Recent content by rdomeck

  1. R

    1999 7.4 Low sensor voltage P1122 P0122

    I'm glad a got it too. I missed one plug in at the firewall on the left side keeping the fuel gauge from working. Not bad for all that work. I guess I had a few more hours in this. Maybe 10 hours total. Now I can start to get the rest of the work done to this. Drove it a hundred miles...
  2. R

    1999 7.4 Low sensor voltage P1122 P0122

    It's fixed.... I pulled the harness and found the 5V reference wire for the EGR circuit was shorting to ground. That circuit is also the 5V for a couple of other sensors. I suspect that they are al fed from the same point inside the ECM making every sensor not do its job. It is very small...
  3. R

    1999 7.4 Low sensor voltage P1122 P0122

    Thanks for the input so far. I have not had any luck with the local yards. Any good source for wiring diagrams? I have found some pinouts and the Hanes manual shows some stuff, but the Hanes doesn't;t show what connector and pin the wire terminates in to the ECM. I'm going to pull the engine...
  4. R

    1999 7.4 Low sensor voltage P1122 P0122

    Anyone know the difference in the 1996-1997 computers and the 1998-1999 computers? I see one extra connector that has two wires in it. I have two of those for this engine/transmission combo, not to mention an extra wiring harness.... The only pace that I can find a flashed ECM is AutoZone...
  5. R

    1999 7.4 Low sensor voltage P1122 P0122

    I measured again this morning and I do not have a 5v reference voltage out of the ecm. I guess it’s time to buy and ECM. I did have it. Now I don’t. This may confirm that the ECM is really the problem.... More soon
  6. R

    1999 7.4 Low sensor voltage P1122 P0122

    Yep. It does make me think that the ECM is not the cause, but I’m out of other ideas. I also have two 1996 computers with this engine and transmission combo, I plugged one in and it would barely run. Didn’t investigate past that as I figured the pin outs are different because it has an extra...
  7. R

    1999 7.4 Low sensor voltage P1122 P0122

    Christian, I figured as much on the knock sensor. I believe that code is also a low sensor voltage. I guess my next test is to check voltage on those sensors while I am driving down the road. I have good voltage while sitting, just not after driving. Sometime its after a few miles...
  8. R

    1999 7.4 Low sensor voltage P1122 P0122

    My scanner does not show voltage. It does give me a linear graph showing what is going on. For the TPS, everything starts out ok and timing seems to be in the mid to high 20’s. After a few miles, the computer sees a 20% down to 0% and back and forth for the TPS. Like I’m letting off the gas and...
  9. R

    1999 7.4 Low sensor voltage P1122 P0122

    I did check voltage at the TPS and I am getting 5.1 volts. I have been looking at ECM's and they all say they have to be flashed or programmed for this vehicle to run properly.... Any experience with this? I don't mind paying someone to fix this, but I'm having a hard time with paying someone...
  10. R

    1999 7.4 Low sensor voltage P1122 P0122

    Christian, Thanks for the reply. I have removed and cleaned the grounds. I have one at the right rear head that goes to frame rail. Two that connect on to the right front of the block with the battery ground and two that connect to the thermostat housing. I have also replace the wiring in...
  11. R

    1999 7.4 Low sensor voltage P1122 P0122

    And yes, the ECM is for a 7.4.
  12. R

    1999 7.4 Low sensor voltage P1122 P0122

    That is correct. A 99 chassis, wiring and ECM. A 96 engine. The only difference I was able to see in the 96 vs 99 engine is that the 96 had a temp sensor in the right and left head where the 99 only had one in the left head....
  13. R

    1999 7.4 Low sensor voltage P1122 P0122

    Hello, I have been battling a bad running condition for about 8 months. I getting a P1122, P0122 and P0327. The first two indicate a low sensor voltage issue. I have replaced the wires in the harness and replaced my new TPS with a used one and as of today another new one. I do not believe...
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