1987 - 1996 F150 & Larger F-Series Trucks1987 - 1996 Ford F-150, F-250, F-350 and larger pickups - including the 1997 heavy-duty F250/F350+ trucks
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654: MLP sensor not in park position
668:Transmission Manual Lever Position Sensor circuit open
Sounds like a problem with the wiring/plugs under the truck.
Test the pins from the MLP Sensor (or TR sensor) at the computer plug (46 & 30) for the right resistance on each of its wires (preferably with a BOB). Have someone shake the wires under the truck while you test them.
MLP sensor wiring:
MLP sensor test:
You might want to use this tool to position the MLP sensor sensor if the readings are not right.
Ok after replacing the speed sensor with a ford OEM sensor that I bought a while back, the speedometer shows a stable speed it no longer jumps around, that problem is resplved but still having the hard shift.
Now I am trying to test the MLP sensor but not sure what 46 & 30 relate to. Sorry you may have to get to more of a basic level.
I appreciate your help SUBFORD
I also decided to see if I could find that tool you showed since I have seen it on a few other pages and ford told me to call MAC tools and they told me they could not get it. I went to national auto parts and after about 30min of searching the guy found that they can get it but it’s $100 and 35$ to get it shipped.
46 & 30 are the pin numbers at the PCM computer plug shown in the diagrams above.
If the ohm readings check out you may not need the tool.
Some auto parts stores may loan (rent) you the tool also.
It is just a strait line alignment tool for three holes.
If you would like to make one out of flat stock I could send you the specifications of the tool.
Ok I tested the ohms for the MLP SENSOR at the PCM plug and all tested fine the rating of each gear was in the middle of each threshold. Any other suggestions or thoughts? You would think that by now we would have run across something.
If every thing test good I can only tell you what the Ford Shop Manual says for those codes.
DTC 654 indicate the gear selector was not in Park during Self-Test.
Open or short in harness circuits.
Damaged MLP sensor.
DTC 668 - PERFORM DRIVE CYCLE TEST
Run Key On Engine Off (KOEO) Self-Test and record all Continuous Memory DTCs displayed.
Clear Continuous Memory (refer to Quick Test Appendix, «Section 5A»).
4R70W, AODE, CD4E, E4OD and AX4S-3.2L SHO Drive Cycle:
– Gear position in DRIVE range, press the Transmission Control Switch (TCS) (the Transmission Control Indicator (TCIL) should light) and moderately accelerate from stop to 40 mph. This will allow the transmission to shift into third gear. Hold speed and throttle opening steady for a minimum of 15 seconds (30 seconds for altitudes above 4000 feet).
– Press TCS (the TCIL should turn off) and accelerate from 40 mph to 50 mph. This will allow the transmission to shift into fourth gear. Hold speed and throttle steady for a minimum of 15 seconds.
– With transmission in fourth gear and maintaining steady speed and throttle opening, lightly apply and release brake (to operate stop lamps). Then hold speed and throttle steady for at least an additional five seconds.
– Brake to a stop and remain stopped for a minimum of 20 seconds with transmission in drive. Repeat drive cycle at least five times.
Rerun KOEO Self-Test and record all Continuous Memory DTCs.
To clear the codes as you have changed a sensor unhook the NEG post of the battery for about 30 minutes. This will enable the PCM to start a re-learn cycle and maybe some driveability problems for 10 miles..
But this will also set a code of memory fail in the PCM.
So clear that code by grounding the STI wire near the EEC Self-Test Plug and turn on the key. When the MIL on the dash starts to flash remove the ground from the STI wire before turning the key off. This will clear all codes.
Only do the battery disconnect part when you change a sensor to clear codes.
At other times use the STI wire to clear codes.
The indicator is just for information to the driver and has no bearing on the transmissions operation.
The only things in the column that can effect the transmission are the wire from the switch on the end of the manual lever and the two T30 screws at the bottom that come loose all the time.
Now when I was under my truck I did notice that the two wires on the MLP sensor 359 and 199 that are for the transmission circuit appeared to be pushed up and I pushed them back down. So I will try and rest the codes and see if there was a connection issue in the plug it’s self. I did replace the plug when I replaced the MLP Sensor but the new plug used the old wire connectors.
So it looks like I have defective connectors in my MLP plug, I did replace the plug but the new plug used the old connectors. I pulled the plug apart last night when I was testing the OHMS at the PCM plug and pushed down on 359 and 199. I then drove 15 miles today to get some lumber and even with a large load it shifted wonderfully. I just picked up a replacement plug and I am going to install it tonight I am taking the truck camping over the weekend so we will see if the replacement plug fixes the issue once and for all. I will update this tread when I get back on Wednesday. Thank again everyone and a special thanks to subford.
Well over the holiday weekend the truck went back to its old self again and started doing the hard shifting again. I even decided to replace the plug going to the passenger side of the transmishion to the solenoids. Still having the same problems. Could the PCM be going out? There is a local junk yard that will sell me the PCM for 25$.
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