suspected sensor yet - need the car working, those times it decides it wants to.
I did however, throw both the original CTS that got swapped out, and the Audi genuine one, that arrived today - together in a pot. Measured them both at 10'C intervals. The new original is within resistance range from 30 to 90, didn't check below and got a bit too hot to check above. The old one lost continuity above 40, so thats clearly gone - "cluster side" no continuity regardless of temperature.
So the new, new one - should be good. Hopefully it'll play equally nice once its in place. Anyone got any idea about the correct resistance ranges for the cluster side thermistor (2-4/A-B) though? The values I measured were very close to 60% of the engine side(1-3/C-D) resistance, across the board.
All in all, I don't see how the cluster could affect the outcome when including all these steps - but please enlighten me, I live to learn
New, Audi original CTS arrived today, but nut until after dark - street parking, no lights. So haven't gotten to pull the "new", suspected sensor yet - need the car working, those times it decides it wants to.
I did however, throw both the original CTS that got swapped out, and the Audi genuine one, that arrived today - together in a pot. Measured them both at 10'C intervals. The new original is within resistance range from 30 to 90, didn't check below and got a bit too hot to check above. The old one lost continuity above 40, so thats clearly gone - "cluster side" no continuity regardless of temperature.
So the new, new one - should be good. Hopefully it'll play equally nice once its in place. Anyone got any idea about the correct resistance ranges for the cluster side thermistor (2-4/A-B) though? The values I measured were very close to 60% of the engine side(1-3/C-D) resistance, across the board.
You should be able to do a quick short 2&4 on the harness connector to see a bump on the gauge to ensure it does see a signal.
Last edited by jcman; 03-23-2015 at 05:09 PM.
03-23-2015, 05:34 PM
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On your sensor G62/G2 the G62 side is pin 4 "Ground" and pin 2 "From the Cluster" and you are right the pdf I provided makes no mention of the gauge side resistance values or test, however it should be in the same resistance value area as the G2 side unless the reference voltage from the #2 cluster pin is different from the ECU pin #1, I doubt that.
You should be able to do a quick short 2&4 on the harness connector to see a bump on the gauge to ensure it does see a signal.
You should be able to do a quick short 2&4 on the harness connector to see a bump on the gauge to ensure it does see a signal.
Its 2.30 in the a.m. here, and not quite sure wether I misinterpreted something, missed something... all I know is that testing per the PDF, gave values fairly well within the graphs. And testing on the other two pins (2 and 4), gave a pretty much identical graph, but all values 59-61% lower than its "pin 1-3 counterpart". Shows the thermistor across those pins is physically working as a thermistor should. But you're saying the values are off, they should be identical on both thermistors?
If I apply the values across 2-4 to the 1-3 graph given, this would suggest the cluster will pretty much always display 10'C more than the actual coolant temperature, and 10'C more than what the ECU is seeing.
Does the cluster reading, have an impact on anything else than "just" the cluster gauge? This is Norway - its not like overheating is an everyday issue.
03-23-2015, 05:37 PM
#15
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pr0xZen it would also be helpful to know what the actual month/year your car was built along with the engine code, I assume you do have an analog clock as you did mention. There may be a bit of a difference between North American and your region (North UK I presume) C5's, the Bentley Ebahn wiring diagrams of 98 and 99 do show the G62/G2 pin-outs to be similar in relation to the ECU and cluster with the old style connector vs. the newer D-type that I have on my 04 A6 as you saw in the pdf.
Last edited by jcman; 03-23-2015 at 06:00 PM.
03-23-2015, 05:50 PM
#16
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I'm not quite sure if I'm following correctly; The G62 side is the cluster side? (and G2 is the engine side?) - Because AFAIK the PDF you posted, gives instructions and values exclusively for testing the ECU side, and those instructions details pin 1 and 3 (Square type CTS/plug).
Its 2.30 in the a.m. here, and not quite sure wether I misinterpreted something, missed something... all I know is that testing per the PDF, gave values fairly well within the graphs. And testing on the other two pins (2 and 4), gave a pretty much identical graph, but all values 59-61% lower than its "pin 1-3 counterpart". Shows the thermistor across those pins is physically working as a thermistor should. But you're saying the values are off, they should be identical on both thermistors?
If I apply the values across 2-4 to the 1-3 graph given, this would suggest the cluster will pretty much always display 10'C more than the actual coolant temperature, and 10'C more than what the ECU is seeing.
Does the cluster reading, have an impact on anything else than "just" the cluster gauge? This is Norway - its not like overheating is an everyday issue.
Its 2.30 in the a.m. here, and not quite sure wether I misinterpreted something, missed something... all I know is that testing per the PDF, gave values fairly well within the graphs. And testing on the other two pins (2 and 4), gave a pretty much identical graph, but all values 59-61% lower than its "pin 1-3 counterpart". Shows the thermistor across those pins is physically working as a thermistor should. But you're saying the values are off, they should be identical on both thermistors?
If I apply the values across 2-4 to the 1-3 graph given, this would suggest the cluster will pretty much always display 10'C more than the actual coolant temperature, and 10'C more than what the ECU is seeing.
Does the cluster reading, have an impact on anything else than "just" the cluster gauge? This is Norway - its not like overheating is an everyday issue.
I can't confirm that the gauge side of G62 2-4 are the same values, just a logical thought.
As long as the ECU see's the G2 part of engine temp in range and no CEL codes are present your good, you always have a oil temp gauge....correct.
BTW, North East Ohio saw record breaking temps this winter....I hear you brother, I hope our summer is mild too.
Last edited by jcman; 03-23-2015 at 05:59 PM.
03-23-2015, 06:02 PM
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I'm not 100% certain to be honest, especially regarding month. Car was delivered one of the last days in December, 98 - 10th cipher in VIN says 99 (X). Manufactured : W (Germany). VIN ends with XN055772. Option X1C (National sales program Norway) if of any relevance. Type: 4B50L5 - Engine: AGA (070270), Gearbox: DWP
The cluster is the older type (analog clock, VDO 10) . It does have an integrated immobilizer though (thought the old analog clock didn't have those? VCDS clearly gives the immo ident as Subsystem 1 when checking the cluster (17), but attempting to connect to the immo module (25) only gives up a referral to module/address 17 in the part no. / component field).
I'm having slight dificulties envisioning the how the two different types/forms of CTS is wired up, the PDF was sly enough to give numbers for one, letters for the other. But there's two thermistors and four pins in both - not a whole lot of options.
Edit: The logical notion that both thermistors would be identical, makes perfect sense to me. Would make manufacturing and quality control a lot cheaper and easier. But then again - the only real practical reason I see for actually having two separate thermistors in that sensor, is that it /had/ to be two separate values. No idea if that is anywhere near the case though. Given than the "really important one" can/will fail with NO indication for the driver unless actually pulling VAG codes (No cluster warning at all) - it seems like a "compromise choice" by the engineers.
The cluster is the older type (analog clock, VDO 10) . It does have an integrated immobilizer though (thought the old analog clock didn't have those? VCDS clearly gives the immo ident as Subsystem 1 when checking the cluster (17), but attempting to connect to the immo module (25) only gives up a referral to module/address 17 in the part no. / component field).
I'm having slight dificulties envisioning the how the two different types/forms of CTS is wired up, the PDF was sly enough to give numbers for one, letters for the other. But there's two thermistors and four pins in both - not a whole lot of options.
Edit: The logical notion that both thermistors would be identical, makes perfect sense to me. Would make manufacturing and quality control a lot cheaper and easier. But then again - the only real practical reason I see for actually having two separate thermistors in that sensor, is that it /had/ to be two separate values. No idea if that is anywhere near the case though. Given than the "really important one" can/will fail with NO indication for the driver unless actually pulling VAG codes (No cluster warning at all) - it seems like a "compromise choice" by the engineers.
Last edited by pr0xZen; 03-23-2015 at 06:15 PM.
03-23-2015, 06:31 PM
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Oh man, I think I need to have a look at this after a couple of hours of sleep. I could barely make out which one (G2/G62) gronds at the cluster. The gauge part made no sense.
TBH, I hadn't seen this type of diagram until a couple of days ago, slowly attempting to figure out "gremlins" with heated seat, power windows, heating side mirror etc (all driver side) - but thats a different story. This is my first post-95, "proper" car - all before them have been simpler and older, Opels and Hondas. So over the years I started to get the hang of the Haynes manual diagrams. These VAG diagrams are different animals, so a slight learning curve. Have to wrap my head around these different break-ups, tracks and number referrals.
Should have stuck with electrics in tech college.
TBH, I hadn't seen this type of diagram until a couple of days ago, slowly attempting to figure out "gremlins" with heated seat, power windows, heating side mirror etc (all driver side) - but thats a different story. This is my first post-95, "proper" car - all before them have been simpler and older, Opels and Hondas. So over the years I started to get the hang of the Haynes manual diagrams. These VAG diagrams are different animals, so a slight learning curve. Have to wrap my head around these different break-ups, tracks and number referrals.
Should have stuck with electrics in tech college.
03-23-2015, 06:31 PM
#20
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I'm not 100% certain to be honest, especially regarding month. Car was delivered one of the last days in December, 98 - 10th cipher in VIN says 99 (X). Manufactured : W (Germany). VIN ends with XN055772. Option X1C (National sales program Norway) if of any relevance. Type: 4B50L5 - Engine: AGA (070270), Gearbox: DWP
The cluster is the older type (analog clock, VDO 10) . It does have an integrated immobilizer though (thought the old analog clock didn't have those? VCDS clearly gives the immo ident as Subsystem 1 when checking the cluster (17), but attempting to connect to the immo module (25) only gives up a referral to module/address 17 in the part no. / component field).
I'm having slight dificulties envisioning the how the two different types/forms of CTS is wired up, the PDF was sly enough to give numbers for one, letters for the other. But there's two thermistors and four pins in both - not a whole lot of options.
Edit: The logical notion that both thermistors would be identical, makes perfect sense to me. Would make manufacturing and quality control a lot cheaper and easier. But then again - the only real practical reason I see for actually having two separate thermistors in that sensor, is that it /had/ to be two separate values. No idea if that is anywhere near the case though. Given than the "really important one" can/will fail with NO indication for the driver unless actually pulling VAG codes (No cluster warning at all) - it seems like a "compromise choice" by the engineers.
The cluster is the older type (analog clock, VDO 10) . It does have an integrated immobilizer though (thought the old analog clock didn't have those? VCDS clearly gives the immo ident as Subsystem 1 when checking the cluster (17), but attempting to connect to the immo module (25) only gives up a referral to module/address 17 in the part no. / component field).
I'm having slight dificulties envisioning the how the two different types/forms of CTS is wired up, the PDF was sly enough to give numbers for one, letters for the other. But there's two thermistors and four pins in both - not a whole lot of options.
Edit: The logical notion that both thermistors would be identical, makes perfect sense to me. Would make manufacturing and quality control a lot cheaper and easier. But then again - the only real practical reason I see for actually having two separate thermistors in that sensor, is that it /had/ to be two separate values. No idea if that is anywhere near the case though. Given than the "really important one" can/will fail with NO indication for the driver unless actually pulling VAG codes (No cluster warning at all) - it seems like a "compromise choice" by the engineers.
I saw that too on the CTS connector letter/number pin-out descriptions.
The info display should show a red overheat symbol as well and I'm not sure if that is on the cluster side of the CTS, probably so, but then a CEL would come on if the ECU side fails. German engineers are very meticulous and exact...bean counters are bean counters.