2015 Jeep Cherokee Flashing Check Engine Light: A Bad Fuel Injector and an Unexpected Oil Leak
A 2015 Jeep Cherokee Limited arrived at our west location on Rambling Oaks Drive in Norman, Oklahoma, with a flashing check engine light and an engine that was stuttering and vibrating. Diagnostic testing identified an electrical problem involving the number six fuel injector. During the related service work, our PROFIX Auto Repair team also discovered a separate oil leak that needed attention.
A Flashing Check Engine Light and an Engine That Wouldn't Run Smoothly
The customer described an engine that stuttered and vibrated, initially while idling and eventually while driving. The check engine light was also flashing.
A flashing check engine light deserves prompt attention. It can indicate an active engine misfire, which may allow unburned fuel into the exhaust system and potentially damage the catalytic converter.
The first step was determining why this Cherokee's 3.2-liter V6 wasn't operating normally.
A diagnostic scan retrieved trouble code P0206 — Fuel Injector 6 Circuit/Open.
That was an important clue, but not a complete diagnosis.
What Does Trouble Code P0206 Actually Mean?
P0206 indicates that the vehicle's powertrain control module has detected a problem in the electrical circuit associated with fuel injector number six.
Fuel injectors deliver precisely controlled amounts of fuel into the engine. When an injector or its electrical circuit isn't functioning correctly, the affected cylinder may not receive the fuel it needs for proper combustion.
However, an injector circuit code doesn't automatically mean the injector itself needs replacement.
A wiring problem, poor electrical connection, or internal injector fault may produce similar symptoms. Additional testing helps distinguish between those possibilities.
For this Cherokee, the technician performed electrical resistance testing to evaluate the injector.
The Multimeter Readings Told the Story
According to the technician's diagnostic findings, the expected injector resistance for this test was approximately 10–16 ohms.
An ohm is a unit of electrical resistance. Measuring resistance provides information about the condition of an injector's internal electrical winding.
The results were revealing.
The number five fuel injector measured 14.6 ohms, within the expected range.
The number six fuel injector measured 35.9 ohms, considerably higher than expected.
That abnormal measurement, combined with the stored P0206 code and the customer's symptoms, supported the diagnosis of a faulty number six fuel injector.
Rather than replacing an injector based solely on a trouble code, the technician had documented electrical evidence supporting the repair recommendation.
Gaining Access to the Fuel Injector and Spark Plugs
With the injector fault identified, the customer approved replacement of the number six fuel injector along with all six spark plugs.
On the Cherokee's 3.2-liter V6 engine, access to some of these components requires removing intake system components. The repair plan also included the appropriate replacement gaskets and seals associated with the work.
The photographs from this job show the engine partially disassembled and the intake manifold removed for access.
This is one reason even a repair involving a single fuel injector can require considerably more work than the size of the component might suggest.
An Unexpected Discovery: Oil in the Spark Plug Tubes
During the spark plug service, the technician discovered a substantial amount of engine oil in the rear spark plug tubes.
This was a separate concern from the electrical problem involving fuel injector number six.
Spark plug tubes provide access to the spark plugs and accommodate the ignition coil boots. Engine oil should not be collecting in these areas.
When seals deteriorate, oil can enter the spark plug wells and coat the ignition coil boots. This contamination can create additional ignition-related problems and deserves attention, even when the engine originally came in for another concern.
The technician documented the oil accumulation and recommended replacing the right-side valve cover gasket to address the suspected sealing problem. The customer also approved that work.
The removed ignition coils provided another clear view of the oil contamination.
As shown below, oil was visible along the coil assemblies and on the shop towel beneath them.
Although the contamination was significant, it is important to distinguish the presence of oil from a confirmed ignition coil failure. The repair findings documented the oil problem without establishing that the ignition coils themselves required replacement.
One Visit, Two Different Engine Problems
This Cherokee's visit illustrates why careful diagnostics and inspection matter.
The original complaint involved a flashing check engine light and a rough-running engine. Electrical testing provided evidence identifying the number six fuel injector as the source of the injector circuit fault.
During the related service work, the technician also discovered oil where it didn't belong, leading to a separate valve cover gasket recommendation.
These were two distinct findings, each requiring its own explanation and repair approach.
The approved repair plan included replacing the faulty fuel injector, servicing the spark plugs, and addressing the valve cover gasket issue.
The important lesson is that a diagnostic trouble code is a starting point. Testing helps determine what actually needs attention, while a thorough inspection can reveal other conditions before they become larger problems.
Experiencing a Flashing Check Engine Light?
If your vehicle is running roughly, hesitating, vibrating, or displaying a flashing check engine light, it's important to have the underlying problem diagnosed rather than relying on the code alone.
At PROFIX Auto Repair, we provide engine diagnostics, electrical testing, fuel injector service, and mechanical repairs at our west location on Rambling Oaks Drive in Norman.
Our east location, Leon's PROFIX Auto Repair on North Porter Avenue, provides these services as well.
Whether you visit us on the east or west side of Norman, our goal is to help you understand what's happening with your vehicle and recommend repairs based on what testing reveals.
Use the Book Online button for your preferred location below, or send us a message through our contact form.
PROFIX Auto Repair – West
1121 Rambling Oaks Dr
Norman, OK 73072
📞 (405) 310-2279
🕒 Monday–Friday: 7:30 AM – 5:00 PM
Leon’s PROFIX Auto Repair – East
521 N Porter Ave
Norman, OK 73071
📞 (405) 364-2799
🕒 Monday–Friday: 7:30 AM – 5:00 PM
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