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a while back my truck went bezerck. surging, little or no throtle response, cruise control coutting on and off, temp gauge swinging wildly from 0 to max and the engine was surging while indeling and me standing beside the truck. i was already having some dead pedal issues and had puechased a new vp44 from blue chip diesel. thinking that might be causing the problem i installed the injector pump with no change. I had multiple high and low voltage codes on the iat, tps, temp and map sensors. also had codes on the cruise control, tach, system voltage. did some test on the tps and replaced no change, replaced the temp sensor no change, clock spring nochange, speedo(on board diagnostic said it was bad) no change. I cleaned and reconnected every ground i could find and checked the wiring to the sensors to the best of my ability and could not find any thing wrong. figured it must be the ecm and replaced. The surging and cruis control malfunction seem to have stopped. I still very little throttle response and the temp gauge pegs right after starting a cold engine. i connected a scan tool and erased the codes and the following is what i have left; 112, 1286, 1475, 563, 122, 343, 117, and 237. the scan toll showed the engine temp and air temp to be 293 degrees i guess thats why there is so little throtle response due to the enging thinking it is hot. i have checke the voltage to my tps, iat, map, and tps and all are around 5 voltsand appear to be functioning properly/ i recalibrated the tps with the pedal only did not know might have to adjust the voltage per the sticker on the back. i will do that when i get home. i checked resistance on the temp and iat sensors and they both seem to be fine. i did get a 606 code that i never had until replacing the ecm, but replacing it did cure a couple of my ills. i am not an electronics guy by any means but i am learning as i go. Has anyone encountere anything like this.

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i checked the voltage at the batteries still connected and the switch was off and had approx 12 volts. I checked at the batteries again with the engine running and had just over 14 volts. I have not checked the output on the alternator though.

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if youve got a bad diode track in the alternator it will still charge and might show a normal voltage reading but the alt. could be creating some really wild a.c. current that will feed through the whole truck and cause all kind of wierd problems, this cannot be checked with a simple multi-meter and the geniuses at the parts store might not catch it either, disconnect alt. wiring clear codes and run truck off batteries see if it starts acting normal and then replace alt.--- or i could be way off but easy to check and wouldent be the first time for me.

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bring this back up again. went home last weekend and cleaned up some other grounds i learned about here. still no change in codes or how the truck is running. i actually bought my rebuilt ecm from Auto ecu and not ace as i stated earlier. must have been asleep too. i have sent the ecm back to them and they agree there is still something wrong with it and say they are going to fix it. we'll see. while searching the forums i have seen a few references to the connection in the power distibution center not being tight. mine will tighten up to a point where the bolt does start to slip, like the threads are not long enough. should this connection be tight or is this purposely desighned this way to prevent over tightning? i have also read there is a bundle of wires under the driver side battery. i guess i will check those out next weekend and hopefully install a working ecm.

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Can you put a washer or two, maybe a lock washer, on the power dist pole to keep the threads tight?But typically bad power sources or loose grounds cause low voltage issues, not high voltage, so I still think you may have a charging or regulating issue. But rule out the easy stuff first, like loose wires.

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i am getting high and low voltage warnigs. i am getting sytem high voltage warning along with sensor low voltage warnigs. my altenator is putting a steady 13.7 to 13.8 volts and my sensors all are receiving 5 volts as they should. i probably can out washes under the connection, i was tying to figure out if it is pruposely this way to prevent over tightening of the connection. i will have to see if i can get the connector off as it seems there must be some form of clip on the end of the bolt because it did not seem to back out all the way when i last worked on it. hopefully my "working ecm" will be in my hands soon.

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i still suggest running vehicle with alt. output wire disconnected the batteries will keep the vehicle alive for a good 1/2 hour no problems

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