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2006 GC LTD
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Discussion Starter · #1 ·
2006 JGC Limited, 5.7 Hemi. Hello all, I'm getting to the bottom of the troubles with this Cherokee finally. A brief history is I bought it late last year, had some CEL and start and die symptoms. Dealership found lean condition in bank 1 and 2. I'm not entirely sure what that means but they thought it was the exhaust manifolds and broken manifold bolts/studs. They cleared the codes and somehow it stuck, no more CEL, no more start and die symptom. I haven't done anything to the exhaust, I figured the CEL would be back soon. When the light didn't come back I set my attention to other maintenance, CV shafts, brakes, wheel bearings, fluids in the drivetrain and motor. Empowered by several threads on cleaning the throttle body I dove in. Starting with disconnecting the battery.

From the second I started it after that I have had lots of flashing lights and crazy idling. I have done the TB "relearn" procedure many times now, always successfully for a while. During an hour drive yesterday the TB light and the traction control light came on 3 times. Each time I'd pull over and relearn the TB, all systems go, except the CEL staying on. When the TB light is flashing I can lose all throttle input, encounter major surging of the throttle, or some pretty bad shuddering of the entire vehicle. When I got home I did the key dance and pulled the DTCs. Here they are with some generic definitions I found.

P0171System too lean Bank1
P0174System too lean Bank2
P0113Intake Air Temp High Input Bank1
U0114Lost Communication with 4WD Clutch Control Module
P2173Throttle Actuator Control System High Air Flow
P2118Throttle Actuation Control Module Current Range
P2110Throttle Actuation Control System Forced Limit RPM

I'm thinking disconnecting the battery cleared the computer and whatever tricks the dealership had done with their scan tool because this is about how it was acting before I took the vehicle back to them. The starting and dying I was experiencing when I first bought the Jeep was the same surging idle I have now. Sometimes the surges spike and drop so wildly that the engine will die. The codes tell me I still have the lean banks, the TB isn't happy, seemingly from a voltage issue, and the FWDCCM is having an issue. Seems to me like I may be looking for a loose or broken wire? I have read about vehicle speed sensors causing issues, as well as broken wires inside the differentials. My battery is fully charged, though I haven't load tested it myself. Sorry if this is tough to follow, it's hard to keep all the facts straight and rush to type this up while the little one naps.:D Also I'm sure I'll get grilled about cleaning the TB wrong, and I can accept that possibility as it is the first time I have had this one apart, but all I did was lightly break up the thickest bits of carbon with a dull screwdriver so as not to scratch anything, and spray a rag lightly with seafoam to wipe up the residue. I made certain to avoid any chance of the chemical getting into the electronics. Also if the TB were hashed would I be able to relearn it and get 20 minutes of normal driving out of it?

I guess that's it for now, thanks for reading along with me. :thumbsup:
 

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2006 GC LTD
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Discussion Starter · #2 ·
I remembered seeing the TB wires looking kinda rough so I thought I'd inspect them closer. The aluminum below the wires where they live has a black mark left from the wiring harness protective wrap where the engine cover must have pressed the wiring down, and it had to bend back up sharply to plug into the TB. The Jeep was sold to me without an engine cover so I can't be certain about that, but the wires themselves are kinked in the same spot. I ohm tested each wire and they all seemed in tact. That old wire wrap was baked and brittle so I wrapped them with some new stuff. I found some electrical tape wrapped around an inch or so of the yellow wire running to the front drivers side coil, I think it is. I unwrapped it and there is a slice taken off the sheathing down to bare wire. The wire doesn't seem interrupted. Seems like someone needed access to that wire, perhaps for checking the timing? Anyhow, before probing the wires for the ohm check I disconnected the battery again so this time all codes were gone and it was a fresh start. I did a quick relearn on the throttle body then ran down to town to get gas. Everything was normal and as I was leaving the gas station the CEL came on again. I pulled the codes when I got home and was surprised to only find P0507-Idle Control System RPM Higher than Expected. I don't think it's done throwing codes, but further driving will have to wait.
 

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2006 WK Overland
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Sounds like you have your hands full. A couple things first:
--How many miles on the vehicle?
--Have you checked the condition of the battery? You should do both a conductance test, which takes about 5 seconds, and a load test, which takes about 10 seconds. Once the battery is confirmed good, you can go on.
--Have you hooked a good computerized scanner up to it? This would be helpful, as you can then see what is really happening and, in most cases, operationally check some of the components we're talking about here.......O2 Sensor operation, FDCM status, Throttle Body Follower Test, etc.

After the above is done, disconnect the battery and then I'd remove, inspect and clean the 4 plugs on the PCM/TCM. Inspect all wiring and pins for condition and proper placement in the plugs. Check the IAT plug, IAT Sensor for damage and inspect the wiring, and reinspect the Throttle Body wiring and plug......go back about 10 inches or so on all plugs. Along these lines, also check the wire bundle routing for taut/chaffing wires that could be damaged and/or intermittent. Check or have checked at a muffler shop for exhaust leaks, especially at the exhaust log manifolds. Check around the intake manifold for vacuum leaks, especially where the tube from the EGR Valve enters the intake and also the Purge Valve Vacuum line. Both are right behind the Throttle Body. Also, check to make sure the PCV Valve (and hose from valve to intake manifold) and MAP Sensor are in good condition and properly installed. Finally, fix or have fixed any problems that you find, clear all codes and try it again. If the problem(s) persist, below, from the FSM, are some of the potssible causes of the Diagnostic Trouble Codes you indicated above:

P0171 and P0174

Possible Causes
RESTRICTED FUEL SUPPLY LINE
FUEL PUMP INLET STRAINER PLUGGED
FUEL PUMP MODULE
O2 SIGNAL CIRCUIT
O2 RETURN CIRCUIT
O2 SENSOR HEATER OPERATION
O2 SENSOR
MAP SENSOR OPERATION
ECT SENSOR OPERATION
ENGINE MECHANICAL
FUEL FILTER/PRESSURE REGULATOR (HIGH)
PCM

P0113

Possible Causes
(K21) IAT SIGNAL CIRCUIT SHORTED TO BATTERY VOLTAGE
(K21) IAT SIGNAL CIRCUIT OPEN
(K900) SENSOR GROUND CIRCUIT OPEN
IAT SENSOR
PCM

U0114

Possible Causes
CAN B OR CAN C BUS CIRCUITS OPEN OR SHORTED
DTCS RELATED TO BATTERY VOLTAGE, IGNITION, OR VIN MESSAGES
FCM NOT CONFIGURED CORRECTLY
FINAL DRIVE CONTROL MODULE POWER AND GROUND
FINAL DRIVE CONTROL MODULE
MODULE THAT SET THIS DTC

P2173

Possible Causes
VACUUM LEAK
RESISTANCE IN THE (F856) 5-VOLT SUPPLY CIRCUIT
(F856) 5-VOLT SUPPLY CIRCUIT SHORTED TO GROUND
RESISTANCE IN THE (K1) MAP SIGNAL CIRCUIT
(K1) MAP SIGNAL CIRCUIT SHORTED TO GROUND
RESISTANCE IN THE (K900) SENSOR GROUND CIRCUIT
RESISTANCE IN THE (F855) 5-VOLT SUPPLY CIRCUIT
(F855) 5-VOLT SUPPLY CIRCUIT SHORTED TO GROUND
RESISTANCE IN THE TP SENSOR SIGNAL CIRCUIT
TP SENSOR SIGNAL CIRCUIT SHORTED TO GROUND
RESISTANCE IN THE (K922) TP SENSOR RETURN CIRCUIT
MAP SENSOR
TP SENSOR
PCM

P2110

Possible Causes
THROTTLE PLATE STUCK
(K124) ETC POSITIVE CIRCUIT OPEN
(K126) ETC NEGATIVE CIRCUIT OPEN
(K124) ETC POSITIVE CIRCUIT SHORTED TO GROUND
(K126) ETC NEGATIVE CIRCUIT SHORTED TO GROUND
ETC MOTOR
PCM

P2118

Possible Causes
THROTTLE PLATE / BORE INSPECTION
(K124) ETC POSITIVE CIRCUIT SHORTED TO BATTERY VOLTAGE
(K126) ETC NEGATIVE CIRCUIT SHORTED TO BATTERY VOLTAGE
(K124) ETC POSITIVE CIRCUIT SHORTED TO THE (K126) ETC NEGATIVE CIRCUIT
(K124) ETC POSITIVE CIRCUIT OPEN
(K124) ETC POSITIVE CIRCUIT SHORTED TO GROUND
(K126) ETC NEGATIVE CIRCUIT OPEN
(K126) ETC NEGATIVE CIRCUIT SHORTED TO GROUND
ETC MOTOR
PCM

P0507

Possible Causes
AIR INDUCTION SYSTEM
VACUUM LEAKS
THROTTLE BODY
PCM

Do all troubleshooting from easy/inexpensive to more difficult/expensive. Verify any component failure, if possible, before buying parts. Good luck and keep us posted on your findings.
 
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2006 GC LTD
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Discussion Starter · #4 ·
"--Have you hooked a good computerized scanner up to it? This would be helpful, as you can then see what is really happening and, in most cases, operationally check some of the components we're talking about here.......O2 Sensor operation, FDCM status, Throttle Body Follower Test, etc."

Thank you sir, I really appreciate the detail you've given to help me out. I saw where you recommended @$700 scan tool in another post, Autel was it? I searched for it and found the baby brother to it, the MD808P. It seems to tick all the boxes for me especially being a shade under half of the price point for the one you have. Can I ask your opinion on whether or not this scan tool will get me anywhere? If the MD808P isn't going to cut it then I will have to take the Jeep to someone. I'd much rather do it myself.

https://www.amazon.com/gp/product/B0714GBRZK/ref=ask_ql_qh_dp_hza

Also mileage is around 189K, and I will get my battery checked out this week. Thanks again.
 

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2006 WK Overland
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A good scanner, like most test equipment, should give you a pretty good idea of what is going on in all the systems that it covers. Also, being able to functionally check the operatiion and, in some cases, calibrate components can be useful. The $$$ saved from one or two stealer trips , in some cases needless ones, would easily pay for a good scanner, plus ones like this will work on any '96 and later OBDII equipped vehicle, not just your Jeep. Also, be aware that there will be features and acronyms that you won't know or understand anything about. I found plenty with the DS708 and even more with my current scanner.

I looked a bit, as good as I could find on line, the features of the MD808/MD808 Pro and found that it appears to be a pretty decent scanner. I couldn't tell if it would allow some of the items to be tested, observed/monitored, calibrated though.....electronic throttle control follower test, FDCM active tests/live data, cam/crank sensor relearn, etc. to name a few. Perhaps a little more research will allow you to get more info. You may want to look at the Autel website, as they usually have pretty good info.

The tester I used to have was an Autel DS708, which I have since given to my son. I now have an Autel MS906, which is a little more sophisicated yet than the DS708. If you're after something like the DS708, I've seen used ones on line that sell for half or less than the original price. The cautions I would use if thinking of purchasing something like this are:
--Be sure it has been updated (On mine I had installed updates for every typevehicle I may ever encounter.)
--Use nothing but Paypal to pay for it. That way, if there is a problem of some sort, they'll cover it.
--If you use Ebay, make sure they're a highly rated seller.

Good luck.
 
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