Hello, If you have the 5.9 gas engine.

Ok a vehicle needs three things to run- Air- Spark- and Fuel. We have to find out which one it is that is causing the problem. I know you might have already done some of these but I want to make sure we cover all the bases.

You could be a few things different things.
Here is what you could do to figure out what it is.

* Bad Battery or Bad Connection with the cables or terminals ends.
You need to test the battery for 12 volts, then do a load test to make sure the battery is strong enough under a load. If you can not do this test you can take the battery to Autozone and they will test the battery for voltage, and a load test for FREE. If battery is good, make sure the terminal and cables are good. Check the Ground cable on both ends for good ground and tight.
Note new battery can be bad, or to weak with cranking amps for the cold.

Check for a No Spark issue- Pull spark plug and reconnect it and lay it down so while you are cranking it you see is it has spark or not. If no spark could be a sensor, coil, Relay or the PCM.

* Check the Junction Box and Relays next to the Battery- Check all fuses in box and push down on all relays. If the vehicle is not starting, you can switch the Fuel, Ignition, Auto Shut Down( If it has a ASD, not all vehicles have it) and switch the Starter relay with a matching relay like the horn to see if it is a Relay problem(Do one at a time switching around)

* Check for codes- Keep checking for codes they can appear at any time.If you do not have a code reader please let me know and I can give you the test procedure to get the codes. If you do not have a code reader and do not have the type of vehicle to receive the codes, you can go to Autozone and rent the scan code reader for FREE . You just give a deposit and they lend you the tool to use, you read the codes, then write them down, then clear the codes. Then when you return the scan tool you get every dollar back from your deposit. Note- The computer will store old codes and will give false codes. The best thing is to clear all codes and then after you get the vehicle running, check in 100 mile to see if there is any new codes, if so then that part is bad and needs to be replaced. Checking for codes could help narrow down the problem. Like a Crank sensor, Cam Sensor, Mass Air Flow Sensor, Throttle Body,Vehicle Speed Sensor and so on. If it is a sensor you can find this out by just reading the codes in the computer. Note to confirm for sure the sensor is bad the proper way to test the sensor is by hooking a Diagnostic Scan Tool. In most cases if the code does say it is ..... Sensor always check the connection and for power before replacing it if you do not have the scan tool.

How to Check for Codes
You can get the codes out by cycling the key on and off three times.On the third time leave the key on and look at the check engine light or the odometer.If you have any trouble codes they will appear there.If you have any codes please let me know what you have and we can go from there. If the check engine light blinks it will blink slow for the first number like blinks twice then it will blink fast like five times, this means the code is 25.

Check the Timing Chain if loose or weak.





Check for Fuel Problem- Pour some gas down the throttle body, if the vehicle starts and runs for a little bit you have a fuel problem.It could be the fuel pump or its to weak, Fuel Relay, Restriction in filter,Wiring, or Module. You need to check for humming to the fuel pump when the key is in the on position. If no sound the fuel pump is not working, first check the relay, then check for power going to fuel pump, if no power to fuel pump you need to check the module. If you have power at the fuel pump and the fuel pump is not working then the fuel pump is bad.
Fuel Pressure test at fuel rail


Check Fuel Filter- could be partly plugged up

* Loose connection in the wire harness, or at the PCM Power Control Module.

* The other possibility is the Alarm System- Need to do a Relearn Procedure if your vehicle has accept one, or needs to be reprogrammed by the dealer

* Bad Ignition Switch, or Cylinder Lock

* Then if all the above is good then it is the PCM needs to be Reprogrammed or Flashed. The dealer calls it Flashing, what this is,is the PCM needs to be UPDATED with the new version software. The dealer has the software or a reliable shop that has the diagnostic new updated software scanner tool. The dealer hooks the scanner up and goes in to cleans out the old module and installs the new updates to have it work better. The PCM controls everything electrical in the vehicle. This cost is about $50.00 to $90.00. It only takes a half an hour to do but most of the time the dealer will charge you and hour in there labor.



Your vehicle could have only one problem to several problem it could to be a PCM problem.

If the vehicle does not accept the updates, the PCM will need to be replaced.

You can try yourself to Reset the PCM yourself ,by disconnection both Battery Cables and hold the battery ends together away from the battery. Hold the battery ends together for one min then re hook the battery cables back up to the battery and then see if that fixed the problem. I know it sounds silly but this procedure does help reset the modules.

I know I gave you a lot of possibility's but please keep in mind I am not there at the vehicle to hear, touch, test, or drive it. I am relying on the information you are telling me. I gave a lot of possibility's so in case it was not the first thing I said or the third thing you have all the steps of what it could be. Please do the this I suggested in the order so you go from the smallest repair to the worst last.

I

Please let me know if you need more help.

Thank you very much