P2673 — Injection Pump Timing Calibration not Learned #

Note: The wording of this DTC (Diagnostic Trouble Code) may vary depending on the vehicle manufacturer (OEM). Always refer to your specific service manual for exact definitions.

• Injection Pump Timing Calibration Not Performed (Ford)
• Fuel Pump Timing Not Learned (GM)
• Injection Timing Adaptation Not Completed (Mazda)
• Injection Pump Timing Self-Learning Incomplete (Toyota)

Summary of code P2673 #

The P2673 code is triggered when the PCM (Powertrain Control Module) detects that the injection pump timing calibration has not been learned or completed successfully. The injection pump is a key component in diesel engines, responsible for delivering fuel to the engine’s cylinders at precise intervals. When the timing calibration isn’t learned, it means that the engine control system cannot accurately control fuel injection events, which may impact performance and emissions. This code often appears after a pump replacement, timing adjustment, or repair where the calibration process was skipped or unsuccessful. Some vehicles may illuminate the MIL (Malfunction Indicator Lamp) or show a message like “Service Engine Soon.”

Common symptoms for code P2673 #

If your vehicle registers a P2673 code, you’ll likely notice a combination of drivability issues, though sometimes the symptoms can be subtle—especially when the code is a result of a recent repair or calibration procedure that wasn’t finished. Watch for the following:

• Check Engine Light or other warning lights illuminated
• Rough or unstable idle
• Engine hesitation or misfire during acceleration
• Decreased fuel efficiency
• Hard starting, especially when the engine is cold
• Loss of engine power or limp mode activation

Likely causes for code P2673 #

The root causes of a P2673 code generally revolve around the calibration process or related components. Here’s what typically triggers this code, in order of likelihood:

1. Injection pump timing calibration not performed after repair or replacement
2. Faulty or incorrectly installed injection pump
3. Wiring or connector issues between the pump and PCM (corrosion, loose terminals, damaged wires)
4. Outdated or corrupted PCM/ECU software
5. Mechanical timing issues (timing belt/chain skipped or misaligned)
6. Failed crankshaft or camshaft position sensors

Step-by-step diagnosis for code P2673 #

Diagnosing a P2673 code requires a systematic approach to avoid misdiagnosis and unnecessary repairs. Follow these steps:

• Connect a professional scan tool and verify the presence of P2673. Check for related codes (especially those relating to fuel injection, timing, or crank/cam sensors).
• Review freeze-frame data to understand the conditions when the code set.
• Inspect recent service history: Has the injection pump or timing system been serviced recently?
• Perform a visual inspection of the injection pump, connectors, and wiring for signs of damage or poor installation.
• Check the mechanical timing (timing belt or chain alignment) using OEM procedures.
• Attempt the calibration procedure using an OEM scan tool or equivalent, following the manufacturer’s instructions precisely.
• If calibration fails, test the crankshaft and camshaft position sensors for correct operation (scope or scan data).
• If all else checks out, check for PCM/ECU updates and reprogram if required.

Possible repairs for code P2673 #

Once you’ve identified the cause, repairs for P2673 should address the underlying issue. Typical fixes include:

• Performing the injection pump timing calibration as per OEM procedure
• Correcting the installation of the injection pump (reinstall or adjust as necessary)
• Repairing or replacing damaged wiring/connectors between pump and PCM
• Updating or reprogramming PCM/ECU software if a calibration bug is present
• Repairing or replacing mechanical timing components (timing belt/chain and related parts)
• Replacing faulty crankshaft or camshaft position sensors

Is it safe to drive with code P2673? #

Generally, it’s not recommended to drive for extended periods with code P2673 present. While the vehicle may still operate, improper injection timing can lead to rough running, hard starting, increased emissions, and potential long-term engine damage. If the vehicle is in limp mode or exhibits severe drivability issues, limit driving to short distances and address the problem as soon as possible.

Vehicles most commonly affected by code P2673 #

P2673 is most often seen in vehicles equipped with electronically controlled diesel injection pumps, especially after service or repairs. While not exclusive, the following makes and models are frequently associated with this code:

• Ford Super Duty trucks (F-250, F-350, F-450 with Power Stroke)
• Chevrolet/GMC Duramax diesel pickups
• Ram trucks with Cummins diesel engines
• Mazda BT-50 and diesel CX-5
• Toyota Hilux and Land Cruiser diesels
• Nissan Navara and Patrol diesels

Common mistakes & best practices for code P2673 #

It’s easy to misdiagnose P2673, especially if you skip key steps or overlook the importance of calibration. Here’s what to watch out for:

• Skipping the calibration procedure after repairs—always complete calibration after pump or timing work!
• Assuming a faulty pump when the real issue is an incomplete calibration or bad wiring
• Ignoring recent service history or not resetting learned values in the PCM
• Using generic scan tools that lack OEM calibration functions
• Not checking for PCM/ECU software updates that may resolve calibration bugs

FAQ express — P2673 #

Q: Can I clear the code and keep driving?
A: Clearing P2673 without performing the proper calibration will almost always cause the code to return. The underlying issue must be addressed for a permanent fix.

Q: Is this code always caused by a bad injection pump?
A: No. In fact, most cases relate to missed or incomplete calibration steps, wiring problems, or sensor issues. Replacing the pump without diagnosing the true cause can lead to unnecessary expense and frustration.