CAT Engine 27313 Fault Code: Turbo Outlet Pressure calibration required
Also called Turbo Out Press Signal Out of Calibration, Turbo Outlet Pressuer Sensor Calibration, Turbo Outlet Pressure Calibration Required, Turbocharger Outlet Pressure Sensor Calibration Required, Turbocharger Outlet Pressure Sensor calibration required
Turbo Outlet Pressure calibration required · ai-assisted, editor-reviewed · Last updated 2026-07-13
TL;DR
Code 27313 means the CAT ECM could not complete its automatic calibration of the turbocharger outlet (boost) pressure sensor against the atmospheric pressure sensor. It applies to C15 and C27 engines, shows as an active code (not logged in memory), and affects available power until it clears.
Medium severity. The code causes a low power condition but is not an immediate engine-damage event. It should still be diagnosed promptly because boost pressure feeds the ECM's fuel/air ratio control, and running with an uncalibrated or faulty sensor can mean incorrect fueling under load.
What does CAT Engine error code 27313 mean?
The turbo compressor outlet pressure sensor tells the ECM what boost pressure the turbocharger is producing. The ECM uses that signal to help control the air/fuel ratio during acceleration, similar to how a mechanical governor would limit fuel based on manifold pressure. If this sensor's signal cannot be trusted, the ECM cannot properly limit fueling, so it displays 'Turbo Out' as Invalid Data and logs code 27313 as an active fault.
Every time the ECM is powered up and the engine stays off for a set warm-up window, the ECM runs an automatic calibration of all its pressure sensors, checking each one against the atmospheric pressure sensor. If the turbo outlet sensor reading falls outside the acceptable range, varies too much during the check, or doesn't match atmospheric pressure closely enough, the calibration fails and 27313 sets. Because this is a calibration check, the code is active only while the fault condition exists and is not stored in permanent fault memory.
This code is closely tied to sensor supply and wiring health. The sensor runs on a regulated 5.0 volt DC supply from the ECM and returns a variable signal voltage that the ECM converts into a pressure reading. Problems anywhere in that supply, return, or signal circuit can prevent a valid calibration.
What triggers a CAT Engine 27313 code?
The ECM will set 27313 if any of these conditions occur during a calibration attempt: the turbo outlet pressure sensor has never been calibrated, the outlet pressure reads below 35 kPa (5 psi), the outlet pressure reads above 122 kPa (18 psi), the outlet pressure fluctuates more than 10 kPa (1.5 psi) during the attempt, the outlet pressure differs from atmospheric pressure by more than 15 kPa (2 psi), or an active diagnostic code with an FMI of 03 or 04 is already present on this sensor. One version of the logic also lists a narrower acceptable band, requiring the sensor to read greater than 35 kPa (5 psi) and less than 125 kPa (18 psi), and within 15 kPa (2.2 psi) of the atmospheric sensor. Calibration only runs if the ECM has been powered with the engine off for at least five seconds (one description) or ten seconds (another description); cranking the engine before that window elapses aborts the calibration attempt and the previous stored calibration value is used instead.
Common causes of 27313
- Connectors, pins, or sockets at the sensor or ECM that are damaged, corroded, or not fully seated
- Wiring harness damage including abrasion, corrosion, or pinch points, or a general problem in the harness
- Open or short circuit in the signal wire, including a short to ground or a short to the analog sensor common line
- Open circuit in the 5 volt supply wire, or a short between the 5 volt supply and the signal wire
- A faulty or out-of-range turbo outlet pressure sensor that needs to be replaced
- An incorrect sensor installed for this application
- A defective or faulty ECM that needs to be replaced
- An intermittent connection or wiring problem that only shows up under vibration or temperature change
- Leaks in the turbocharger outlet pressure system itself, which can prevent a true reading during calibration
How to troubleshoot CAT Engine 27313: first checks
- Connect a diagnostic scan tool (Cat ET or equivalent) and confirm whether 27313 is currently active, and check for any other active codes on the turbo outlet pressure sensor circuit with an FMI of 03 or 04, since these will block a successful calibration
- Inspect the sensor connector and ECM connector (J1/P1) for corrosion, bent pins, or a connector that is not fully latched
- Visually trace the harness between the sensor and ECM for chafing, pinch points, or corrosion, paying attention to the 5 volt supply pin, the sensor return/ground pin, and the signal pin
- With the key on and engine off, check the sensor's 5 volt supply and ground for correct voltage, and check the signal wire output for a valid varying DC voltage between 0.2 and 4.8 VDC, corresponding to the sensor's rated operating range of 33 to 326 kPa (4.8 to 47.3 psi)
- Check for leaks in the turbocharger outlet pressure system that could cause an inaccurate reading during the calibration window
- If wiring and connectors check out, swap or bench test the sensor itself to rule it out before condemning the ECM
How the code clears
No separate clearing step is listed beyond letting the ECM complete a successful automatic calibration. This happens on its own the next time the ECM is powered on and the engine is left off for the required warm-up period (five or ten seconds depending on the description) without cranking. If wiring, connector, or sensor problems caused the failed calibration, repairing or replacing the faulty component allows the next power-up cycle to calibrate successfully and the active code will clear on its own since it is not stored in permanent fault memory.
Affected models and serial ranges
27313 appears in our records across 2 CAT Engine models. Match your machine by model and serial number.
| Model | Serial ranges |
|---|---|
| C15 | Serial range not listed in source records |
| C27 | Serial range not listed in source records |
Frequently asked questions
What does CAT code 27313 mean?
It means the ECM's automatic calibration of the turbocharger outlet (boost) pressure sensor did not complete successfully. The ECM checks this sensor against the atmospheric pressure sensor every time it powers up with the engine off, and if the readings don't line up within the allowed range, the code sets as active.
Will 27313 stay stored in memory after I fix it?
No. This code is not logged into permanent fault memory. It only shows as active while the calibration failure condition exists. Once a successful calibration completes, the active code goes away on its own.
Does this code cause a loss of power?
Yes, the documented system response includes a low power condition. Because the ECM cannot trust the boost pressure signal, it cannot properly manage the air/fuel ratio limit under acceleration, so expect reduced power until it's resolved.
Why would a brand new ECM show this code?
A new, never-powered ECM has no previous calibration value stored, so it must complete a fresh calibration. If that first calibration attempt fails for any of the listed reasons, such as pressure out of range or fluctuating during the check, 27313 will set.
Can cranking the engine too soon cause this code?
Yes. If the engine is cranked before the ECM's required off-time window elapses (five or ten seconds depending on the version of the logic), the calibration attempt is aborted and the ECM falls back on the previous stored calibration value if one exists.
What's the difference between 27313 and other turbo outlet pressure sensor codes?
27313 specifically covers the calibration process failing, not a simple open or short circuit fault on the sensor. If there are already active codes on the sensor circuit with an FMI of 03 or 04 (open or short circuit type faults), those will prevent calibration and can trigger 27313 as well.
Is this a safety-critical fault?
It's not an immediate safety emergency, but it affects engine fueling control and power output. Treat it as a diagnose-soon issue rather than something to run past for an extended period, since incorrect air/fuel control can eventually stress the engine.