2002 Caravan Won't Start Below 1/4 Tank

3.3L Flex-fuel. A friend called up and said it will crank, but won't start when the tank is less than 1/4 full.

I hooked up my scanner and went into the body module for fuel level info. At just a little over 1/4 full I read approximately 7 gallons.

I drove it 25 miles to my home and pulled codes P0601, P0124 and P1684. I parked in my driveway which has a steep incline and I siphoned off as much gas as I could getting at least two gallons out.

Refering back to my scanner it reads approx 5 gallons and just under the 1/4 mark. I've positioned the van backwards and forwards in my driveway and also on level ground always getting the same number of gallons.

Never once in several tries has the vehicle failed to start for me, but before quitting for the night I did notice a loud rumbling noise coming from the gas tank which I take to be the fuel pump. That makes sense since it's not submerged in fuel as the van sits facing up the incline and a weak fuel pump or impending failure is what I initially suspected.

The only "but" here is why won't it start when the fuel is below 1/4 tank? From what the owner told me the last time it did this the vehicle had been sitting all night.

Your thoughts or suggestions?

Could it be a coincidense? How many times has this happened?

The key may be the 601 code. The PCM is likely toast. When the brain goes strange things can happen. It may be covered under an extended emissions warranty. I believe it's up to 80K miles.

http://www.obd-codes.com/p0601

[QUOTE=RIP]Could it be a coincidense? How many times has this happened?

As far as I know this has occurred twice and each time he put gas in and it started up. One other time he was traveling and it started stumbling so he pulled into a gas station and it ran normally once he put gas in the tank.

The key may be the 601 code. The PCM is likely toast. When the brain goes strange things can happen. It may be covered under an extended emissions warranty. I believe it's up to 80K miles.

I'm going to suggest he purchase a new computer. I reset the MIL, but it came back immediately. The vehicle has only 73K miles on it, but we are stationed in Naples, Italy, so warranty work...let's just say is not the easiest thing to do overseas.

I stopped at a friends garage and he said he's seen this scenario four or five times lately. He has found a rubber hose in the fuel module deteriorated so in effect, the gas is coming in where the hose is ruptured/failed which is at a higher point than the intake screen. That makes sense and I wish I could check fuel pressure, unfortunately I don't have the correct fuel line adapter for my gauge.

Gee, looks like I'll have to buy a new tool:lol:

I think I'm going to tell him to buy a new fuel module as well since I didn't like the sound the pump was making when the gas level was low.

Thanks for the response.

Far from saying this scenario can't happen but, I've been roaming auto forums, mainly Chrysler or Toyota related, for 4-5 years now and I don't recall this one before. That plus your mechanic friend's multiple experience with this makes me wonder if the gas formula over there could be effecting the pump. Unfortunately, it sounds like the only way to verify it is to pull the pump.

Not sure the warranty applies outside continental USA. Might try calling Chrysler Corp. directly. If you're in the military ("stationed") might try checking with the First Sergeant or Family Services (or equivilent). They might have experience with making warranties work over there.

I wondered the same thing regarding fuel composition overseas and possible effects on flex-fuel lines. I've been overseas since Jun/2000, so my exposure to flex-fuel vehicles is practically non-existent.

I told the owner if he wanted me to do the job, it would be a new fuel module or nothing. He agreed to that as well as a new computer.

The vehicle was purchased through the Navy Exchange New Car Sales, so the owner said he simply submits a receipt to them and will be reimbursed. I didn't know that, but I'm glad to hear since our last car was bought through them.

Just waiting on the mail to deliver the parts and I'll post back when I figure (hopefully) out what was wrong.

Before spending a lot of money and time, drop a couple of bottles of HEET, Water Out, Dry Gas in the tank and see if that helps, every time I have had the problem you have it has been condensation in the tank, and below 1/4 tank she will react as you describe.

Before spending a lot of money and time, drop a couple of bottles of HEET, Water Out, Dry Gas in the tank and see if that helps, every time I have had the problem you have it has been condensation in the tank, and below 1/4 tank she will react as you describe.

Hey, that's not a bad idea.

Before spending a lot of money and time, drop a couple of bottles of HEET, Water Out, Dry Gas in the tank and see if that helps, every time I have had the problem you have it has been condensation in the tank, and below 1/4 tank she will react as you describe.


The owner informed me that he tried that and continued to have the same problem. That's when he contacted me.

I wondered about water in the tank, but discounted it because it seemed to me the pickup tube would be submerged in water no matter what the fuel level was. I'm glad you passed this bit of info to me; real life experience is much better than theory:thumbsup:

Living overseas with an American-made vehicle presents situations in which peace of mind trumps time/money. Since the vehicle is primarily used for family trips throughout Europe and will be driven to the owner's new duty station in Spain next year, we went with the worst case scenario and decided to replace the fuel module.

She's up and running fine after replacing the PCM (http://www.allcomputerresources.com/) and the fuel control module.

I was definitely below the 1/4 tank level during my test drive. According to my MT-2500 there was .87gl left in the tank when I pulled into the garage, so I'd say that's definitive proof the original problem is fixed:lol:

Only lessons learned to pass on would be if I had been in the states I would have ordered the PCM first and see if that fixed the problem. I'm waiting for the fuel module to dry out before I take a peek inside, but when I pulled it out the reservoir was almost full, so the "broken hose" theory didn't seem to hold water...or in this case, gas.:uhoh:

Thanks for everyone's help.

Glad to hear all is well. Thanks for posting the fix.