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why i hate automatic transmissions...

Riddle_3d

Riddle_3d

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Montgomery City, MO
so, after dealing with the random limp mode on the 95 still, i got the '93 back together yesterday, rebuilt transmission (balancer cracked bellhousing) and motor. took it out last night, wouldnt shift. moved TPS, wont shift. cleaned all connections and made sure they were tight, wont shift. added extra grounds and cleaned existing ones, wont shift. checked codes, code 12 "no codes present." no manual 1st or 2nd gear, nothing. it goes forwards and backwards, thats it really. what else can i do? speedometer works perfectly too.
 
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A scan tool is your friend. Without knowing what the PCM is seeing for sensor readings it is mostly guess work. I n the tranny section a good method of narrowing down was given. Unplug the main electrical connector. The tranny will go to full hydraulic pressure. That would eliminate the mechanical aspect. Then the problem is electrical.
 
22 - Accelerator Pedal Position (APP) 1 Circuit Low

81 - 2-3 Shift Solenoid Circuit Fault

If I had to guess, I'd say your code 22 is causing the code 81.

The PCM needs to see the throttle position sensor in order to shift the trans correctly.

Bad news is, an APP is not cheap.....
 
great white said:
22 - Accelerator Pedal Position (APP) 1 Circuit Low

81 - 2-3 Shift Solenoid Circuit Fault

If I had to guess, I'd say your code 22 is causing the code 81.

The PCM needs to see the throttle position sensor in order to shift the trans correctly.

Bad news is, an APP is not cheap.....
Click to expand...

This is on a 93. Mechanical fuel injection. No APP. Codes for a 93 are different from 94-95
 
The 22 is just a TPS input problem instead of APP, which is likely the problem still.

TPS isnt getting to TCM. This is why the APP may be more robust because its 2 sensors vice the one, and it will run on any 2 of the 3 with no ill effects.
 
it was rebuilt by a reputable guy in Fayette, MO. im going to get a TPS tomorrow (cleaning out the bank account for me, so no scan tool in the near future) and that will eliminate the 81 code possibly also?
 
bk95td said:
This is on a 93. Mechanical fuel injection. No APP. Codes for a 93 are different from 94-95
Click to expand...

Same dealeo then. code 22 is for a TPS sensor, which is the function of an APP (well, that and the throttle stepper).

Most likely the problem with the shifting.

No TPS signal, no shifty shifty....

If cash is tight, just go grab one from a junkyard.

That way, you're not out 50 odd bucks if it doesn't fix the problem.

Most places won't take electrical components back once they've been installed....
 
The problem ends up being that you have no pressure increase to support the shift. Its kind of like a Ford AOD tranny TV cable. The cable on the throttle actually controlled line pressure, it wasnt a kickdown linkage. So if no cable or loose cable no pressure, no shift, and you burn up a tranny if getting on it hard. I have seen this a lot with Ford Demolition Derby cars. We have 4 of them, and when I thought I had it tight apparantly the tranny didnt. Guys think they disabled over 1st gear by limiting the linkage movement, and then their tranny nukes on them at WOT. I try to explain to them about the TV cable not being a kickdown.

Same thing is happening to your tranny, the TCM sees that your speed is way beyond what it should be in 1st gear, with the input and output speed its getting. It wants to shift but not enough line pressure to make it happen.
 
well, i was walking on thin ice with this one anyways. it was installed wrong, it popped backwards, i took it off, corrected it, it moves with the throttle, but i guess without signal. ive had bad luck with used electronics, so im going to get a new one and be done with it
 
Plug a voltmeter via back probe of the TPS and see what it is doing. You want .45 to .5v at idle position and over 4v at WOT. The other two wires are 5v and ground. This is a $200 part. Your adjustment of it appears to have caused the out of range TPS code. Likely from idle voltage too low.

Check the two separate speed sensor wires/plugs on the transmission connectors as the insulation tends to fall off and short out at this age.

The lack of manual 1 and 2 gears means adjustment of the shift linkage is bad or something is FUBAR on the rebuild.
 
WarWagon said:
Plug a voltmeter via back probe of the TPS and see what it is doing. You want .45 to .5v at idle position and over 4v at WOT. The other two wires are 5v and ground. This is a $200 part. Your adjustment of it appears to have caused the out of range TPS code. Likely from idle voltage too low.

Check the two separate speed sensor wires/plugs on the transmission connectors as the insulation tends to fall off and short out at this age.

The lack of manual 1 and 2 gears means adjustment of the shift linkage is bad or something is FUBAR on the rebuild.
Click to expand...

Great advice!

Can't believe I missed recommending back probing the sensor before replacement.....D'oh!

I must e getting old.......:rolleyes5:
 
It has been a while since I have had a 6.5 but isn't there a crank sensor back on the top of the oil pump drive? (where the distributor is on a gasser) I remember on my 93 it was messed up and the transmission didn't shift properly.
 
WarWagon said:
Plug a voltmeter via back probe of the TPS and see what it is doing. You want .45 to .5v at idle position and over 4v at WOT. The other two wires are 5v and ground. This is a $200 part. Your adjustment of it appears to have caused the out of range TPS code. Likely from idle voltage too low.

Check the two separate speed sensor wires/plugs on the transmission connectors as the insulation tends to fall off and short out at this age.

The lack of manual 1 and 2 gears means adjustment of the shift linkage is bad or something is FUBAR on the rebuild.
Click to expand...

what do you mean by "back probe"? im electronically retarded, does this just mean checking voltage at the connetor? and is the speed sensor the one for the speedometer on the tail shaft of the transfer case? the speedometer works perfect also. it also goes into every gear, but when you move it up from one to two, it never shifts up. my '95 looses manual gears in limp mode, so thats what i figured was happening.
 
Riddle_3d said:
what do you mean by "back probe"? im electronically retarded, does this just mean checking voltage at the connetor?
Click to expand...

Pretty much. You need to make/use a thin wire on the end of you multimeter and go into the back side of the connector while it is attached to the TPS. Or, you can pierce the wires with the multimeter probe, but I avoid this if possible as it can lead to corrosion issues.

Should go something like this:

Black - ground (at least for the TPS circuit - may not be a vehicle/chassis ground).

Gray - this is the 5 vdc regulated reference voltage generated by the TCM.

Blue - this is the variable output of the TPS. Should about 0.5 vdc at idle and 4.5 vdc at full pedal.

(wire colors may be wrong, check it out yourself first)

You're looking to verify that the TPS is putting out the 0-5ish volts that it should be, dependent on throttle position.

WW is right, you may just be way out of adjustment since you moved the sensor. I sounded like you took the sensor off, the spring snapped the sensor back and you bolted it back on. Is this true?

If so, you've probably got the sensor installed wrong. The voltage check will tell you if it is. If you don't see the .5 v at idle position, you need to rotate the TPS (if the holes are slotted) until you do.

While I can't say for sure with a 93 TPS, most are "loaded" against the throttle shaft by an internal spring. They usually need to be installed and turned slightly to load the spring and set the idle voltage.

Check it out though, like I said I'm not sure about the specifics on a 93....

Riddle_3d said:
it also goes into every gear, but when you move it up from one to two, it never shifts up. my '95 looses manual gears in limp mode, so thats what i figured was happening.
Click to expand...

So, are you saying it shifts when driving but not when you move the shifter manually?

Not sure what you're saying there....
 
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bison said:
Did you delete the codes.?
Once a code is set,the tranny stays in limp mode no matter what till you remove it.
Click to expand...

In my experience Key off key on resets the trans out of limp mode. This usually locks out overdrive and TCC lock. The trans heats up without TCC lockup. This was with a blown up overdrive sprag and then a misadjusted TPS on my 1993. Your milage may vary.

I back probe with straight pins through the side of the wires going into the connector. The connection is made through the rubber seal and in the connector.

Down shift all the way to 1st gear manually and count the shifts. You should have compression braking in 3rd, 2nd, and 1st. Accelerat and make sure each gear works. If not back to the trans shop - the compression braking is different then acceleration as far as broken parts - you can have acceleration in 2nd but no braking for example.
 
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