No crank, no start, code P0335

Hi,

I need to start from the beginning. The ignition C fuse can be causing issues as well as ignition fuse A. Both fuses are in the underhood junction box. I need these checked first. In addition to checking the fuses, make sure there is power to and from them. Here is a link you may find helpful:

https://www.2carpros.com/articles/how-to-check-a-car-fuse

Also, see if it will start if you place the transmission in neutral.

Next, I attached the entire starting system wiring schematic below. I had to cut the pic in half to make it readable, but I did overlap them. You can use this as a reference.

Also, switch the starter relay with a different one in the box that has the same part number. Or, here is a link that explains how to check one:

https://www.2carpros.com/articles/how-to-check-an-electrical-relay-and-wiring-control-circuit

If the fuses are good and the relay is good, we need to check the purple wire on the starter motor for power. It should only have 12v when the key is in the start position. You will need a helper when testing. Here is a link that explains the procedure:

https://www.2carpros.com/articles/starter-not-working-repair

Pic 3 below shows the fuse box underhood. I highlighted two fuses I need to have checked.

Let me know what results are found.

Take care,

Joe

See pics below.

Thanks for the info. was able to take a peak and get ign A pulled out this morning and it as a break in the fuse. I did not have my needle nose handy to pull out ign c but looking it seemed to be good. I intend to pick up a replacement today and will try to get it all back together to test it out. Anything I should look for as the cause for the fuse blowing out? Thanks for the help.

Hi,

If it has only happened one time, I wouldn't be overly concerned. Fuses get old. The truck is 20, and I bet that is the original fuse.

When you replace it, only use the same amperage fuse that you removed. That way if there is a problem, it will blow again and not cause other problems.

If possible, let me know if that takes care of the problem.

Take care,

Joe

I replace the Ign A 40 Amp fuse and now I have it cranking again! The truck will crank and then sputter a bit but every few minutes but it does not start. The fuel pressure gauge climbed to 50-55 once i started turning it over but still nothing.

I ran for codes again and the two engine codes that came up were P0335 and P0336 calling out the crankshaft position sensor. I just put a new sensor on a week ago.

Also, I know the gas is too old as well but it should still fire right? Seems like I can't win with this thing! Thanks again for the help.

Edit: just saw a post you (Joe) made about the CKP System Variation Learn Procedure on someone else's post so I will look into that. The problem is that it won't start at all so let me know if that is the right direction.

Hi,

Half the problem could be the old fuel. How old is it? Also, did you use an OEM crank sensor? I have seen so many bad aftermarket ones.

Before we do anything, I want you to try something. See if it starts for a couple seconds (normally) using starting fluid. If the fuel is bad, the starting fluid should make a difference. If it doesn't, move on.

Next, does your scan tool have live data? If it does, before removing the crank sensor, check for an RPM signal when cranking. Is it steady? If you find an erratic signal or no RPM signal, move to the next step.

Remove the crank sensor and inspect it. Does it appear that anything was hitting it? If not, return it to the parts store and tell them it's bad. I'm not saying it is bad for certain, but there is a good chance.

Since you have two codes specific to the CKP, I feel something is happening at that point, but can't be sure yet. The reluctor wheel that the CKP reads when the engine is turning can be damaged as well. Actually, if there is excessive end play in the crankshaft, it will cause damage. That's why I suggested removing and inspecting it.

One other thing. There are two grounding locations for the ignition coils. Both are on the left side of the engine, one in the front and one in the rear. See pic below. Check the condition of the grounds, wiring, and connector. It isn't uncommon for these trucks to have ground issues for the ignition coils.

The P0335 is related to the CKP, but testing is done at the powertrain control module. There could be a loose connection, corrosion, or water may have gotten into it and caused problems. So we really need to take this one step at a time.

Let me know the results from what I suggested. Also, the CKP relearn isn't causing it not to start. The vehicle needs to be running to complete the relearn.

If possible, record what it is doing and upload it for me to hear.

Take care and I'll watch for your reply.

Joe

See pic below.

I did try the starter fluid and there was no change. I will start working through the steps and hopefully we can get it going. The gas is 6 months old. but again the starter fluid did nothing.

Hi,

Six months should still run the engine. I was thinking years. LOL

Okay, start with checking for an RPM signal. If there is none, remove the CKP and inspect it for damage, check the connector for corrosion, or anything that seems out of the ordinary.

If there is a good RPM signal, then I need you to check the spark plugs for spark. Here is a link that shows how it's done:

https://www.2carpros.com/articles/how-to-test-an-ignition-system

If there is weak or no spark (a good spark will be blue in color and you will hear it). Weak sparks are usually orange or white. At that point, move the grounds discussed below.

If it appears to be good, check the grounds I mentioned. Interestingly, GM used connectors that would corrode and break. You may still have one good ground and one bad, or two partially bad grounds.

If the grounds are good, we will need to go to the PCM, but that is only if these other things all check good.

Take care and let me know the results.

Joe

I was able to run and check the RPM signal and there is none. I will continue looking into the CKP and go from there. When I replaced it, the old one looked good so I will start looking into wires for corrosion. I will attempt to test the voltage on the sensor as well to verify it is functioning properly. Thanks for the help so far.

Hi,

You are very welcome. Hang in there, we'll get it figured out one way or another. Let me know what you find or if there is something I can do to help.

Take care,

Joe

Here is an update with where I am at: I pulled the starter out of the way and took the sensor out and there was no damage or issue that I could visibly see with it. I went ahead and reconnected the battery to test the connector.

The middle pin on the connector is ground. I put the negative lead from my multimeter on that and the positive lead on the starter power cable and had 12 volts. I then connected the positive lead to the connector pin that is supposed to power the sensor and it read nothing. Looks like messing around with the connector that there is not a good connection of power from the PCM down to the CKP. The ground wire looks good though because of the good 12V read off the starter power connection.

If you have any advice for chasing down a bad wire I would welcome it. especially if you have a diagram of how those connections run through the wire harness so that I am not chasing it around to much.

Thanks again for the help.

Hoff

I did some more research and I did not have the key to the on position when measuring the voltage so I will retest later to verify my findings.

Hi,

Let me know what is found. As far as testing wiring, here is a link you may find helpful:

https://www.2carpros.com/articles/how-to-check-wiring

Let me know.

Joe

Solved! Was able to get a new sensor on there and it started right up! Idle was a little rough here and there but that is just because it sat for so long as I chased it down. Lesson here is that just because you get a fresh sensor does not mean it is a good one.

Thanks for the help!

Hi,

I'm glad to hear you got it fixed. I can't begin to tell you how many times I have dealt with a faulty new part. People on here deal with it as well.

In the shop, if a repair has anything to do with a sensor and I can get an original equipment part from the car's manufacturer, I do. I also do it for my own vehicle. Things like brakes, shocks, and other general things are usually fine.

Regardless, the rough idle is likely from sitting, the old fuel, and the computer relearning all the old values. Drive it and it should go away.

Take care of yourself and feel free to come back anytime in the future if you have questions. You are always welcome here.

Take care,

Joe