Code 24 on an 82
Thread Starter
Parrothead
Joined: May 2002
Posts: 48,231
Likes: 289
From: Margaritaville Embassy
St. Jude Donor '08-'09,'13, '14
Code 24 on an 82
the reoccurring check engine light on freeway happened again. the mechanic said he didn't have the cartridge to hook it to the computer, but he stuck some sort of gismo in the cigarette lighter and it came out with code 24, which is some sort of speed sensor input to the ecm error. my question is, how serious is this?
Thread Starter
Parrothead
Joined: May 2002
Posts: 48,231
Likes: 289
From: Margaritaville Embassy
St. Jude Donor '08-'09,'13, '14
Re: Code 24 on an 82 (terry82)
not really. and it only seems to happen when the speed is constant and the rpms steady above 1500 RPM for more than a couple minutes. I can blow down the road, max the speedo, and come back down to earth, and no code. cruise at 60 for 2 minutes and there it is
Burning Brakes
Joined: Aug 2000
Posts: 916
Likes: 0
From: Moab UT
Re: Code 24 on an 82 (Markm10431)
I've had the same problem for a while now too. I'm hoping that when I finally get her back tomorrow after 3 1/2 months that it will have reset itself....we'll see! Let me know if you find out what it is and how to get rid of it. :cheers:
Pro
Joined: May 2002
Posts: 726
Likes: 0
From: Petaluma CA
Re: Code 24 on an 82 (Markm10431)
In my 81 shop manual, figure 6E1-30, trouble code 24, vehicle speed sensor (VSS) circuit, talks about everything from loose wires to ECM which cannot be purchased. So the fact that it is intermittant is good. I guess I would start by inspecting the connections to vss, and back to ecm. Get copy of diag flow chart as mentioned above. I can get my codes by shorting diag plug below ashtray, then counting flashes. You would need a voltmeter to test these... Stevo
Thread Starter
Parrothead
Joined: May 2002
Posts: 48,231
Likes: 289
From: Margaritaville Embassy
St. Jude Donor '08-'09,'13, '14
Re: Code 24 on an 82 (Stevo)
In my 81 shop manual, figure 6E1-30, trouble code 24, vehicle speed sensor (VSS) circuit, talks about everything from loose wires to ECM which cannot be purchased. So the fact that it is intermittant is good. I guess I would start by inspecting the connections to vss, and back to ecm. Get copy of diag flow chart as mentioned above. I can get my codes by shorting diag plug below ashtray, then counting flashes. You would need a voltmeter to test these... Stevo
Pro
Joined: May 2002
Posts: 726
Likes: 0
From: Petaluma CA
Re: Code 24 on an 82 (Markm10431)
Hmmm...you have an inquisitive mind, Markm...I have found that the senser in the speedo cluster sends a series of 8 volt pulses to the ECM...but what does the ECM do with that info? Only God and Lars know. I will keep searching, but there doesn't seem to be a lot about the VSS ...I will look for the list of ECM functions and guess what it does with VSS info.
Race Director
Joined: Dec 1999
Posts: 16,945
Likes: 9
Re: Code 24 on an 82 (Stevo)
It's intermittent because the ECM won't know you're driving because the VSS isn't hooked up or not functioning. When yo drive a steady speed the TCC will lockup and because the trans is in drive the ECM will figure out you ARE driving. Then it knows it's not getting a VSS feed.
VSS is also used to reset IAC's above 35mph. On the 82 the speedo is cable driven. The VSS is a yellow box bihind the dash on the driversside. It has an optical sender/sensor on it (like 2 leds) that plugs into the back of the speedo. the light from the led is reflected on the mirror in the speedo and then oicked up again. This signal is converted by the yellow box (pulses) and sent to the ECM.
Here it is:
Marck
VSS is also used to reset IAC's above 35mph. On the 82 the speedo is cable driven. The VSS is a yellow box bihind the dash on the driversside. It has an optical sender/sensor on it (like 2 leds) that plugs into the back of the speedo. the light from the led is reflected on the mirror in the speedo and then oicked up again. This signal is converted by the yellow box (pulses) and sent to the ECM.
Here it is:
Marck
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