Failed smog

Reidsjeep · **Joined:** Tue Nov 13, 2018 10:40 am **Posts:** 18

My newly purchased 2006 Liberty crd has a check engine lite on and won't pass smog. My local garage/smog shop is telling me I need a new EGR air control valve (factory part 05142799 AA). He is unable to locate one so I was hoping for some adult supervision here.

This is my second Liberty crd. I bought one 10 months ago. Driving it the 250 miles home on the day I purchased it I discovered a very slow water leak( to slow to show up on test drives). After 2500 bucks pulling engine to get at it and investigate it I gave car to shop due to unrepairable cracked block.. Really a shame. Paid 9 grand and was beautiful car.

As you might suspect I am about ready to get a horse.

I did see somewhere on forum a reference to putting some kind of resistor on engine wiring to 'trick' check engine lite into remaining off. Perhaps some one could help me locate that info. And/or give me some advice on the wisdom of such an option.

Thanks

casm · **Joined:** Sun Jan 29, 2006 5:05 pm **Posts:** 694

Reidsjeep wrote:

My newly purchased 2006 Liberty crd has a check engine lite on and won't pass smog. My local garage/smog shop is telling me I need a new EGR air control valve (factory part 05142799 AA). He is unable to locate one so I was hoping for some adult supervision here.

This is my second Liberty crd. I bought one 10 months ago. Driving it the 250 miles home on the day I purchased it I discovered a very slow water leak( to slow to show up on test drives). After 2500 bucks pulling engine to get at it and investigate it I gave car to shop due to unrepairable cracked block.. Really a shame. Paid 9 grand and was beautiful car.

As you might suspect I am about ready to get a horse.

I did see somewhere on forum a reference to putting some kind of resistor on engine wiring to 'trick' check engine lite into remaining off. Perhaps some one could help me locate that info. And/or give me some advice on the wisdom of such an option.

Thanks

Couple of things:

Are you in California?
If so, what were the failure points on the smog check, and what were the numbers / comments?

You may have a bad EGR valve, or you may not. Before throwing parts at it, let's see what can (hopefully) be figured out.

It may be worth considering a tune for your vehicle, which could help with a number of driveability and running issues. See this thread for more info. This item might also be useful in conjunction with that.

Reidsjeep · **Joined:** Tue Nov 13, 2018 10:40 am **Posts:** 18

6 codes
P1140 egr throttle control
P0128 thermostat
P0100 maf
P0504 brake lite switch
P0589 s/c multifunction
U0121 lost communication with abs

I'm in california. My skills with a wrench are modest. Brake jobs, timing bets on uncomplicated cars, head gasket on my old 4 cylinder diesel, etc...
Electrical skills almost non existent. Change a lite bulb and....that's all I can think of.

I really really appreciate some suggestions.

casm · **Joined:** Sun Jan 29, 2006 5:05 pm **Posts:** 694

Reidsjeep wrote:

6 codes
P1140 egr throttle control
P0128 thermostat

Interesting. Is it running cold or hot? Also, have you tried replacing the temperature sensor at the thermostat housing?

Quote:

P0100 maf
P0504 brake lite switch

MAF is easy to replace. Have you checked brake light function? If the switch is toast, none of the lights should come on when you step on the pedal.

Quote:

P0589 s/c multifunction
U0121 lost communication with abs

Check grounds. This may also clear up other codes.

Quote:

I'm in california.

Thanks for the confirmation. I suspected that you were when you referred to an emissions inspection as a smog check; there's pretty much nowhere else in the country that uses that terminology for it.

Here's why I asked: as you're probably aware, this is a vehicle that was never sold new in California, and it has to pass both visual equipment and tailpipe inspections. It's also a unicorn as far as both CARB and the DMV are concerned, so certain things that might work in other states won't in your case.

(Ex-SoCal resident here; I'm pretty familiar with what is involved with CA smog tests.)

Quote:

My skills with a wrench are modest. Brake jobs, timing bets on uncomplicated cars, head gasket on my old 4 cylinder diesel, etc...
Electrical skills almost non existent. Change a lite bulb and....that's all I can think of.

I really really appreciate some suggestions.

Let's go through this step by step. Did you check out the links I gave you previously?

TKB4 · **Posted:** Sat Jun 06, 2020 10:26 pm

so like he said did it pass the tailpipe test ? If the tailpipe test was done and it passed that part the one way to cut light off would be to disconnect the bulb however you wouldn't get a CEL that might be helpful but you could still check the codes. The DIY tunes could cut off

On our DTC code list
P1140 is short circuit or open circuit in vacuum solenoid wiring (its located on right inner fender near the turbo with vacuum line )
p0128 is thermostat rationality meaning the signal basically doesn't make sense to the computer
P0100 Maf sensor voltage either too low or too high

P0504 Brake switch circuit plausibility with redundant contact
P0589 S/C switch number 2 either implausible voltage either too high or too low, stuck switch,
U0121 lost communication with ABS

Not sure but dont believe the last 3 related to brakes would cause a failed emissions test But maybe inspection.
The first three codes likely have absolutely nothing to do with the EGR valve. Most likely there is either one or more wires shorting to ground or more likely one or more bad grounds that need cleaning. I would suggest starting with cleaning all the grounds and dont forget there is also one near headlight in front of battery and below it. I would also closely examine the wiring that goes to the thermostat and part of that loom also goes to the mass air flow sensor on the air Box . Also disconnect these sensors and make sure clean and reconnect and recheck the codes. You might also perform the guage cluster tests follows:
1. Push and hold down the odometer reset button
2. Turn key to on position. Do not start.
3. Release the odometer reset button

This should initiate a self check of gauges causing all the warning lights to cycle on and off and gauges to operate such as temp guage going to I think about 9 o clock the 12 o'clock then higher etc. This proves the gauges can work .

I would be willing to bet that when you are driving it now the temp needles occasionally jumps around a lot (mine did with a short. You could also unplug the MAF sensor for now and leave unplugged and see if the code changes.

You may also have a short in ABS system or a bad sensor or still could be bad ground. Is the ABS light on ? I think you can turn the ABS system off with button on steering column but dont think it will resolve the codes . I assume #2 means a particular wheel such as right front but dont know which it should be in the service manual.

TKB4 · **Posted:** Sat Jun 06, 2020 10:30 pm

Posted at same time . Agree check ground clean and reattach. See rest of my steps also but though this may be difficult to find it is highly unlikely a failed part except possibly related to the brakes.

Billybob · **Posted:** Sun Jun 07, 2020 2:50 am

The 2006 KJ CRD has a known problem in that the Fuel Filter Mounting Bracket clamps down on a large wiring harness going behind it...forcing the harness against the Firewall! :shock:

This can cause wires to short to the Firewall (ground) or cause random wires to short together.

So unbolt this bracket and move it aside to inspect the harness for any damage.
Repair any damage and wrap some thin sponge around the harness to give it some protection against further damage!

This may not fix your immediate problems but will stop future problems showing up which may leave you stranded! :wink:

Billybob · **Posted:** Sun Jun 07, 2020 2:57 am

Double post!

TKB4 · **Posted:** Sun Jun 07, 2020 8:39 am

Yes definitely check the harness behind the filter head on a 2006 model . Also the 2005 models dont have the traction control system or the button on steering column ESP OFF button. 2006 model also doesn't have the separate FCM or front control module so one less thing to worry about

casm · **Joined:** Sun Jan 29, 2006 5:05 pm **Posts:** 694

TKB4 wrote:

so like he said did it pass the tailpipe test ? If the tailpipe test was done and it passed that part the one way to cut light off would be to disconnect the bulb however you wouldn't get a CEL that might be helpful but you could still check the codes.

One thing to keep in mind about California smog checks: a CEL is an instant fail. Doesn't matter what it's for; if it's on when you go for the test, you're done. This means that the tailpipe test won't (or shouldn't) take place.

As for pulling the bulb, part of the test is checking that the MIL illuminates then goes out (i.e., passes its own self-test) when the ignition is first switched on. If it doesn't do that, that's also an instant failure. Depending on how much of a jerk the tester is, you may also get a 'tampered or missing emissions equipment' notation attached to your test, which could lead to all sorts of fun things you don't want to have to do, like taking the vehicle to a referee station for its tests both present and future. Trust me on this one; I'm speaking from direct experience.

There is an exception to this, and that's if you go for a pre-smog. It's basically a full test including tailpipe, but the results (pass or fail) aren't counted for the purposes of registration - it's just a run through the test to give you an idea of where the vehicle might land if it were put through normally.

I'm leaning towards sensors and / or wiring on this one. Also, forgot to ask if there were any blown fuses, either under the hood or in the passenger compartment fusebox. That may help to narrow things down.

flash7210 · **Posted:** Sun Jun 07, 2020 10:30 am

P1140 is the Flow Control valve. It’s the throttle body type thing on the drivers side engine intake.
Check to see it’s unplugged.

The p0100 MAF code is likely related to the p1140 code. The two kinda work together.

Many here have removed their flow control valve. Maybe someone can sell you one they no longer need. Or check eBay

Or you can load a free DIY tune to eliminate the code. But can’t guarantee that the tune will make it pass the emissions test.

Also, I’m no expert on CA emissions testing, but I’m pretty sure the 06 Liberty needs to run on a 4-wheel roller. If it isn’t, the traction control system will cause problems.

TKB4 · **Posted:** Mon Jun 15, 2020 8:31 am

Casm

Just for my information. Would say an antilock ABS light on or a tire pressure sensor light on that is not part of the Check engine system cause the vehicle to fail inspection even if the brakes did not otherwise need work. What about only a tire pressure light on like when one sender unit is dead ?

TKB4 · **Posted:** Mon Jun 15, 2020 8:34 am

I might have a flow control valve if you need one from my salvage jeep.

casm · **Joined:** Sun Jan 29, 2006 5:05 pm **Posts:** 694

TKB4 wrote:

Casm

Just for my information. Would say an antilock ABS light on or a tire pressure sensor light on that is not part of the Check engine system cause the vehicle to fail inspection even if the brakes did not otherwise need work. What about only a tire pressure light on like when one sender unit is dead ?

None of those should cause a failure. However, there are a couple of things at play here:

On a California smog check, unless things have changed in the last couple of years, codes are not read from the OBD-II port. Some states do this (e.g., Washington), but California only checks to see if the MIL is on or off and working properly, and, if it's on, they don't care why it's on - you just get a failure.
If a manufacturer illuminates the MIL for ABS, TPMS, or other non-emissions-related reasons, that will cause a test failure since codes aren't read at test time. It's rare that a manufacturer does this, but there are a few vehicles out there that do.
If the person running the test is a real jerk (or incompetent, which is not uncommon), they may try to fail you for TPMS, ABS, airbag etc. lights being on. Legally, they can't, but it does happen. Appealing that is a nightmare.

And don't even get me started on the roadside spot checks - how those are legal is beyond me. So glad we no longer have to deal with any of this.

Failed smog

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