01 This Is How to Fix Sensor-Related Fuel Consumption Problems… • 02 The Risks of Driving at Low RPMs: How to Avoid Engine Damag… • 03 What Happens If You Drive a Keyless Car Without the Key? • 04 This Is Why Your Car Randomly Shakes At Idle Even Without W… • 05 What to Do If Your Car Only Starts When You Hit the Starter • 06 Understanding Overheating Issues in the Mazda CX-5 • 07 Mastering DC Motors: A Comprehensive Guide to Types, Operat… • 08 Is Expensive Oil Worth It? The Truth About Synthetic vs. Se… • 09 Engineers Share the Five Minute Secret That Keeps Vehicles … • 10 Why are not all tires on a car the same width? •

DTC codes / P06xx · Computer and output circuits / P064B

P064BPTO Control Module

P064B is a generic powertrain code that indicates the engine control module has detected a fault within the power take-off (PTO) control module circuit or its communication path. The PTO system allows auxiliary equipment to draw power from the engine, and this code sets when the control module receives implausible signals or loses communication with the PTO module.

SystemPowertrain
Code typeGeneric (all makes)
SeverityMedium
Fix difficultyIntermediate
AreaComputer and output circuits

Symptoms you may notice

  • Illumination of the check engine light or service engine soon light
  • PTO system fails to engage or disengage when commanded
  • Auxiliary equipment powered by the PTO does not operate
  • Reduced engine power or altered throttle response in some applications
  • Often no symptoms besides the warning light

Common causes, most likely first

  1. Faulty PTO control module or internal circuit failure
  2. Damaged or corroded wiring harness between the ECM and PTO module
  3. Blown fuse or poor ground connection for the PTO circuit
  4. Software or calibration error in the ECM or PTO module
  5. Water intrusion or connector corrosion at the PTO module
  6. Aftermarket PTO equipment improperly installed or incompatible

How to diagnose and fix it

  1. Verify the code with a scan tool and check for related codes in other modules
  2. Inspect the PTO circuit fuses and relays, replacing any that are blown or faulty
  3. Visually inspect wiring and connectors at the PTO module and ECM for damage or corrosion
  4. Perform a voltage drop test on the power and ground circuits to the PTO module
  5. Check for technical service bulletins or software updates for the PTO system
  6. If wiring and power are good, test the PTO module with a known-good unit or follow manufacturer diagnostics
  7. Clear codes and verify the repair with a test drive or PTO operation cycle

PTO module faults often misdiagnosed

  • A loose or corroded ground connection at the PTO module can mimic a failed module and is frequently overlooked during diagnosis.
  • Aftermarket PTO installations that tap into factory wiring can introduce interference or voltage spikes that set this code without any factory component failure.
  • The ECM may set P064B when communication on the controller area network (CAN) bus is disrupted by another module, so check for communication codes in all modules.
  • Some vehicles require a relearn or calibration procedure after replacing the PTO module, and skipping this step will cause the code to return.
  • A weak battery or charging system fault can cause low voltage to the PTO module, triggering this code even though the module itself is healthy.

Can I keep driving with P064B?

If the vehicle drives normally without the PTO engaged, it is generally safe to continue driving to a repair shop, but avoid using the PTO system until the fault is corrected. If the engine runs poorly or the PTO is needed for work, have the vehicle inspected promptly.

Tools that help

Tools we recommend are in the Auto Veteran shop on Amazon. As an Amazon Associate we earn from qualifying purchases.

Guidance is general and written for all OBD-II vehicles. Exact tests and values vary by model, so confirm the fault before replacing parts.

Running on fumes Free guides aren't free to make. Top up the tank. Any amount, one time. Fuel the Garage