Check engine light - Random/Multiple Cylinder Misfire?

hgrimberg · **Joined:** Mon Dec 19, 2011 11:03 pm **Posts:** 363

A check engine light showed up. I scanned it and these were the results:

Fault log report generated by Torque for Android
=================================================

Vehicle VIN: 1J4GL48555W694731
Vehicle Manufacturer: Jeep
Vehicle Calibration ID: Not present

Current Fault Log
------------------
P0504: null

Pending Fault Log
------------------
ECU reports no pending faults

Historic Fault Log
------------------
ECU reports no historic faults
Other discovered fault codes
(possibly pending, current or manufacturer specific)
----------------------------------------------------
P0300: Random/Multiple Cylinder Misfire Detected
B2TAE: null

End of report.

Recently, I changed the fuel filter and air filter and after that I had some issues when cranking. Some times cranking was taking too long. Just 5 months ago, I replaced all 4 glow plugs because some of them were burnt.
The first P0504 code is one I get very often, probably hitting the brakes while hitting the other pedal.
When this check engine light started, I was trying to put it in Cruise control mode and it was not working, so I press the on/off button many times trying to make the cruise control work. Only after I restarted the engine, the cruise control started to work again.
Any ideas of what could be happening?
Should I clear these codes with my scanner and see if they show up again?

Hexus · **Posted:** Sun Dec 29, 2013 7:16 am

Yes, also change your fuel filter again. Even brand new ones can be defective, I suggest the NAPA gold because it's made by Wix.

Do you have the 1st or 2nd generation fuel head? If 1st, get the 2nd, if 2nd, get a new fuel filter and try it out.

hgrimberg · **Joined:** Mon Dec 19, 2011 11:03 pm **Posts:** 363

Most likely I have the 1st generation fuel filter head because it has never been replaced. The fuel filter I installed is a german Mann, probably better than the Mopar.
But, you said it was a good idea to clear the fault codes and see if they show up again, right?
Maybe it was just something that got fixed by itself...

Hexus · **Posted:** Sun Dec 29, 2013 10:52 am

Even a brand new filter can pick up a bunch of sediment. I have literally put in a brand new (Wix - NAPA Gold) filter once and found that I still had an issue.

I posted here, and read some other posts, about people with the filter being brand new being clogged. I replaced it, cut the new replacement open, and sure enough it was nearly packed and had only been in the jeep about 1200 miles.

You need to upgrade to the 2nd gen fuel head, it'll come with a new filter and solve both of your problems. You just have to splice 1 wire for the new connector and you'll install it the same as the old one.

hgrimberg · **Joined:** Mon Dec 19, 2011 11:03 pm **Posts:** 363

Well, I cleared the fault codes and they didnt showed up again. That was good. But today I left the car parked on a steep slope and then it had some issues cranking. It took a long time of cranking like if the diesel fuel was not getting to the engine...

EAB · **Joined:** Tue Sep 06, 2011 9:39 pm **Posts:** 141

I did a little search and both codes are covered in 2 different TSBs. They both involve flashing the PCM so in your case I would pass on these options since it looks like you have not had the F37 flash done (lucky duck).

P0300:
SUBJECT:
Flash: Improved Driveability And Erroneous DTC's
OVERVIEW:
This bulletin involves selectively erasing and reprogramming the Engine Control Module
(ECM) with new software.
MODELS:
2005 (KJ) Cherokee (International Markets)
NOTE: This bulletin applies to Cherokee vehicles equipped with a 2.8L diesel engine
(sales code ENR) built before February 13, 2005 (MDH 0213XX).
SYMPTOM/CONDITION:
The customer may experience one of more of the following driveability and/or erroneous
Diagnostic Trouble Codes (DTC's).
Driveability conditions:
• Hesitation during light throttle acceleration.
• Engine surge at low speed steady-state operation.
• Driveline vibration under light load.
• Glow plug/lamp duration too short on cold start.
Erroneous DTC's:
• P0087 - Fuel Rail Pressure Malfunction Pressure Too Low.
• P0093 - Fuel Rail Pressure Malfunction Maximum Positive Deviation.
• P0101 - MAF Sensor Signal Deviation Faults.
• P0234 - Boost Pressure Sensor Negative Deviation.
• P0299 - Boost Pressure Sensor Positive Deviation.
• P0300 - Misfire Detected.
• P0401 - EGR Solenoid Circuit Negative Deviation.
• P0402 - EGR Solenoid circuit Positive Deviation.
• P0513 - SKIM System Faults.
• P0560 - ECM Voltage Too High Or Too Low.
NUMBER: 18-007-05
GROUP: Vehicle Performance
DATE: February 03, 2005
• P0564 - Speed Control Switch #1 Signal Circuit Faults.
• P0585 - Speed Control Plausibility Between Sw #1 and #2.
• P0589 - Speed Control Switch #2 Signal Circuit Faults.
• P1001/P1002 - Engine Off Timer Faults.
• P2296 - Fuel Pressure Solenoid Short Circuit.

P0504:
SUBJECT:
FLASH: Engine Start and Driveability At Altitude Or Brake Switch DTC P0504
OVERVIEW:
This bulletin involves selectively erasing and reprogramming the Engine Control Module
(ECM) with new software.
MODELS:
2005 - 2006 (KJ) Liberty
** 2006 (KJ) Cherokee **
NOTE: This bulletin applies to vehicles equipped with a 2.8L engine (sales code
ENR) built prior to November 21, 2005 (MDH 1121XX).
SYMPTOM/CONDITION:
The vehicle operator may experience one or more of the following:
1. At an altitude of 5,000 ft. or higher, a cold engine start and/or warm engine restart that
is followed by a slow to idle up condition (domestic market vehicles only).
2. At an altitude of 5,000 ft. or higher, an Idle and/or off-idle engine shake during engine
warm-up condition (domestic market vehicles only).
3. A MIL Illumination due to DTC P0504 - Brake Switch Signal Circuits Plausibility With
Redundant Contact (domestic and international market vehicles).
NUMBER: 18-038-05 REV. A

hgrimberg · **Joined:** Mon Dec 19, 2011 11:03 pm **Posts:** 363

Humm, so it seems they are erronous trouble codes... They suggest me to update the software on my ecu but you also say I am lucky to have the old one.
Thank you!

hgrimberg · **Joined:** Mon Dec 19, 2011 11:03 pm **Posts:** 363

I still have cranking problema when parked on a slope facing uphill

Auberon · **Posted:** Wed Jan 01, 2014 8:05 pm

By cranking problems when facing uphill - could you please describe in more detail what you mean by the term "cranking problems".
Thanks.

hgrimberg · **Joined:** Mon Dec 19, 2011 11:03 pm **Posts:** 363

Auberon wrote:

By cranking problems when facing uphill - could you please describe in more detail what you mean by the term "cranking problems".
Thanks.

Well, it takes longer than usual to start the engine. Have to crank more than once.

Auberon · **Posted:** Sat Jan 04, 2014 3:44 am

Thanks. I presume you've checked everything for tightness to do with the filter installation, that is. It kind of sounds like you have a slow drain-back issue which shouldn't be the case but? and to state the obvious did you consider re-bleeding the filter head. I don't mean to state the obvious but to give a starting point.

I know a lot of people just use the technique of squirting the fuel from the bleed nipple onto a cloth or paper towel but after years of working with diesels that were much harder to bleed than this little unit I always use an uphill run of clear tube into a container so I can keep an eye on any air bubbles that might be present and prime until totally clear.

That fuel issue is what I'd be inclined to look at first - it then kind of implies electrical issues creeping into the mix but seems too much of a coincidence that it is after the new filter was installed.
If I remember correctly you are in Argentina - is it colder? That could amount for the need foe extra cranking.
Good luck.

hgrimberg · **Joined:** Mon Dec 19, 2011 11:03 pm **Posts:** 363

Auberon wrote:

Thanks. I presume you've checked everything for tightness to do with the filter installation, that is. It kind of sounds like you have a slow drain-back issue which shouldn't be the case but? and to state the obvious did you consider re-bleeding the filter head. I don't mean to state the obvious but to give a starting point.

I know a lot of people just use the technique of squirting the fuel from the bleed nipple onto a cloth or paper towel but after years of working with diesels that were much harder to bleed than this little unit I always use an uphill run of clear tube into a container so I can keep an eye on any air bubbles that might be present and prime until totally clear.

That fuel issue is what I'd be inclined to look at first - it then kind of implies electrical issues creeping into the mix but seems too much of a coincidence that it is after the new filter was installed.
If I remember correctly you are in Argentina - is it colder? That could amount for the need foe extra cranking.
Good luck.

Thank you Auberon! I'll try bleeding the fuel filter, I found this video which is an awesome explanation.
http://www.youtube.com/watch?v=qPwGcWi3gE0
I live in Argentina, which is very cold but this time of the year is summer time and we had exceptionally hot days lately.

Check engine light - Random/Multiple Cylinder Misfire?

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