codes 122,334,631 Computer problems
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Freshman User
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codes 122,334,631 Computer problems
Hi all on this forum.
Been told by the guys on vans that you maybe able to shed some light on my problems.
Vehicle is a e150 93 5.8 efi.
Running really rough, starts first time but then cuts out, really difficult to restart and keep running, gear changes rough.
Pulled the codes 122, 334, and 631. The guys on vans told me what the problems were and I did some more checking.
Put 5 hours in and still none the wiser.
The actual TPS is fine, took it off and ran tests on it, works fine.
Of the 3 wires going into it, the voltage readings are as follows
vref-5.00v.
sig rtn-0.04v.
tps-0.04v.
If i move the thottle the readings do not change. I followed the sig rtn and tps wires back to the computer and took readings from there and they were the same. As a matter of interest I took readings from the egr valve and they were the same as the readings on the TPS sensor.
Should one of the wires be to earth, I don't understand this at all and really need some help. Please give me any suggestions that you can think of that might help (already thought of the box of matches but I love her too much).
Best regards
Allan
Been told by the guys on vans that you maybe able to shed some light on my problems.
Vehicle is a e150 93 5.8 efi.
Running really rough, starts first time but then cuts out, really difficult to restart and keep running, gear changes rough.
Pulled the codes 122, 334, and 631. The guys on vans told me what the problems were and I did some more checking.
Put 5 hours in and still none the wiser.
The actual TPS is fine, took it off and ran tests on it, works fine.
Of the 3 wires going into it, the voltage readings are as follows
vref-5.00v.
sig rtn-0.04v.
tps-0.04v.
If i move the thottle the readings do not change. I followed the sig rtn and tps wires back to the computer and took readings from there and they were the same. As a matter of interest I took readings from the egr valve and they were the same as the readings on the TPS sensor.
Should one of the wires be to earth, I don't understand this at all and really need some help. Please give me any suggestions that you can think of that might help (already thought of the box of matches but I love her too much).
Best regards
Allan
Fleet Owner
Joined: Oct 2005
Posts: 20,789
Likes: 1,753
From: Kentucky
You need to measure the TPS between the Signal and Signal Return. Signal Return in many cases is not at ground potential. The Signal output from the TPS should measure above ~.4 VDC to .9 VDC when closed then increase to ~4.50 VDC at Wide Open Throttle.
Use this for reference at Ford Fuel Injection dot Com: Throttle Position Sensor (TPS)
Use this for reference at Ford Fuel Injection dot Com: Throttle Position Sensor (TPS)
Thread Starter
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Freshman User
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Thanks for the reply. There is no voltage when checked between those two, and this does not change when I open the throttle. I can only think there is a short somewhere between the two or they are earthing what do you think?
Best regards
Allan
Best regards
Allan
Fleet Owner
Joined: Oct 2005
Posts: 20,789
Likes: 1,753
From: Kentucky
If you disconnect the TPS, set your meter to measure ohms, connect it to the TPS itself, move the throttle, you should see a a change in resistance. If not, the TPS is bad. Start with the easy stuff first...
Fleet Owner
Joined: Oct 2005
Posts: 20,789
Likes: 1,753
From: Kentucky
Then your TPS is defying the laws of electricity. If you have 5V as your reference then measure between the signal output and Signal Return you should see a voltage swing from roughly .4 VDC at closed throttle to 4.5 VDC at wide open throttle. Did you use the link I posted earlier for reference on how the circuit works and how to measure it?
Thread Starter
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Freshman User
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Yes used the link, back probed the two pins, could they be earthing somewhere or being affected by the ref going to other sensors mainly the egr? What do you think?
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Fleet Owner
Joined: Oct 2005
Posts: 20,789
Likes: 1,753
From: Kentucky
I suppose the TPS output could be shorted to ground or Signal Return someplace. Pull the connector to the TPS, set your meter to Ohms, measure between the signal and signal return pins with the key off. I would expect an open or very high resistance. If they are shorted together, there is the problem.
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