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Ask Pete Your Own Question
Pete, Technician
Category: Jeep
Satisfied Customers: 28246
Experience:  Over 17 years diagnosing and repairing automobiles various makes and models with some training and certifications.
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Hey Pearl, how are you? JA: Sometimes things that you think

Customer Question

Hey Pearl, how are you?
JA: Sometimes things that you think will be really complicated end up being easy to fix with Jeep. The Jeep Mechanic I'm going to connect you with knows all the tricks and shortcuts.
Customer: okay
JA: Tell me a bit more about what's going on so he can help you best.
Customer: I have a couple code, P0300 and P2305. I know they are misfires but I changed all the spark plugs ignition coil and wires and I still have the codes and the vehicle is running rough. Cylinder #5 doesn't have no spark
JA: Spark plug problems can be challenging. So many causes, some simple, some complicated. Fortunately, the mechanics we work with have tons of experience dealing with all of them. Are you hoping to fix this yourself?
Customer: Is a 2009 Wrangler with a 3.8Liter engine
JA: Is there anything else important you think the Jeep Mechanic should know about your Jeep?
Customer: I just got it two months with 91,000 miles
JA: OK. Got it. I'm sending you to a secure page on JustAnswer so you can place the $5 fully-refundable deposit now. While you're filling out that form, I'll tell the Jeep Mechanic about your situation and then connect you two.
Submitted: 1 year ago.
Category: Jeep
Customer: replied 1 year ago.
I have a 2009 Wrangler with a 3.8liter engine. I was driving to an appoint going 55mph when the vehicle started shaking very roughly that I had to pull over. At first I thought my driveshaft broke but even while the vehicle was in park it was still idling rough. came to find out that it is a misfire. I have a couple codes a p0300 and p2305. I did a full tune up but the codes remain. Checked cylinder #5 and there isn't any spark at all on #5. I know this Jeep calls for copper plugs so I replaced the plugs with copper plugs
Expert:  Pete replied 1 year ago.
Hi my name is ***** ***** I will be happy to assist with this today.In some cases I may need more info to assist better.I apologize for any delay. If the #5 spark plug is not receiving spark and all others are and you have replaced the coil and wires this can be an issue with broken/damaged wiring to the ignition coil itself needing repaired or replaced.If you have not inspected all wiring leading to the coil pack I would see if any issues are found with wiring causing this fault.P0300 is a general misfire code.P2305 is a code for ignition coil 2 secondary circuit fault.Make sure fuse M19 (30 amp) is good in the integrated power module fuse panel.If this is o.k. and if there are no issues with the wiring between the PCM and coil then the PCM itslef can be at fault internally with the coil 2 control circuit with the PCM needing replaced. If more help is needed, use the reply tab to continue our conversation. If no further assistance is needed, kindly rate my service.You can rate at any time and we can continue to work on your question as this will not close out your question.Keep in mind in some cases it can be difficult to fully diagnose or help repair your vehicle without seeing it and I work on delivering the best possible answer from what I see to work with.Thanks Pete
Customer: replied 1 year ago.
Well fuse in the 19 m spot is good and the battery was weak so I replaced it. Anything else I can try before the pcm
Expert:  Pete replied 1 year ago.
Do you have a test light or multi meter?
Customer: replied 1 year ago.
Customer: replied 1 year ago.
The coil ground work is good too
Expert:  Pete replied 1 year ago.
Test the fuse to see if one terminal has power with the key on or off and let me know. Thanks Pete
Customer: replied 1 year ago.
Power only in the on position
Expert:  Pete replied 1 year ago.
At the ignition coil in terminal 4 at the connector do you have any ground or power signals (solid or fluctuating) with the engine running at all.This should be a dark blue/tan wire.
Customer: replied 1 year ago.
It won't run with that disconnected right?
Expert:  Pete replied 1 year ago.
Correct,I have located the diagnostic procedure on this here for testing.If you follow this chart it will lead you to the fault. When Monitored: Engine running and battery voltage greater than 10 volts. - Set Condition: If PCM detects that the secondary ignition burn time is incorrect, too short, or not present, an error is detected. One Trip Fault. Three good trips to turn off the MIL. ACTIVE DTC NOTE: Diagnose any ASD related DTCs before continuing. 1. Start the engine. 2. With a scan tool, select View DTCs. NOTE: It may be necessary to drive the vehicle to meet the conditions to set this DTC, try to repeat the conditions in which the fault originally set by reviewing the Freeze Frame data. Is the DTC Active at this time? Yes - Go To 2 No - Refer to the INTERMITTENT CONDITION Diagnostic Procedure.2. (F342) ASD OUTPUT CIRCUIT Turn the ignition off. 2. Disconnect the Ignition Coil harness connector. 3. Ignition on, engine not running. 4. Using a 12-volt test light connected to ground, probe the (F342) ASD Output circuit in the Ignition Coil harness connector. NOTE: Make sure the test light is probing the circuit before actuating the Coil or a DTC may set and not allow the actuation. 5. With a scan tool, actuate the ASD. Does the test light illuminate brightly? Yes - Go To 3 No - Repair the open or short to ground in the (F342) ASD Relay Output circuit between the TIPM and Coil harness connector.NOTE: Stop All Actuations.3. IGNITION COIL When the engine is operating, do not stand in direct line with the fan. Do not put your hands near the pulleys, belts or fan. Do not wear loose clothing. Failure to follow these instructions may result in possible serious or fatal injury. 1. Using a 12-volt test light connected to a 12-volt source, probe the (K17) Coil Control 2 circuit. 2. Crank the engine for 5 seconds while observing the test light. What is the state of the test light during the actuation? Brightly blinking. - Replace the Ignition Coil.ON constantly. - Go To 4 OFF constantly. - Go To 54. (K17) COIL CONTROL 2 CIRCUIT SHORTED TO GROUND Turn the ignition off. 2. Disconnect the C2 PCM harness connector. 3. Measure the resistance between ground and the (K17) Coil Control 2 circuit in the Coil harness connector. Is the resistance below 100 ohms? Yes - Repair the short to ground in the (K17) Coil Control 2 circuit.No - Go To 65. (K17) COIL CONTROL 2 CIRCUIT OPEN Turn the ignition off. 2. Disconnect the C2 PCM harness connector. CAUTION: Do not probe the PCM harness connectors. Probing the PCM harness connectors will damage the PCM terminals resulting in poor terminal to pin connection. Install PCM Pinout Box 8815 to perform diagnosis. 3. Measure the resistance of the (K17) Coil Control 2 circuit from the Coil harness connector to the appropriate terminal of special tool #8815. Is the resistance below 5.0 ohms? Yes - Go To 6 No - Repair the open in the (K17) Coil Control 2 circuit.6. POWERTRAIN CONTROL MODULE (PCM) 1. Using the wiring diagram/schematic as a guide, inspect the wiring and connectors between the Ignition Coil and the Powertrain Control Module (PCM). 2. Look for any chafed, pierced, pinched, or partially broken wires. 3. Look for broken, bent, pushed out or corroded terminals. Verify that there is good pin to terminal contact in the Ignition Coil and the Powertrain Control Module connectors. 4. Search for any Technical Service Bulletins that may apply. Were there any problems found? Yes - Repair as necessary.No - Replace and program the Powertrain Control Module. Let me know if you need anything else and feel free to rate my help here. Thanks Pete