Codes 63 & 98
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Code 63 - Throttle Position Sensor (TPS) signal too low TPS. Vref missing (5 volt reference voltage supplied by the computer), bad connections or damaged wiring, TPS sensor failed, TPS sensor way out of adjustment. Use a DVM to check for 5 volts on the Orange wire. If it is missing, look for +5 volts at the Orange wire on the EGR or MAP sensor located on the firewall near the center of the car.
Try this... Currently there is some dispute about setting it at .99 volts but anything less is probably OK. All you need is less than 1.0 volt at idle and more than 4.25 at Wide Open Throttle (WOT). You'll need a Digital Voltmeter (DVM) to do the job.
Here’s a TPS tip I got from NoGo50…
When you installed the sensor make sure you place it on the peg right and then tighten it down properly. Loosen the back screw a tiny bit so the sensor can pivot and loosen the front screw enough so you can move it just a little in very small increments. I wouldn’t try to adjust it using marks. Set it at .97v-.99v, the closer to .99v the better. Just don’t go over .99, or you upset the fuel calibration and idle quality will suffer.
(copied from MustangMax, Glendale AZ)
1. Always adjust the TPS and Idle with the engine at operating temp. Dive it around for a bit if you can and get it nice and warm.
2. When you probe the leads of the TPS, do not use an engine ground, put the ground probe into the lead of the TPS. You should be connecting both meter probes to the TPS and not one to the TPS and the other to ground.
3. Always reset the computer whenever you adjust the TPS or clean/change any sensors. I just pull the battery lead for 10 minutes.
4. Check the procedure for your year, on my 90 I have to turn the idle screw until it just touches the tab, then insert a .010 feeler gauge and give it about one more turn. Then you adjust the TPS voltage to .98v, reset the computer. Start it up, if the idle is to low then turn the screw in until it is just right, then readjust the TPS voltage to .98v and reset the computer and start it up. The key is to adjust the TPS voltage and reset the computer whenever the idle screw is changed.
Code 98 - basic computer internal tests not passed before it started processing the request to dump codes. Do a Key On Engine Off test before starting the engine. Wait until you see the 11 flash before pressing any buttons if you have a hand operated scanner. The computer is operating in Limp mode, so fix any codes it dumps prior to doing anything else.
Try this... Currently there is some dispute about setting it at .99 volts but anything less is probably OK. All you need is less than 1.0 volt at idle and more than 4.25 at Wide Open Throttle (WOT). You'll need a Digital Voltmeter (DVM) to do the job.
Here’s a TPS tip I got from NoGo50…
When you installed the sensor make sure you place it on the peg right and then tighten it down properly. Loosen the back screw a tiny bit so the sensor can pivot and loosen the front screw enough so you can move it just a little in very small increments. I wouldn’t try to adjust it using marks. Set it at .97v-.99v, the closer to .99v the better. Just don’t go over .99, or you upset the fuel calibration and idle quality will suffer.
(copied from MustangMax, Glendale AZ)
1. Always adjust the TPS and Idle with the engine at operating temp. Dive it around for a bit if you can and get it nice and warm.
2. When you probe the leads of the TPS, do not use an engine ground, put the ground probe into the lead of the TPS. You should be connecting both meter probes to the TPS and not one to the TPS and the other to ground.
3. Always reset the computer whenever you adjust the TPS or clean/change any sensors. I just pull the battery lead for 10 minutes.
4. Check the procedure for your year, on my 90 I have to turn the idle screw until it just touches the tab, then insert a .010 feeler gauge and give it about one more turn. Then you adjust the TPS voltage to .98v, reset the computer. Start it up, if the idle is to low then turn the screw in until it is just right, then readjust the TPS voltage to .98v and reset the computer and start it up. The key is to adjust the TPS voltage and reset the computer whenever the idle screw is changed.
Code 98 - basic computer internal tests not passed before it started processing the request to dump codes. Do a Key On Engine Off test before starting the engine. Wait until you see the 11 flash before pressing any buttons if you have a hand operated scanner. The computer is operating in Limp mode, so fix any codes it dumps prior to doing anything else.
well looking at my TPS it looks like it broke. one of the pieces that touch the thing in the TB to tell how much gas your giving chipped a piece off of the corner.
but it does look like is turning when i rev the engine from the thing on the TB. but i know someone was messing with my idle screw right before i got this code.
so i either got this code cause it the corner of the thing in the TPS broke off or because my brother inlaw was messing with my idle screw or the combination of both.
so if i just buy a new TPS would i have to mess with the voltage with the new one. im guessing ill have too if the idle screw got messed up. even tho it idles pretty damn good right now. better then ever.
but i need to make sure everything checks out ok on it cause i have to get it inspected and the emissions done on it soon.
and im a little confused on code 98. when i got that code it dint do it normal thing when i go to check the codes. the car just reved to 2000 rpm for the whole "test" and just flashed 9 flashes and then 8 flashes and then the flashes for 63. no other flashes in the begining like it usually does.
so 98 isnt a big deal?? it just dint do its normal process to check the codes as it always does for KOER self test.
and whats a good way to reset the computer. take off the neg. battery cable for like 10-20 mins. hook the neg. cable back on and then whats a good way after that. i hear alot of different things that people do.
BTW mine is a 92 5.0
but it does look like is turning when i rev the engine from the thing on the TB. but i know someone was messing with my idle screw right before i got this code.
so i either got this code cause it the corner of the thing in the TPS broke off or because my brother inlaw was messing with my idle screw or the combination of both.
so if i just buy a new TPS would i have to mess with the voltage with the new one. im guessing ill have too if the idle screw got messed up. even tho it idles pretty damn good right now. better then ever.
but i need to make sure everything checks out ok on it cause i have to get it inspected and the emissions done on it soon.
and im a little confused on code 98. when i got that code it dint do it normal thing when i go to check the codes. the car just reved to 2000 rpm for the whole "test" and just flashed 9 flashes and then 8 flashes and then the flashes for 63. no other flashes in the begining like it usually does.
so 98 isnt a big deal?? it just dint do its normal process to check the codes as it always does for KOER self test.
and whats a good way to reset the computer. take off the neg. battery cable for like 10-20 mins. hook the neg. cable back on and then whats a good way after that. i hear alot of different things that people do.
BTW mine is a 92 5.0
The 98 code means you should let the computer dump all the stored codes prior to starting the engine and dumping the running codes. That insures that it has completed all the preliminary diagnostic tests and is ready to do the engine running tests.
if i get what your saying correctly. i should let the computer dump the codes before i let it run.
but i did the proceder right i think. i warmed up the car warm up to normal operating temps. and then turned it off and did the KOEO test first and just got code 63 and then went and did the KOER test and just got 98 and then 63.
im checking the codes with a wire and the engine light flashes.
am i missing something here. cause when i did the KOER test it never did any test. it just reved to 2000 rpm and flashed the 98 and 63. not what it normally does to test everything.
so if i get the code 63 figured out and it working again and get System pass for KOEO i wont get the 98 code for KOER or the 63 for KOER
but i did the proceder right i think. i warmed up the car warm up to normal operating temps. and then turned it off and did the KOEO test first and just got code 63 and then went and did the KOER test and just got 98 and then 63.
im checking the codes with a wire and the engine light flashes.
am i missing something here. cause when i did the KOER test it never did any test. it just reved to 2000 rpm and flashed the 98 and 63. not what it normally does to test everything.
so if i get the code 63 figured out and it working again and get System pass for KOEO i wont get the 98 code for KOER or the 63 for KOER
