Bad PCM, bad temp gauge, runs bad & ignition off draw
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Joined: Feb 2015
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Yes, with motor cold and not running the gauge pegs hot and stays there. I replaced the coolant temp sensor but not the gauge cluster.
I ordered a odb2 blutooth reader and will run with the Torque app to see what temp the computer is seeing. Should get it this week.
I ordered a odb2 blutooth reader and will run with the Torque app to see what temp the computer is seeing. Should get it this week.
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Joined: Feb 2015
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Figured I should give this thread an ending. I know I hate reading about issues that never have an ending.
Turns out the temp gauge pegging out was just a loose connection at the coolant temp sensor. After pulling half my wiring harness apart I got the Torque app and a blutooth obdII reader. When hooked up it showed that when the wires to the sensor were shorted out it pegged the sensor out and when it was unplugged the temp wouldn't move. The gauge in the truck pegs out whether the wires are shorted or unplugged. I am not sure why this is happening but with a good connection to the sensor the temp gauge works properly. Looking back my temp gauge started acting like this after I replaced too vacuum check valves. I must have moved the wires just enough to jiggle the connection to the temp sensor. It just really threw me off that it was pegging hot before the truck was even started. With a new set of plugs all the skipping went away (50 miles with the choke on really fouled them). Also the ignition off draw issue went away with getting the new PCM so there must have been an internal fault with the old one.
The truck runs good now but doesn't have as much power as I hoped it would. Even with a utility trailer with maybe 1,500lbs it won't maintain 65mph without down shifting on the slightest of uphill grades. I would hate to have close to the 7,250 max trailer weight, I think it would refuse to move.
Next up is new steering components and a new gasket for the oil pan.
Turns out the temp gauge pegging out was just a loose connection at the coolant temp sensor. After pulling half my wiring harness apart I got the Torque app and a blutooth obdII reader. When hooked up it showed that when the wires to the sensor were shorted out it pegged the sensor out and when it was unplugged the temp wouldn't move. The gauge in the truck pegs out whether the wires are shorted or unplugged. I am not sure why this is happening but with a good connection to the sensor the temp gauge works properly. Looking back my temp gauge started acting like this after I replaced too vacuum check valves. I must have moved the wires just enough to jiggle the connection to the temp sensor. It just really threw me off that it was pegging hot before the truck was even started. With a new set of plugs all the skipping went away (50 miles with the choke on really fouled them). Also the ignition off draw issue went away with getting the new PCM so there must have been an internal fault with the old one.
The truck runs good now but doesn't have as much power as I hoped it would. Even with a utility trailer with maybe 1,500lbs it won't maintain 65mph without down shifting on the slightest of uphill grades. I would hate to have close to the 7,250 max trailer weight, I think it would refuse to move.
Next up is new steering components and a new gasket for the oil pan.
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Joined: Apr 2010
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From: Clayton MI
Don't tow in overdrive, that will dramatically shorten the life of your trans.....
How many miles on the truck? Changing my timing chain and gears at around 170K miles made a BIG difference in perceived power.
How many miles on the truck? Changing my timing chain and gears at around 170K miles made a BIG difference in perceived power.