2016 Jeep Renegade not starting, replaced cam/crank sensors, no codes

Hi all. I wanted to provide as much info as possible, so this ended up being a long post. I’m feeling really stuck and can’t “take it into the shop” in the traditional sense, so I deeply appreciate you if you make it to the end.

We have a 2016 Jeep Renegade Limited with just under 25k miles. I’m in Alaska and don’t live on the road system - it came on a cargo plane. We do have an auto shop here that sometimes has a mechanic, but there is not one there now and it could be months or more until we have one again. That being said, I do know a few people that are much handier than I am and could help with many things…my own knowledge on the other hand is pretty limited. We bought the car in July and it’s been great until now. We bought it at a dealership but actually had a chance to get in touch with the previous owner, and she said there were no issues she was aware of, she just wanted something different.

So onto the problem… a few weeks ago the engine wouldn’t turn over. Luckily I have an ODBII scanner and plugged it in. It gave me the P0340 and P0335 codes for the camshaft sensor and crankshaft sensor. I ordered them both, waited, and discovered that the camshaft sensor was the wrong one and didn’t fit. I replaced the crankshaft sensor and it started right away! It felt pretty good to be able to fix it.

Fast forward about 4 days, and it wouldn’t start again. I plugged in the ODBII scanner, and no codes at all this time. I unplugged the battery for about 20-30 minutes to reset the computer, and still had the same issue - no turning over and no codes. I decided to order the correct camshaft sensor. It arrived today, I replaced the old one, and it didn’t change anything. No turning over and a check engine light with no codes.

Another thing to mention is that before I replaced either sensor, the check engine light would turn on, blink for a little, and then go back to solid. After I got it going the first time (with replacing just the crankshaft sensor), there was no check engine light at all until it stopped turning over again. At this point it is doing the same thing as before: solid, blinks a little, solid. This is obviously with just having the car on, not fully started. I know a blinking light can mean a misfire, but I’m not sure how to determine that or what is causing it, especially since it was fine for a few days.

A few other things that may be worth mentioning…It’s already below freezing here, but I do have a block heater. I also have a trickle charger that has been able to charge up the battery no problem. A few weeks before the issue started, there was some gurgling from the muffler. My friend said it was likely the water byproduct in the catalytic converter and that it hadn’t gotten hot enough for it all to evaporate. Drives tend to be shorter here - maybe as short as 5 minutes total, plus warmup time. It’s a small village but big enough for tons of folks to have a car here. So I suppose there could be more water than normal collecting in there. This is probably a stretch, but I wonder if the water froze and is blocking the exhaust from actually leaving.

I appreciate any thoughts or ideas! Thanks so much for reading all of this!

To clear up a little confusion here, turning over means the same as cranking. if the engine is not turning over, there is no rrr,rrr sound from the starter.

I think you mean the engine is not starting.

Try spraying some starting fluid in the air intake, if the engine starts and runs briefly you have a fuel problem. If not, you have an ignition or timing problem.

If your engine is not starting for any reason, the check engine blinking probably means nothing whatsoever. The check engine system goes through a self-test. Don’t use that to try to diagnose the problem. If the car is running, then the check engine light will light and you can read a code.

Ah, yep you are correct! I definitely had this misconception. It IS turning over, but it is not starting. I will try to get some starting fluid and report back.

Okay, this is helpful and makes sense with what I am experiencing. Thanks!

Ran ok and then no start. Any chance a critter chewed on wires?

Measure the battery voltage while cranking the engine, weak battery voltage/slow cranking can set P0335 and P0340 fault codes.

The flashing check engine light with the ignition on indicates that the OBDII monitors have not been completed, this is normal after erasing fault codes or disconnecting the battery.

If the drip hole in the muffler is blocked, water can accumulate, freeze and prevent the engine from starting. You may want to inspect the drip hole and heat the muffler to thaw the ice.

Ran ok and then no start. Any chance a critter chewed on wires?

Boy I hope not! But I’ll try to check later today.

Okay I’ll give that a try. I feel like the fact that the battery can be charged by the trickle charger without any error messages should be enough for it to start at least once, even if it is ready for replacement. Is that maybe not true?

Yeah I have space heater I could put under it for a while.

What is the temp?
Is fuel moisture free? Where does the fuel come from? Are you inland? Coastal? Barges?I suppose you could ask the local mechanics if cars/ trucks have issues with drive issues based on seasons.
It’s November. I assume it is not -30f. Did your last car perform ok?

Its hovering around freezing but has been as low as 10 since it started and has been in the upper 30s recently. We are coastal and fuel comes on a barge. I have heard of some moisture issues before but never had a problem so it could also be hearsay. Our last car was a 2001 Dakota that had a ton of problems and we decided to sell it to someone who knew what they were doing. I have some Heet I could put in the gas tank but I’m not sure how much good it would do without being able to get all mixed up.

2016 is a new car. A mechanic with a scan tool should be able to see why it’s not firing. Has spark. Has fuel. Motor is sound. If you literally are in a place with no techs then you are in a bind.

So by some kind of magic it started again last night!

I realized I had never disconnected the battery after installing the second sensor. And actually I didn’t do that after initially installing the first (crankshaft) sensor - it started up right away after that.

So anyway, Monday night I disconnected the battery and forgot about it until Tuesday afternoon. I reconnected it, connected the trickle charger for a few hours because why not, tried it again and BOOM! It might have been on the second try that it started, and it took a little convincing when it did start, but it started. The RPMs also dropped after it started and I thought it was going to stop running. This could also be a normal thing that I hadn’t noticed before since last night I was really trying to pay attention to all that was happening.

So the besides disconnecting the battery, the only other change was that the temperature was near 40 yesterday, warmer than it had been. I’m glad it’s working again but I sure wish I understood what happened. Thanks for all the input in here and I’d love to hear any thoughts from y’all about what the problem might have been.

Thank you for letting us know of your outcome.
I would suggest driving it for a minimum of 20 minutes each time you use it to get all the fluids warmed up. Though you drive very few miles, change your oil a minimum of twice a year. In Alaska I would use 0-20 synthetic oil. Keep a battery maintainer on it when not in use.
If your block heater is factory, check owners Manuel, see if it is sake to keep plugged in all the time when not in use. I would be concern about an after market block heater.

My kid had a Dakota and a renegade. He lives in Colorado and could not go above 12k’ elevation. Jeep would just die. Had altitude sickness. So he sold it. He gets a different rig every year. Sometimes more often. He is easily bored.