Any one run in to a P349D-64 DTC issue? I think the issue started after an oil change. Truck has about 114k on it . runs and drives great . Any help much appreciated. Not looking to bring it to a dealer @ 500 an hour, as i've been a mechanic my whole life and recently completed a mclaren full engine rebuild.

 

You may already have this information, but in the event it may help, following it a summary of the code from Chat GPT:

DTC Code: P349D-64 – Range Rover L405

Meaning:
- P349D – Cylinder 6 Deactivation Performance
- -64 – Circuit range/performance fault (electrical issue such as open, short to ground/power, or high resistance)

Possible Causes:
- Faulty cylinder deactivation solenoid (AFM/VAT) on cylinder 6
- Damaged/corroded wiring or connectors in the solenoid circuit
- ECM output driver fault
- Low battery voltage or voltage drops during start

Recommended Diagnostic Steps:
1. Check battery and charging system for voltage drop or instability.
2. Inspect solenoid wiring and connectors around cylinder 6.
3. Measure solenoid resistance and compare to factory specs.
4. Swap cylinder 6 solenoid with another cylinder to see if fault code moves.
5. Use diagnostic scan tool to perform live data analysis and active tests.

Resolution:
- Replace faulty solenoid if resistance is out of spec or fault follows solenoid.
- Repair or replace damaged wiring/connectors.
- If electrical components test fine, consider ECM update or replacement.

Summary:
P349D-64 indicates a cylinder 6 deactivation circuit issue, commonly traced to a bad solenoid or wiring fault. Prioritize voltage, wiring, and solenoid testing to isolate the root cause.

 

I would also check the battery, and the ground on the car. If the battery is old or original, it can definitely throw weird codes at times. These cars are extrmely power hungry and a solid battery is a must. As mentioned above, that specific code points to a cylinder activation error, but you state that the car runs perfectly. Start with the easy battery stuff and keep us posted. Good luck.

 

funny i was thinking the same thing. im dropping down to 8 volts during crank.