Could be a shorted sensor , have you replaced it ? Shorted wiring , A problem with in the instrument cluster . Would need to do some testing to find out what causes this . I would tell you to check power an ground of both circuits involved ,could you do that ? You would need pin out charts of the connectors that go to the instrument cluster . find the wire for coolant sensor , then find that same wire color at the coolant sensor an with ohm meter check to see if wires are shorted to ground etc...
The engine coolant temperature is operated by two coils. The battery voltage is applied to both of the coils. One of the coils is grounded directly and the other coil is grounded through the engine coolant temperature sender. The engine coolant temperature sender has a resistance of 44 ohms at 125?° C (260?° F). The resistance increases at lower temperatures. The resistance is approximately 1365 ohms at 37?° C (100?° F), causing the current through the engine coolant temperature sender at one of the coils to increase, as the coolant temperature decreases and moves the pointer.
The magnetic fields of the two coils moves the fuel gauge pointer. The two coils are at right angles to each other. The battery voltage is applied to the E coil and the circuit divides at the opposite end of the E coil. One voltage path continues to ground through the F coil, as the other goes to ground through the variable resistor of the fuel level sender.
The resistance of the fuel level sender is low when the fuel tank is low. A large flow of current passes through the E coil and the fuel level sender resistor. The current pulls the pointer towards the E on the scale.
The fuel level resistance is high when the fuel tank is full. The increased current flowing though the F coil moves the pointer to the F on the scale. With the two coils operating the pointer, the fuel gauge is not affected by the any changes in the voltage of the system.
Without being able to test the electrical circuits , I would say there is a problem inside the instrument cluster. You could take it out an have it tested or you could get a used one from a auto salvage yard for $15.00 an see if the problem goes away .
There is a pretty standard procedure for resetting the security in GM vehicles. This is it.
Perform the re-learning procedure
Turn ON the ignition, with the engine OFF.
Attempt to start the engine, then release the key to ON (vehicle will not start).
Observe the SECURITY light, after approximately 10 minutes the light will turn OFF.
Turn OFF the ignition, and wait 10 seconds.
Repeat steps 1 through 4 two more times for a total of 3 cycles/30 minutes ( the vehicle
is now ready to relearn the Sensor Data Code and/or passwords on the next ignition switch transition from OFF to CRANK).
Start the engine (the vehicle has now learned the Sensor Data Code and/or password).
Your specific vehicle does not actually claim that this works. This is for a few years after your vehicle, but it is worth a try. If it doesn't work, then you may actually have a failure on your hands that needs to be addressed. More info on this site. http://www.diy-gm-security.com/
I just answered a P705 question that may be connected to this.
But I will add that usually transmission codes will not turn on a check engine light. The reason is the check engine light is to warn the driver that something has happened that could damage the cat converter or cause major problems with emissions.
Check the fuse link in the small diameter wire coming off the battery cable. It is more flexible than a standard copper wire of the same size. If it's bad you can splice in a new wire in it's place. Just be sure it's the same gauge as the original.
you can visually see the lines. the 3/8" diameter line is the pressure line and the 5/16" line is the return line. you buy fuel lines for it and replace the O rings while you do them. if they are rusty then replace both lines.
You have to remove anything that is connected and in the way of the intake. Remove the fuel rail, the EGR valve and supply pipe from the manifold, the map sensor, the vacuum for the fuel pressure regulator, the alternator and support bracket, the water pipes for the throttle body, and the bolts that hold it down.
Well Jason you could have a bad fuel pump relay in the underhood electrical center . The PCM - powertrain control module turns on the relay . An your vehicle has a anti-theft system probably ! Is there A security light lit on the dash ? If not pull the fuel pump relay out of the electrical center an check for power an grounds , there will be two grounds an one battery voltage an one open . The open will be power when cranking the engine , this is the control side from the PCM . If you look on the side of the relay there should be a circuit diagram , an on the bottom the pin's should be marked 30 , 87 this is the fuel pump side of the relay. 87 is battery voltage , 87 goes to the fuel pump . Pin's 85 , 86 . 86 is ground an 85 is power from the PCM when cranking ! GM Fuel Pump Relay Testing
make sure that when it happens again check to see if there are any lite up lights on the dash that were'nt there before indicating that there may be a problem, if so find out what the sysbol means or you can take it into a shop and have them diagnose the problem