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Vehicle has code for P06DD engine oil pressure control circuit performance/stuck off and goes into limp mode. Engine is Chrysler 2.0L multiair with dual stage oil pump, approximately 25k miles. This is a problem car with multiple repairs for same code, no drivability concerns and no obvious indication of engine mechanical failure.
Diagnostic sheet points towards wiring issue as most likely cause and oil pump being last resort. Checked connectors for looseness or damage, pin drag felt normal no corrosion or visible concerns. Harness showed no signs of damage. Checked oil pump control circuit. Based on diagram, PCM should feed voltage to solenoid which then goes to ground. Measured 0.4 ohms resistance between PCM and solenoid, 0.4 ohms from solenoid directly to chassis ground. Grounded both sides of the control circuit and checked with test light - bulb was bright and showed no wire integrity concerns. Actuated the solenoid via scan tool, can hear it clicking and measured battery voltage at the solenoid. With engine running, measured battery voltage at idle and 0V when blipping throttle or above 3000 RPM. Everything working like it should so far and no reason to suspect circuit fault or am I missing something??
This vehicle has no other codes, oil pump replaced, pressure sensor swapped, multiple oil and filter changes. Mechanical pressure gauge matches sensor and live data recording shows oil pressure within spec throughout RPM range - low and high pressure mode status in sync with RPM and pressure changes.
I've ran a separate wire from the PCM directly to the solenoid and gave it a dedicated ground just to rule out a potential harness issue and so far the fault has not come back yet and that concerns me as I was pretty confident with my wiring check but if the car continues to drive without the code triggering I must've made a mistake somewhere?
Measured resistance of the ground side circuit from pin straight to chassis. Wiring diagram shows ground circuit terminates at a ground point on the body near the firewall. Assumed grounding my lead to anywhere on the chassis would be okay and 0.4 ohms would indicate a good path to ground.
FCA requires wire load test following resistance checks so I put my test light to that same ground pin, bulb lit up bright - no indication of wire integrity concerns on that side. Next I jumped the other pin to ground and put my test light to the PCM connector to check power side, again test light lit up bright so naturally I assumed the control circuit itself is okay.
From the service information high pressure mode operates above 3000 rpm so what I saw was normal operation and that check was performed on the hoist. I can run the car all day in the shop and it would never set a code, only under load.
I've since ran a dedicated ground for that solenoid and so far the code hasn't come back yet. I am almost positive there is a problem with the engine harness but not able to pinpoint where. There are a dozen different components sharing that same ground circuit and multiple ground terminations.
