'88 S4 belt tension warning - false?
#31
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JP
When the logical checks fail to yield a result one has to start looking "outside the box" in the search for an illogical cause to give a logical answer.
Wiring inside our cars is [for the most part] not prone to failure but clearly something has failed in your case. Rodent attack is just one posibility, other possibilities like little ones poking around with a screw driver become more probable once you eliminate the more obvious causes. Maybe the logic solver itself has failed whatever it may happen to be.
Rgds
Fred
When the logical checks fail to yield a result one has to start looking "outside the box" in the search for an illogical cause to give a logical answer.
Wiring inside our cars is [for the most part] not prone to failure but clearly something has failed in your case. Rodent attack is just one posibility, other possibilities like little ones poking around with a screw driver become more probable once you eliminate the more obvious causes. Maybe the logic solver itself has failed whatever it may happen to be.
Rgds
Fred
#32
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Thread Starter
I just connected the DMM to ground & the wire to the plugged in connector - engine running. DMM was still set to 2kΩ. I got a -.34Ω reading suggesting less of a ground???
I turned the engine off, key on, set the DMM to 20v, connected it up and nothing more than .001v.
If this were an '02 Civic, I'd just head to the track and have fun regardless of a warning like this. But even though my gut tells me that the belt will be fine for one day at the track, that big red ! that pops up with the warning will keep me from relaxing.
I turned the engine off, key on, set the DMM to 20v, connected it up and nothing more than .001v.
If this were an '02 Civic, I'd just head to the track and have fun regardless of a warning like this. But even though my gut tells me that the belt will be fine for one day at the track, that big red ! that pops up with the warning will keep me from relaxing.
#33
0° TDC with the cam gear notch at the tab, cold engine; Kemph tool gap measured at the belt tooth closest to the center cover; tool was oriented so that lifting up moved the gauge like in Kibort's picture here (he has the center cover off - mine was on).
; lifted up until the tool made contact with the back of the cover; indicated the far end of the notch/window (end closest to the engine).
Now that I'm going over it in my mind, at one point I may have pushed the car backward a foot or two when in 2nd (engine turning backward). I know that's fine when lining up timing marks, but probably not fine when doing a belt tension test. I'm trying to think of everything here...
Fred, this go-round I didn't rebuild the tensioner - or even have the center cover off. I just checked the belt tension and added oil. The tb/wp/tensioner job was done a couple of years ago. Belt was retensioned last year. All was good for several hours of track time. The tension warning appeared on its own - not after a specific job. I tested continuity between the thru-case pin with the connector/plug disconnected and the engine block. Now you have me thinking of this, I might plug the connector back in and test for continuity by poking through the insulation of the wiring from the plug to the cluster. It can't hurt.
John, at first, the plug wouldn't stay in the hole in the cover. Kevin had made a little metal external retainer that held it in by pressing down on the connector. Since that wasn't stock, I decided to correct the issue of a loose fit. I suspected that the socket wasn't clamping on the pin, so I crimped it slightly. The plug now snaps onto the pin. I'm not saying that the wiring beyond the connector in the direction of the harness is good - I didn't see any chafing.
Dave, I'm definitely not ruling out a cluster f*ck. If the warning reappears after disconnecting from the tensioner and grounding the connector, I guess I'm heading in that direction. I'll find out when I ground the connector today.
; lifted up until the tool made contact with the back of the cover; indicated the far end of the notch/window (end closest to the engine).
Now that I'm going over it in my mind, at one point I may have pushed the car backward a foot or two when in 2nd (engine turning backward). I know that's fine when lining up timing marks, but probably not fine when doing a belt tension test. I'm trying to think of everything here...
Fred, this go-round I didn't rebuild the tensioner - or even have the center cover off. I just checked the belt tension and added oil. The tb/wp/tensioner job was done a couple of years ago. Belt was retensioned last year. All was good for several hours of track time. The tension warning appeared on its own - not after a specific job. I tested continuity between the thru-case pin with the connector/plug disconnected and the engine block. Now you have me thinking of this, I might plug the connector back in and test for continuity by poking through the insulation of the wiring from the plug to the cluster. It can't hurt.
John, at first, the plug wouldn't stay in the hole in the cover. Kevin had made a little metal external retainer that held it in by pressing down on the connector. Since that wasn't stock, I decided to correct the issue of a loose fit. I suspected that the socket wasn't clamping on the pin, so I crimped it slightly. The plug now snaps onto the pin. I'm not saying that the wiring beyond the connector in the direction of the harness is good - I didn't see any chafing.
Dave, I'm definitely not ruling out a cluster f*ck. If the warning reappears after disconnecting from the tensioner and grounding the connector, I guess I'm heading in that direction. I'll find out when I ground the connector today.
#34
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JP--
The toothed belt sensor (WSM Wiring Diagram Name) connects to the CE panel at W25, passes directly through and out at P21. P21 routes to pin 4 in one of the three the instrument cluster connectors via a blue-with-brown-tracer wire. I would remove and reseat those connectors one by one, maybe with some DeOxit in the process. When you pull the one that has the blue-with-brown-tracer wire in pin 4, test it for continuity to ground, confirming the integrity of the conductor between P21 and the instrument cluster connector. If you have ground potential at P21, W25, and the switch, and also at the blue-with-brown-tracer wire at the instrument cluster, you have a bad connection at the cluster or the instrument cluster has a problem.
Clear as mud? Let me know what I can expand to help you.
With the connectors all in place, your DMM should show connection to ground in resistance mode. Try the back of P21 first. If that doesn't show continuity to ground, go to W25. If W25 is ground and P21 is not, there's a break or loose connection at the CE panel. If neither shows continuity to ground, there's a break in the conductor between the plug in the belt cover through the harness to W25. That conductor is Brown-with-White-Tracer, with no connectors between the cover and the CE panel connection.
If there is continuity to ground at P21 yet you still have the warnings, move to the
The toothed belt sensor (WSM Wiring Diagram Name) connects to the CE panel at W25, passes directly through and out at P21. P21 routes to pin 4 in one of the three the instrument cluster connectors via a blue-with-brown-tracer wire. I would remove and reseat those connectors one by one, maybe with some DeOxit in the process. When you pull the one that has the blue-with-brown-tracer wire in pin 4, test it for continuity to ground, confirming the integrity of the conductor between P21 and the instrument cluster connector. If you have ground potential at P21, W25, and the switch, and also at the blue-with-brown-tracer wire at the instrument cluster, you have a bad connection at the cluster or the instrument cluster has a problem.
Clear as mud? Let me know what I can expand to help you.
With the connectors all in place, your DMM should show connection to ground in resistance mode. Try the back of P21 first. If that doesn't show continuity to ground, go to W25. If W25 is ground and P21 is not, there's a break or loose connection at the CE panel. If neither shows continuity to ground, there's a break in the conductor between the plug in the belt cover through the harness to W25. That conductor is Brown-with-White-Tracer, with no connectors between the cover and the CE panel connection.
If there is continuity to ground at P21 yet you still have the warnings, move to the
#35
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JP--
The toothed belt sensor (WSM Wiring Diagram Name) connects to the CE panel at W25, passes directly through and out at K22. K22 routes to pin 9 in the black instrument cluster warning-unit connector via a blue-with-brown-tracer wire. I would remove and reseat those connectors one by one, maybe with some DeOxit in the process. When you pull the one that has the blue-with-brown-tracer wire in pin 9, test it for continuity to ground, confirming the integrity of the conductor between K22 and the instrument cluster connector. If you have ground potential at K22, W25, and the switch, and also at the blue-with-brown-tracer wire at the instrument cluster, you have a bad connection at the cluster or the instrument cluster has a problem.
With the connectors all in place, your DMM should show connection to ground in resistance mode. Try the back of K22 first. If that doesn't show continuity to ground, go to W25. If W25 is ground and K22 is not, there's a break or loose connection at the CE panel. If neither shows continuity to ground, there's a break in the conductor between the plug in the belt cover through the harness to W25. That conductor is Brown-with-White-Tracer, with no connectors between the cover and the CE panel connection.
If there is continuity to ground at K22 yet you still have the warnings, move to the warning system plug and test for continuity to ground from that connector pin 9. If you have continuity to ground yet still have the warning, there's a bad connection to the warning system controller or the controller has failed.
Clear as mud? Let me know what I can expand to help you.
The toothed belt sensor (WSM Wiring Diagram Name) connects to the CE panel at W25, passes directly through and out at K22. K22 routes to pin 9 in the black instrument cluster warning-unit connector via a blue-with-brown-tracer wire. I would remove and reseat those connectors one by one, maybe with some DeOxit in the process. When you pull the one that has the blue-with-brown-tracer wire in pin 9, test it for continuity to ground, confirming the integrity of the conductor between K22 and the instrument cluster connector. If you have ground potential at K22, W25, and the switch, and also at the blue-with-brown-tracer wire at the instrument cluster, you have a bad connection at the cluster or the instrument cluster has a problem.
With the connectors all in place, your DMM should show connection to ground in resistance mode. Try the back of K22 first. If that doesn't show continuity to ground, go to W25. If W25 is ground and K22 is not, there's a break or loose connection at the CE panel. If neither shows continuity to ground, there's a break in the conductor between the plug in the belt cover through the harness to W25. That conductor is Brown-with-White-Tracer, with no connectors between the cover and the CE panel connection.
If there is continuity to ground at K22 yet you still have the warnings, move to the warning system plug and test for continuity to ground from that connector pin 9. If you have continuity to ground yet still have the warning, there's a bad connection to the warning system controller or the controller has failed.
Clear as mud? Let me know what I can expand to help you.
Last edited by dr bob; 09-07-2016 at 04:30 PM. Reason: Changed year, was 1991 now 1988 MY
#36
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[Duplicate Post]
#37
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Thread Starter
Sean, doubting my tension check, I'm back in. A picture speaks 1000 words:
At this degree of tension, I can't imagine the warning to consistently trip, right?
Bob, thanks a ton for the research on the 'cluster' end of this system. I'm going to decipher everything you say here and have a go at it. Reseating and cleaning contacts certainly can't hurt, even if it's not the issue.
At this degree of tension, I can't imagine the warning to consistently trip, right?
Bob, thanks a ton for the research on the 'cluster' end of this system. I'm going to decipher everything you say here and have a go at it. Reseating and cleaning contacts certainly can't hurt, even if it's not the issue.
#39
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I just got done doing that - for good measure. Also I just realized that moving just one belt tooth away from the cam gear or toward the center cover, gives a looser belt reading of about 25% of the window. Before snugging up the belt, I measured a tooth closer to the center case (I had to maneuver the tool a bit) and it read only halfway in the window.
Now I'm at the tightest end of the window, measured from the absolute closest tooth to the center cover.
Now I'm at the tightest end of the window, measured from the absolute closest tooth to the center cover.
#40
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JP, I need to do a little editing. For some unknown reason, I was looking at the 1991 diagrams. Give me a few minutes...
Done.
Done.
#41
Sean, doubting my tension check, I'm back in. A picture speaks 1000 words:
At this degree of tension, I can't imagine the warning to consistently trip, right?
Bob, thanks a ton for the research on the 'cluster' end of this system. I'm going to decipher everything you say here and have a go at it. Reseating and cleaning contacts certainly can't hurt, even if it's not the issue.
At this degree of tension, I can't imagine the warning to consistently trip, right?
Bob, thanks a ton for the research on the 'cluster' end of this system. I'm going to decipher everything you say here and have a go at it. Reseating and cleaning contacts certainly can't hurt, even if it's not the issue.
#42
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Thread Starter
OK, so another lesson learned. I thought that the tension warning indicated a considerably loose belt, not one just a hair under the tightest setting. Should I maybe go a bit past the tight end of the window?
I'm starting to think that the belt may be stretching more than spec when it gets hot...is that common?
I believe it's a Gates.
I'm starting to think that the belt may be stretching more than spec when it gets hot...is that common?
I believe it's a Gates.
#43
OK, so another lesson learned. I thought that the tension warning indicated a considerably loose belt, not one just a hair under the tightest setting. Should I maybe go a bit past the tight end of the window?
I'm starting to think that the belt may be stretching more than spec when it gets hot...is that common?
I believe it's a Gates.
I'm starting to think that the belt may be stretching more than spec when it gets hot...is that common?
I believe it's a Gates.
#44
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#45