Ok to start er off I have a 99 4.0 auto
Now my problems first started when my headlights quit working all of a sudden. I have aftermarket ebay projectors and h4 bulbs. Then my power door locks stopped working. Then when leaving a long trip of wheeling, I drove my jeep all day, and just getting back on the highway my jeep started to cut out and want to bog and die the more throttle i gave it. I limped it home(which was hell) when it would really want to die like on steep hills I had to pull over and restart my jeep. It would let me drive like I stole it for a little while.. then back to same old 1/4 throttle babying it all the way home. SO it threw a CEL and I checked it when I got home. p0171 Bank sensor lean. OK so I knew where to start and I started with the TPS. I was getting 5.14v input and .14-.15v output. That was with my Klein digital multimeter.. I start it up to test it at idle and my jeep threw a lot more codes. p0300 multiple misfire p0301 p0303p0306 also threw a code for High voltage TPS sensor and LOW voltage on the TPS.. So I then change the TPS with a spare I had sitting in my outdoor shed. It is an original from my 99 that I replaced when troubleshooting a misfire. I test the TPS with the multimeter and I got the same results as before.. Totally stumped I cleared the codes and took it around the block.. Same results as before. CEL came on TPS voltage too high and too low only this time.. I have a nice Actron OBDII scanner with live data that I can also see the TPS voltages and lots of other things if you guys can recommend more testing.

I am looking into it possibly being a ECU/PCM issue.. Anybody experience problems like this?
I need some fast help dis is my baby gurl!!

 

Before condemning the PCM, take a good look at cables, connectors and grounds.
Battery and alternator good? Voltage out of spec causes all sorts of oddball problems too.

 

Battery tested 12.5v it's an optima yellow top bout 2 1/2 years old

 

What does the voltage (at the battery terminals) read with the engine running?

I'd give some thought to looking at the grounding points, it's a common cause of trouble.

 

Yeah it very well could be a ground. Besides the one on the driver fender well and the back of te valve cover where is there more grounds?

 

Read this today.
TPS CODE P0123 WILL NOT CLEAR COMPLAINT: CAUSE: CORRECTION: A late model Jeep with a 2.5 or 4.0 liter engine and the AW4 transmission comes in with the “MIL” Lamp illuminated and a complaint of late shifts. A scan reveals a code P0123, “TPS Voltage High”, is stored. The scan tools data list indicates that the TPS signal wire voltage is at 5.0 volts at closed throttle, and then ranges up to 11.5 volts. A backup check of the TPS signal wire (usually is an Orange/Dk Blue wire), shows 5.7 volts at closed throttle, with a similar rise in voltage as the throttle is opened. A check of the TPS 5 volt supply and ground circuit prove that both of these circuits are good. A check of the TPS signal wire with the TPS disconnected shows the same 5.7 volts. The technician now begins an inspection of the wiring between the TPS and the PCM and TCM to no avail. A replacement TPS does not cure the problem, neither does replacement of the PCM or TCM. The Switch Sense circuit in the Clockspring in the steering wheel hub has shorted to battery voltage from the horn button circuit. When the Switch Sense Circuit shorts to the 12 volt HORN circuit the TPS signal voltage is driven high and remains there as shown in Figure 1. This is because the 5 volt reference voltage used by the Cruise “Switch Sense” circuit and the TPS are shared inside the PCM. Replace the Clockspring assembly. Once the Clockspring has been replaced, be sure to check the sensor 5volt reference voltage at the PCM to insure that circuit has not been damaged by the short to power. Also check the TPS signal range to insure the TPS has not been fried.

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My airbag light does go on and off all the time. I noticed I have aftermarket bosch horns on the front.. don't know if the PO installed them or what. My cruise does work… or at least before these problems.. Im thinking my headlights door locks tps airbag light and horns might all be related to the clock spring. Fortunately I have a DD cherokee chief now and I can have down time for the 99

 

:/ I really good use some guidance with this issue