Bought a couple months ago. Several codes thrown, but currently no codes after installing new battery. Underlying issues still need to be resolved, though, especially since they're likely costing fuel economy. I'm getting 14-15mpg and would prefer.. better. The following are codes that have come up over the last couple months. Any input on the most logical things to inspect/clean/replace etc to improve fuel economy is appreciated!

Others report an average of 17.2mpg on fueleconomy.gov. I don't drive with a heavy foot and do have a scangaugeII hooked up to display live mpg etc (to consciously drive with fuel economy in mind) Mixed city/Hwy/rush hour ave 14-15mpg. Would prefer ~18+. I suspect one reason is a high idle wasting fuel unnecessarily.

Codes it's thrown:

0442 minor vac leak in fuel system. I'm told this is likely a hose on top of the gas tank with a pin ***** vapour leak. I bought a new oem gas cap to replace the original one just in case it's the gas cap seal.

0507 high idle intake air controller. What causes high idle? Specific hoses or sensors to inspect? Not sure what the idle rpm should be, but I see it fluctuate from just over 700rpm to well over 900rpm while fuel consumption at idle is 0.54gph to 1.00gph so sometimes it's burning TWICE as much gas at idle as it should. Usual idle consumption is around 0.65-0.73gph but obviously I'd prefer if it would stay down closer to 0.54 or lower! I highly suspect that the majority of excessive fuel consumption is being caused by the root cause of a high/fluctuating idle.

0401 low flow egr. Any affect on fuel economy? Specific things to inspect, clean, or replace?

0456 EVAP - not sure what this is all about, but it sounds related to everything else.

0461 fuel level sensor circuit - gas needle would suddenly drop to empty. It hasn't done this again since replacing the battery. May have just been due to weak battery?

2066 fuel level sensor B. Obviously related to above. Fuel gauge has been fine the last few days since replacing the battery.

0700 transmission control system - this code only showed up when the battery was dead and hasn't come back on. I assume it had to do with the battery being dead.

0562 lower than requested voltage. This one was also only on when the battery was dead and I assume because of it.

Other quirks:

Voltage fluctuates from 13.~4 to 14.2 volts. Is this a normal output range?

Horn randomly goes off day or night while the car is off or being driven. Sometimes for a split second, other times it blares for 10+ seconds and then shuts off. If it goes off while driving then the slightest jostle of the steering wheel turns the horn off w/o pressing the horn button at all. I'm almost completely certain from symptoms that it's the clock spring inside the steering wheel behind the airbag that's faulty so I've already ordered a new one.

We measured the draw on the battery when the car is off and it's 0.9x amps, which seems high to the guy who tested it. We started pulling fuses and relays to find out what was drawing power and expected it to change when we pulled the horn fuse and horn relay, but it didn't. The biggest draw was when we pulled the fuse for the "CLSTR, CHMSL (??), STOP LP, ABS" as it dropped from 0.9A to 0.3A. Instrument gauge cluster and ABS brakes I get, but what are the other things on this fuse? Is 0.9A draw normal? Is this fuse' circuit related to the clock spring at all and replacing it may reduce the draw?

Sometimes the climate control display part of the dash lights dim. When I notice I turn it off/on and within a couple minutes it brightens up. Odd.

Tire pressure is fine. Running 35psi as per recommended psi for the car.

Air filter is OK but have a new one on order.

Previous owner never changed the spark plugs and the original owner may not have either. Approx 140k km/86k miles. I've ordered new ones.

There are no obvious vacuum or major fluid leaks. There is some oil on the engine that could be from a hose leak or valve cover gasket leak, but nothing major. I'll likely get it into my friends shop and start taking things apart to inspect hoses etc for leaks underneath the intake manifold.

I like the car. It's nice. ~18mpg I can accept.. but 14-15? That's a lot of extra fuel considering how much I drive and the high price of gas where I live. Hopefully with a little help I can get things sorted out and running better and I can justify keeping it.

 

Have an 05 AWD Pacifica since new and have been getting 14.5 to 15.5 MPH for a decade on my commute maybe averaging 40 mph, not city driving. That gas mileage does not seem out of line to me as I do not have a lead foot.

 

I have to agree. I've had 3 pacifica's and they're all gas hogs. 15/16 mpg average is about normal for an older pacifica..My first 06 would get 25mpg on the highway with the wind at my back. 20 to 22 normal. It sounds to me like you may have an intermittent short somewhere in the instrument cluster. Unplug the climate control unit to see if that drops the overall draw..The horn could be something as simple as the switch in the steering wheel shorting out. I would assume that you have looked at the horn wiring? Try unplugging one of the 2 horns and see if it continues and then try the other..You never know...

 

I haven't fixed anything else yet but am getting better fuel economy. First 30 miles I averaged 21.3mpg. Then with the next couple trips that dropped to 18.7 over ~130miles. Currently 18.4 over ~180miles, which included a few hard accelerations due to avoiding some bad drivers.

The difference? It's Spring Break here for most public schools for two weeks and there are a LOT of cars off the road as parents tend to take time off work to be with their kids vs try to find alternate care for their kids at great expense. Smooth sailing to and from work means not much idling time - idling; I'm still pretty sure there's excessive fuel consumption at idle and that compounds the problem.

Anyways, this is pretty huge. A 3.5mpg increase represents a nearly 25% fuel savings, which is ~$120/month or so as 87 octane is currently $137.9cdn/L which is $5.22cdn/us gallon. So, besides maintenance and repairs that should increase fuel economy, it's pretty key to avoid idling time that gets exactly 0mpg and especially while the car is sucking back excess fuel at idle. If I drive a little earlier in the morning I can avoid a lot of gas sucking congestion etc.

Very sure the horn problem is in the clock spring based on symptoms. I haven't had the steering wheel off yet as I have to go borrow a steering wheel puller from a local shop ($80 deposit) and will just wait until the new clock spring arrives in the mail. I'll likely tear into inspecting some other things when I'm in my friend's shop, too. I'll unplug the climate control unit and test the draw then, too. (No multimeter at home.)

Codes 0442 & 0456 have returned. I have a new gas cap to install and see if that fixes anything.

I like the car and all. If I can get 18ish regularly and even better on weekend trips throughout the Summer, I can easily justify driving it. 15 combined and it's kinda hmmm maybe I should fix these quirks and sell it. It's nice to drive, though.. and the ride height/size definitely make me feel better than driving around in my previous 1990 Honda Civic hatchbacks.. sort of a "power position" thing (as per some TED talks) that leaves me feeling more confident and assertive all day, which will make me plenty more money in life over the long run, which will make he price of gas irrelevant.. :P aside from the environmental impact, that is. So if I did sell it I'd want something biggish or bigger, and something like that that's more fuel efficient is a lot newer and more expensive than the family deal price I paid for this.

 

Are you using 87 octane fuel? Just FYI Chrysler does recommend 89 octane, at least for the 3.5 and 4.0L engines. I don't know if it's recommended for the 3.8 but I would imagine it does...So I went to look at DTC 0442 in the factory repair manual.. No code 0442.... There is a P0440 which points to general EVAP system failure, and P0441 EVAP purge system performance, and P0443 purge control circuit.. P0456 is EVAP system small leak. Possible causes are EVAP purge solenoid vacuum supply, EVAP purge/tube obstruction and EVAP system leak.. So it's either a vacuum leak/blockage in the EVAP lines or the purge solenoid. Inspect the EVAP system hoses for cracked or dried lines, seal points, damaged or missing components and incorrect routing of hoses or tubes according to the manual.. I would suspect that any of these issues would lead to another EVAP system code being thrown, so hopefully this will give you a lead to finding your problem. Replace the gas cap asap if you have a new one.. Make sure that the PCV valve is working properly and replace air filt and plugs as soon as possible too. I'm willing to bet your MPG gets much better..Wouldn't hurt to run some good fuel system cleaner through it too or take it to a shop that offers a 3 part fuel system cleaning.. It's a little expensive but if your fuel system is badly gummed up it will greatly improve your performance and mpg.. I can tell you that with all 3 of the pacifica's I've had, they've all used mad gas when it's cold out. I live in central NY and in the winter it uses twice as much gas as it does in the summer.. My wife likes to warm it up before she drives it in the winter and it seems like the gas gauge goes down as fast as it goes up when I'm pumping gas in! Yesterday I drove it out in the country on a somewhat level road. I was averaging 40 to 50 MPH for about 40 miles and it got 19 MPG with maybe 3 or 4 stops.. Not too bad for being 32 degrees out.. It seems to guzzle the gas while it's warming up...

 

87, yes. Pretty sure I recall reading 87 in the manual. Will double check.

Replaced the gas cap today since I had a new one. Only lame thing is that the replacement doesn't have the hole in the back of the cap for the "strap" to plug into so you can't lose it. Ah well.

Ordered plugs and air filter thru my friend's shop. Will do the same for any other parts - way cheaper.

Any engine will use more fuel when cold and all get 0mpg while idling whether warming up or sitting in stopped traffic.

Maybe I'll run some kind of fuel system cleaner through.

Will wait for a time when I can use my friends shop to inspect various hoses etc. Clean, dry, covered, heated, bright etc.

Re: Repair Manual Is there any particular book/brand that's the best or best value? A quick google says oem shop manual is $100USD and download PDF versions are $15. Kinda prefer hard copy. Some othe publisher suffice for less money or ?? Thx!

 

The manual I have is the factory repair manual specific to the 08 pacifica. It covers everything in extreme detail. It's 4 books that are all almost 2" thick.. I got it on ebay for $60, but there are others. I had one for my 06 that I sold. It was only 1 book that was roughly 2" thick and was specific to the 06 and all options available in 06. I wish I still had it because I now have another 06..My wife disposed of the 08... You might be able to find a factory manual specific to the 04 on ebay... I used to use Chilton's etc but prefer the factory books.. I have the disc that they're selling on ebay that supposedly covers 04 to 08, but there was absolutely nothing on it that refers to the 4.0L engine and I didn't look but it probably doesn't cover the 6 speed trans either..I'm pretty sure it covered everything from 04..If you'd like to have it I'll give it to you for $5. You can send me a private message if you want it. I'll check it to make sure it covers your engine and trans....Dave

 

I might look for an oem repair manual hard copy.

Appreciate the offer of a disc, but no longer have any optical drives in the house and would have to trouble someone for use of theirs. An old school hard copy boook would be best for me.

 

Replaced the clock spring last night.. went to return the steering wheel puller and the horn blared again before I got around the block and now doesn't shut off when you jostle the wheel. I turned around and it went off again on my drive back around the block.

Back to square one. WTF makes the horn go off randomly whether the car is on or off???

And now it's hmmm do I pull the wheel and swap the original clock spring back in and sell the new one? Or sell the old one as a used part? New one cost $260dn all in, used one seems to go for about $80cdn. Hmmm, should I just leave it and know it's new ?? Hmm. What would you do? Better yet, what will solve this annoying problem?? Grrr.. not fun.

 

This is probably a dumb question, but did you look at the switch in the steering wheel to make sure it's not shorting out? Not even sure there is one but there may be a horn relay. Check that too. It's shorting out somewhere. Just have to find it.. Have you tried tracing the wires through the steering column? Are both horns going off when this happens? got to eliminate one thing at a time. At least you know it's not the clockspring? If they are that expensive, I'd pull the wheel again and take it back.. Then you can check the switches in the steering wheel. I would assume that the short is in the steering wheel if it used to go off when you turned the wheel, or could that have been coincidence? If you think it definitely was turning off when you turned the wheel, it's more than likely in the wheel or in the steering column. See if you can see any wires or a wiring harness move when you turn the wheel, or try moving them around by hand and see if you can get the horn to go off or stop going off..