The engine would stall, sputter, not start and had an engine light. The Van became unusable. I had a few engine faults that would vary on occasion. P0300, P0107, then later P0129, P0301. These basically pointed to the MAP sensor (Manifold Pressure). I replaced the MAP sensor (24.99) and it did not fix it. So I started troubleshooting it. There are 3 wires on the MAP Sensor. The colors vary, but one is a 5 VDC regulated signal that does not vary (comes from the PCM I believe). There is a ground, which if you have the 5 VDC, I presume the internal ground of the PCM is good. The last one is the one I had a problem with. With the key switched on (engine not running) you should get a signal that is approx. 4.5 volts. When the engine is running, the variable resistor should change with the Manifold Vacuum pressure. It should drop down to about 1 volt when you the engine is under load. If you had the MAP sensor removed and had a vacuum pump attached to it, you should see it change accordingly with the increase of vacuum pressure up to about 20 lbs. The harness coming off the MAP sensor is short, it is maybe 2 foot long to the first connection. It runs into a larger harness that I had to open up. These harnesses make an almost 180 degree bend and in this bend something strange is going on. The rubber insulator around about half of the wires is basically just melted. I think that the wrong type of insulated wire was used or something came in contact with them to cause this. I have no idea what caused it. I had to disconnect the fist connector and wrap about 6 wires that were touching each other. This would explain my intermittent problems I have had over the last few years. It is working great now. I am surprised this is not a recall item.
The engine would stall, sputter, not start and had an engine light. The Van became unusable. I had a few engine faults that would vary on occasion. P0300, P0107, then later P0129, P0301. These basically pointed to the MAP sensor (Manifold Pressure). I replaced the MAP sensor (24.99) and it did not fix it. So I started troubleshooting it. There are 3 wires on the MAP Sensor. The colors vary, but one is a 5 VDC regulated signal that does not vary (comes from the PCM I believe). There is a ground, which if you have the 5 VDC, I presume the internal ground of the PCM is good. The last one is the one I had a problem with. With the key switched on (engine not running) you should get a signal that is approx. 4.5 volts. When the engine is running, the variable resistor should change with the Manifold Vacuum pressure. It should drop down to about 1 volt when you the engine is under load. If you had the MAP sensor removed and had a vacuum pump attached to it, you should see it change accordingly with the increase of vacuum pressure up to about 20 lbs. The harness coming off the MAP sensor is short, it is maybe 2 foot long to the first connection. It runs into a larger harness that I had to open up. These harnesses make an almost 180 degree bend and in this bend something strange is going on. The rubber insulator around about half of the wires is basically just melted. I think that the wrong type of insulated wire was used or something came in contact with them to cause this. I have no idea what caused it. I had to disconnect the fist connector and wrap about 6 wires that were touching each other. This would explain my intermittent problems I have had over the last few years. It is working great now. I am surprised this is not a recall item.
- Lenard M., Jesup, GA, US