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lean burn obd1
https://slantsix.org/forum/viewtopic.php?t=34707		 Page 1 of 4
Author:  Mister_Perkins [ Sat Apr 04, 2009 2:18 pm ]
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check ECM make sure your not throwing any codes. !
Not possible. Even if this is a lean burn engine, the computer does not have the capability of setting/storing/accesing codes. No Mopar slant six computer has this ability. The lean burn is a dumb computer.
Actually it does. Why is there an OBD 1 Connector harness on the firewall then? I connected my truck with an OBDI scan tool and got code 91, which is vaccume transistor. Dont tell someone that they cant do something unless you know for sure.

On 1986 -87 models, test continuity of wiring in each circuit indicated by fault codes or in other circuit tests for logic and power module terminal identification. On 1988-89 models, test continuity of wiring in each circuit indicated by fault codes or in other circuit tests SMEC terminal identification.
Author:  Charrlie_S [ Sat Apr 04, 2009 4:22 pm ]
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Quote:
Quote:
Quote:
check ECM make sure your not throwing any codes. !
Not possible. Even if this is a lean burn engine, the computer does not have the capability of setting/storing/accesing codes. No Mopar slant six computer has this ability. The lean burn is a dumb computer.
Actually it does. Why is there an OBD 1 Connector harness on the firewall then? I connected my truck with an OBDI scan tool and got code 91, which is vaccume transistor. Dont tell someone that they cant do something unless you know for sure.

.
I thought I did know for sure. I would like to contine this part of the discusion, in another thread. What year and model/engine is your truck.
PS, I am a ASE certified master tech, but I don't know everthing, and am open to you showing me I am wrong.

When you reply, I can move this part of the thread.
Author:  Mister_Perkins [ Sun Apr 05, 2009 2:20 pm ]
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87 Dodge D150, 225 /6. I know my truck has an OBD I Connector harness on it. I can even take a picture of us hooking it up and running the scan tool if you would like.
Author:  Reed [ Sun Apr 05, 2009 2:52 pm ]
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87 Dodge D150, 225 /6. I know my truck has an OBD I Connector harness on it. I can even take a picture of us hooking it up and running the scan tool if you would like.
Please do. I also thought that the lean-burn computers never got OBD capabilities, not that I think it is worth keeping the lean burn just to have OBD....
Author:  Charrlie_S [ Sun Apr 05, 2009 3:51 pm ]
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I would like to see a picture, also. If memory serves, there is a connector in the engine compartment, but is is not an OBD1 connector, it is an assemply line test connector.
Author:  Reed [ Sun Apr 05, 2009 4:07 pm ]
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I concur with Charlie. I have worked on several mid 80s trucks and vans that had the diagnostic connector under the hood, but it was only for things like battery voltage, alternator output, a tach connection, etc... Nothing as fancy as error codes or a vacuum reading.
Author:  Charrlie_S [ Sun Apr 05, 2009 4:21 pm ]
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Just went out to the shop, and got my Snap-on scanner/reference manual.
This is a quote;
"The chrysler vehicles listed either do not have electronic engine control systems, or they have systems without self-diagnostic capabilities. They will not communicate with a scan tool.
Pre-1983--all models
1983-84--all carbureted engines
1985-87--2.6 liter, 4 cyl car Mitsubishi engine with Mitsubishi control system
1983-91--all rear wheeldrive passenger cars (V-8 and 6-cyl)
1983-91--all diesel powered vehicles
1991------Jeep grand wagoneer & eagle summit
pre-91----all jeep, eagle, & amc-renault vehicles.

This chart does not list 1983-91 trucks (does list 83-91 rear drive cars), but The ECM is basically the same, on the carb slant six, and v-8.

I don't work on that many trucks from that era, so I could be wrong, but at this time, I still say the truks with the lean burn will not set codes. Please show me a picture of the diagnostic connector on your truck.
Also if possible, could you post the 1st 10 digits of your VIN?
Author:  Mister_Perkins [ Sun Apr 05, 2009 4:45 pm ]
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sure. I'll get some pictures tomorrow of the truck connected to the scan tool, and take a picture of the book too that tells what all of the codes are.
Author:  Matt Cramer [ Mon Apr 06, 2009 11:13 am ]
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87 Dodge D150, 225 /6. I know my truck has an OBD I Connector harness on it. I can even take a picture of us hooking it up and running the scan tool if you would like.
Did a little bit of searching on Alldata - the information there implies that there was a version of the Lean Burn computer made for three years on the slant six that was not a true OBD-I system but was capable of storing trouble codes. This oddball only showed up in '85 through '87; earlier ones quite definitely are not able to store codes. It is possible they accidentally copied over information from a V8, but oddly they don't show the same info for V8s from that year.
Author:  Reed [ Mon Apr 06, 2009 11:21 am ]
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The plot thickens. I am very interested to see those pictures and learn more info about this. I have never before heard of a lean-burn system having any sort of OBD capabilities.
Author:  Mister_Perkins [ Mon Apr 06, 2009 2:29 pm ]
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well i didnt get a picture of it today, but I will tomorrow. We got slammed at the shop. For sure tomorrow though. Until then. I think its funny that you guys don't think that the 87 D150 has cabability to store trouble codes. On my truck it does store the codes. At first code 91 showed up on mine and i thought it was the O2 sensor because that was what the codes said, but after further looking it was for the 318 V8. I turned the page and code 91 showed up for /6 as vaccume transistor. I'll get you guys a picture tomorrow for sure though.
Author:  00spy [ Mon Apr 06, 2009 2:52 pm ]
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I found a picture of it


Image
:lol:





Dave
Author:  Matt Cramer [ Mon Apr 06, 2009 5:02 pm ]
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Alldata called code 91 a problem with a "oxygen solenoid," a rather confusing line there.

I believe the Clifford short manifold came in both heated and unheated versions. The one on my Dart is an unheated version.
Author:  Mister_Perkins [ Mon Apr 06, 2009 5:58 pm ]
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The oxygen sensor was for the 318. Code 91 is oxygen sensor for the 318, code 91 is vaccume transistor for the 225. My truck does not have an O2 sensor
Author:  Charrlie_S [ Mon Apr 06, 2009 6:20 pm ]
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The plot thickens. M_P, what brand scanner are you using?
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