QuestionQUESTION: Good Morning Roland,
Ran the key test: - = pause Start 1-2-2-4-1-4-2-3-2-2-5-6 then solid check engine light..... What do you make of this?
ANSWER: Hi Bob,
Hi Bob,
The codes are as follows:
12 battery disconnected in the past 50-100 key cycles, not a problem unless you haven't done that
24 throttle position sensor signal voltage too high or too low
14 manifold absolute pressure sensor signal voltage too high or too low
23 not a valid code
22 engine coolant temp sensor signal too high or too low
56 not a valid code, could that be a 55 which I would expect to be the last code?
All the sensors issues if correct would explain the poor performance of the engine. I would begin by looking over all the harnesses involved in those sensors to see if you can find a place where the wires' insulation has melted and shorted the wires to one another. Particularly I would look on the rear side of the valve cover where the exhaust manifold sits just below a large number of wires that are involved with these sensors and so the heat can cause over time a melting situation.
Because of there being 2 codes that are not valid I would encourage you to do the readout again, and maybe again, until you are certain of an accurate count.
After you check the wire conditions you would want to check the wires connections to the engine controller using your ohmmmeter and also check them to make sure none are electrically shorted together. The MAP and the TPS sensors both use the same reference voltage wire, wihich if shorted to ground for example, would cause their codes. It would be a waste of money to start buying new sensors before that is done.
Roland
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QUESTION: I will follow your info, may take awhile.
Since I am new to the ohm meter; would you please give me the multimeter dial settings and what readings I am looking for? Thank you Roland
Bob
ANSWER: You would be looking for 0 ohm or there about when two wires that you are testing for a short circuit between them, and an infinite ohm (often a reading of "2" on the readout which means more that 2, 20, 200 whatever dial setting you are using) if the wires are independent of one another. For that reason it would be good to disconnect all the sensors you suspect as well as the multi-wire plug at the engine controller when testing the wires. But if a device of some sort is connected between the wires then any reading is possible. Also note that you would want to change the setting if you get a '2' on the 2k scale, to be sure it is also a '2' on the 20k and 200k scales to be sure it is truly an infinite reading.
I now find that in '96 that a different 4 cyl engine was used for the first time, this one from AMC. It has multipoint fuel injection, not a throttle body injector, so I don't have the details about that engine as I don't have truck manuals.
Did you try recounting the flashes?
Roland
PS Please do all the observations I have suggeested before asking another question as I can't devote so much time as we have in the past 2 days to any individual questioner (9 questions answered in the past 2 days). Thank you
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QUESTION: I recounted 5x results remain the same: 12,24,14,23,22,56.
AnswerThe 56 is the only one that is strange. I have to believe it is actually 55.
The 23 I did find to be another sensor being off-value, the intake air temp sensor.
With so many sensors involved here I do believe there is a short in a common voltage wire used by some of those sensors and/or melted wires that happen to be at a place where all are impacted. So you will want to look over all the harnesses associated with the sensors in and around the intake manifold and then do some voltage testing. As I said however, I don't have the wiring diagram for the truck.
