EO4D Complete Solenoid Pack Failure?
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Appreciate all the help I am getting here. I used the grease on my connectors before I hooked the harness back up to the transmission. Needless to say I got a code 11 in koeo mode which was nice to see. That's pretty much the good news. I replaced the window motor and now the drivers side window works. Also fixed the power lock that was on it's mount in the door. Last I put new bulbs in so now all interior lights function. Now the bad news and I read up on it a little so just thought I get a confirmation on it. I took the truck out for test drive. 4 minutes in it won't get out of 1st, also the speedometer stopped working, and prior to the trip I noticed the yellow abs light was stuck on. With a quick google search I am finding they are both likely symptoms of a bad speed sensor on the differential. I ran codes with engine on (did not do the user input part, so I understand 1 or 2 codes are from that. The codes I received are 41,65,74,77. Is it safe to assume it is the speed sensor and to replace it?
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From: Easton,Ks
The 65, 74, & the 77 were all operator error.
The 41 says the engine was running lean.
As far as the VSS (speed sensor) most just replace it but most of the time it does not fix the problem.
Most of the time it turns out to be bad wiring or plugs between the rear end and the safety wall (fire wall).
Other times it is bad bearings in the rear end.
The magnetism in the VSS sometimes looses strength and then it needs replacing but some of the after market replacements do not have strong enough magnetism in them. The after market replacements will work sometimes by disconnecting the RABS modules plug.
The 41 says the engine was running lean.
As far as the VSS (speed sensor) most just replace it but most of the time it does not fix the problem.
Most of the time it turns out to be bad wiring or plugs between the rear end and the safety wall (fire wall).
Other times it is bad bearings in the rear end.
The magnetism in the VSS sometimes looses strength and then it needs replacing but some of the after market replacements do not have strong enough magnetism in them. The after market replacements will work sometimes by disconnecting the RABS modules plug.
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I'll check the plugs for damage and pull the harness out from the truck if need be. I use the continuity function when I check my wires at each end. Should I be using the ohms function instead? Is there anything else to checking a wire and plug besides just visual damage/continuity?
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I forgot to mention I read the TRS on the transmission goes hand and hand with the VSS. Now as you pointed out Subford that at some point the transmission was replaced with one from an older model. With this transmission having the vss located on it vs on the differential where mine is located currently. Is there a chance they are not working together as they should or is the placement not relevant?
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Ran continuity on both wires coming from the differential speed sensor and it check out with 001 ohms on both wires, so no shorts I assume. I also pulled the speed sensor and visually it looks to be in good shape (Ohm it at 1550. I removed a mess of blue tooth Motorola crap as well as what looks to be some type of trailer after market module. I will pull the differential cover tommorow and put eyes on the tone ring for any damage. Other then that is there any way to test the PSOM chip behind the speedometer?
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From: Easton,Ks
I hook the PSOM to a square wave generator at 667HZ and check for 67HZ output. Also at the same time the needle will be pointing to 30MPH.
The PSOM is also hook to a 12VDC power supply at the same time.
Another test is to hold the reset button while turning on the power. The needle will swing full scale and return while reading out "E 08" and the number changes left. Let off the reset button an push it again and the CAL setting will read out.
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Well yes there is.
I hook the PSOM to a square wave generator at 667HZ and check for 67HZ output. Also at the same time the needle will be pointing to 30MPH.
The PSOM is also hook to a 12VDC power supply at the same time.
Another test is to hold the reset button while turning on the power. The needle will swing full scale and return while reading out "E 08" and the number changes left. Let off the reset button an push it again and the CAL setting will read out.
I hook the PSOM to a square wave generator at 667HZ and check for 67HZ output. Also at the same time the needle will be pointing to 30MPH.
The PSOM is also hook to a 12VDC power supply at the same time.
Another test is to hold the reset button while turning on the power. The needle will swing full scale and return while reading out "E 08" and the number changes left. Let off the reset button an push it again and the CAL setting will read out.
Fleet Owner
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From: Easton,Ks
Sounds like the odometer works and it is set up for LT235/85R E 16" tires that turn 656 Revolutions Per Mile.
Did the needle swing full scale during the test?
As for the first part a truck going 30MPH the VSS on the rear end will generate a 667HZ signal for the PSOM and the RABS module. The the PSOM will take the signal by a factor of 10 and send a 67HZ square wave signal to the PCM and the speed control module.
It will also move the needle to point at 30MPH while updating the odometer. Then it will save the odometer value and the trip value in its EEPROM chip when you turn the key off.
Each time you turn the key to run position the PSOM will read the odometer value, trip value and the CAL 984 value into its main processor from the EEPROM.
In other words it is a small computer.
To say it another way:
All functions of the PSOM module are controlled by an integrated microprocessor. It receives an input from VSS/ABS Sensor and converts signal to a standard 8,000 pulses per mile speed signal output. Signal is then provided to PCM and Speed Control Servo/Amplifier Assembly.
Did the needle swing full scale during the test?
As for the first part a truck going 30MPH the VSS on the rear end will generate a 667HZ signal for the PSOM and the RABS module. The the PSOM will take the signal by a factor of 10 and send a 67HZ square wave signal to the PCM and the speed control module.
It will also move the needle to point at 30MPH while updating the odometer. Then it will save the odometer value and the trip value in its EEPROM chip when you turn the key off.
Each time you turn the key to run position the PSOM will read the odometer value, trip value and the CAL 984 value into its main processor from the EEPROM.
In other words it is a small computer.
To say it another way:
All functions of the PSOM module are controlled by an integrated microprocessor. It receives an input from VSS/ABS Sensor and converts signal to a standard 8,000 pulses per mile speed signal output. Signal is then provided to PCM and Speed Control Servo/Amplifier Assembly.
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Well after going through and checking the wires and the vss I think I am going try swapping a psom from the junkyard. A few forum threads I have read with people having the same issue with speedometer failure with rabs light on steady as well as limp mode said they fixed with either psom replacement or psom repair be it sodering the connectors or replacement of a few common issue capacitors, diode, and w.e that disk looking black piece is. I think it's worth a $10 shot in the dark before my truck is in more pieces. Oh and the needle does go full swing.
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Alright I tried 3 junk yards with no luck of getting a psom module. So I have ordered one off ebay claiming to work. However looking at mine it looks to be in great condition. No burns or corrosion. Also even tested the diode and varisitor which seem to be functioning correctly. I also ordered a ford vss even though I doubt it will fix the issue. I will pull the differential cover and check the tone ring after I test the psom when I get it. Today I located ground 200 which is supposed to be the ground for the psom, vss, rab, etc. All wires are connected so it's not a ground being disconnected.
also what is the last connector on the right I can't seem to find it in my evsm book. As you can see it's disconnected...
also what is the last connector on the right I can't seem to find it in my evsm book. As you can see it's disconnected...
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