Easy one-page printout for the garage or repair shop
This summary uses the existing diagnostic information shown in full below.
This code means that the car's computer is having trouble understanding the engine's position when you start the car. It's like trying to read a book with missing pages.
The code indicates that the engine control module (ECM) is receiving inconsistent signals from the high-resolution timing sensor during the engine start-up process.
P139D is set when the ECM detects erratic or intermittent signals from the high-resolution timing sensor 'A' during engine start. This sensor provides precise information about the crankshaft's position, which is essential for proper ignition timing and fuel injection.
• Engine may be hard to start
• Check Engine Light illuminated
• Poor engine performance
• Faulty high-resolution timing sensor
• Damaged or corroded wiring/connectors
• ECM software issue
ECM: Engine Control Module
OBD-II: On-Board Diagnostics, Second Generation
• Check for any stored trouble codes
• Inspect the wiring and connectors of the timing sensor
• Test the timing sensor for proper operation
• Replace the faulty timing sensor
• Repair or replace damaged wiring/connectors
• Update ECM software if necessary
• OBD-II scanner
• Multimeter
• Basic hand tools
$150 - $400
Moderate
• Chevrolet Silverado
• Ford F-150
• Dodge Ram
• Regularly check and maintain engine sensors
• Ensure wiring and connectors are in good condition
• Keep ECM software updated
Sensor Issue
• Do not ignore the Check Engine Light
• Have the vehicle diagnosed by a professional
• Avoid driving the vehicle if starting issues persist
Check with your vehicle manufacturer for warranty coverage on engine sensors.
This code has been associated with engine starting issues in various models, often related to sensor or wiring problems.
Moderate – While the vehicle may still run, it could lead to more serious issues if not addressed.
Driving with a malfunctioning engine sensor may lead to increased emissions and potential engine damage.
• Engine must be cold
• Ensure battery is fully charged
The high-resolution timing sensor is typically located near the crankshaft or camshaft, depending on the vehicle model.
Q: Can I drive with a P139D code?
A: It's not recommended to drive for extended periods with this code, as it may lead to more serious engine issues.
Q: How do I reset the Check Engine Light after fixing the issue?
A: Use an OBD-II scanner to clear the code after the repair is completed.
High-End · Full-system diagnostics
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Network faults often require full-system access instead of a generic code reader alone.
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Universal · Digital multimeter
A solid entry-level multimeter for voltage, continuity, resistance, and basic electrical troubleshooting.
Helpful for checking voltage drops, grounds, and basic circuit health when modules are not communicating.
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Universal · Wire connectors and repair kit
Useful when diagnosis points toward damaged wiring, corroded terminals, or connector repairs.
Useful if diagnosis points toward damaged connectors, wiring, or terminal repairs.
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Fitment Required · Vehicle-fitment part
Commonly relevant for misfire, ignition-efficiency, and some drivability-related repairs.
Misfire and ignition-related faults commonly involve spark plugs as part of the repair path.
Check the correct plug type, gap, and engine application for your vehicle.
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Fitment Required · Vehicle-fitment part
Relevant when the fault points toward ignition-coil performance or cylinder-specific ignition issues.
Some ignition faults involve coil performance or cylinder-specific coil problems.
Match the coil to your engine and confirm the failed component before ordering.
View options on AmazonThese parts may be related to this fault category, but a code by itself does not confirm exact fitment or guarantee that replacing a part will solve the problem.