IHADAV8.com - Turbo Buick Tech, and Nonsense
Tech Area => General Buick Tech => Topic started by: Hill1430 on July 20 2023, 11:21:11 PM
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I want to thank everyone who has answered my questions over the last couple of years. I finally started my car yesterday. I was surprised it started right off. Have a couple of minor leaks to address, but overall running good. My scanmaster reads BL of 124-128 at idle depending on which time I start it. TPS is .42. Now the bad, I have Mal code 43. Bad ESC or wiring. I can get a new ESC Module from NAPA for $220. Is that the way to go, or does someone have a better suggestion? I have included a few pictures of the progress. Again, thank you all!!
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My first thought is that it's not the module. I would think it's wiring.
Try going thru the trouble shooting here.
Glad to hear the progress!
https://www.vortexbuicks-etc.com/code_43.htm
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Thanks, this gives me a place to start. Could a knock sensor installed too tight cause this?
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don't think so. That might cause false alarms but not a trouble light. Note, I did not go back and read the tree I linked :D
Looking at the tree, I would check for continuity between the knock sensor and E on the esc. A good ground at D. 8+ volts at B7 at the ecm when the key is turned to Run. And 12 volts at B when the key is in run.
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I can't get to it till Monday, but I will check those first and get back to you.
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Ok Steve, I have no continuity between E and the ESC. I have a good ground at D. I have 12 volts at B. At B7 on the ECM I am not sure how to check. What i did was try to check the back of the plug while plugged in, don't think my probe could get in there. I installed a knock sensor from Casper's which attaches to the wire at B7. I tried to get a reading at the solder joint, but was getting a reading of .067. where should I go from here?
Also I replaced the knock sensor while I had the engine out.
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E is the blue wire that runs directly to the knock sensor. Set your meter to ohms, put one probe on the connector that is E and the other one in the connector at the knock sensor. The meter should go ding and read 000. If it does, you have continuity.
B is okay as it shows power with the key on.
As far as B7 is concerned, you should have over 8 volts with the key on and the same if the engine is running. Did you try with the engine running? If you don't, I would unsolder the alarm from the wire and then see what you have.
If you changed the knock sensor, you may have to try the old one if the above checks out.
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I have to leave town for a week. I will try all of those items when I get back. I do have an unrelated question, behind the instrument cluster, upper right hand side is a 25 amp fuse, see photo. Is this related to the factory alarm system this car has?
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I checked the wire to the knock sensor and it is good. I think I might have a bad knock sensor. I found a video to bench test the sensor with it mounted in a vise hooked to a voltmeter. When you hit the vise it should give a reading over one volt, it does not. Does this sound right? If the sensor is bad, would that cause pin B7 to not show voltage?
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This version of the chart says that if tapping by the sensor does not work, then it could be a bad connector or a bad sensor if I read correctly.
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The above chart is a continuation of the trouble code checking chart.
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I have a new AC Delco knock sensor coming. As soon as it gets here I will continue diagnostic with the chart.
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All right I am an IDIOT! I rechecked all my wiring and I found that when I installed my Caspers knock guage I wired it wrong. I hooked the signal wire to the ground terminal and vice versa. So I fixed that. Still getting code 43. The only scan tool I have is the Scanmaster. So following the flow chart I do not get the rpm drop unplugging the the esc. I also don't get the rpm jump if I remove the Jumper wire at terminal E. It all seems to point to a bad esc. NAPA shows a new one, I'm ready to try that.
Do you think it would hurt the car to drive it easy until I chase this down? I want to put some miles on before I install the front clip.
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LOL
No, I don't think it will hurt to drive it easy. I am not sure it will have much power because I think it may keep the timing reduced to a low level but I am not sure about that. Give it a try and if it runs okay, it will be fine.
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Hopefully the new ESC will fix the problem.
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I am with you on that one!
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ESC Module is on back order at NAPA. Does anyone know where I might find one?
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Also Steve, I have a friend with an 87 GN. I could test if mine is good or bad by plugging into his car. If mine is in fact bad, would plugging into his car hurt it at all?
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No...that might save you some money, or prove you need to speed it.
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If his cat throws a code, will it clear when the hood esc is plugged in or does it store like newer cars?
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I would unplug the memory wire to clear everything and start fresh. I would probably install his on your car and see what happens...stil l unplugging the memory wire before restarting the car
Might want to swap ecms as well if the esc does not work
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Will do.
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Update, I checked my esc on another car and it is fine. I removed the knock gauge and no more check engine light. Sending the gauge back to have it looked at. A big Thank You for your patience and help.
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Glad it turned out that way. I was getting confused, but, at my age, I think that is my normal state. It really helps to have another car near when you are troubleshootin g