CAT Engine 27513 Fault Code: Right Turbo Inlet Pressure calibration required
Also called Right Turbo Inlet Pressure Calibration Required, Right Turbocharger Inlet Pressure Sensor calibration required, Turbo Inlet Right Pressure Sensor Calibration, Turbo Right In Calibration
Right Turbo Inlet Pressure calibration required · ai-assisted, editor-reviewed · Last updated 2026-07-13
TL;DR
CAT fault code 27513 means the ECM tried to calibrate the right turbocharger compressor inlet pressure sensor against the atmospheric pressure sensor and the calibration failed. This is an active-only code on C27 engines, it is not logged in ECM memory, and it results in reduced engine power until it is resolved.
Medium severity. The engine keeps running but power is derated, and the air filter restriction system may be reporting invalid data. It should be diagnosed promptly, but it is not an immediate stop-the-engine emergency.
What does CAT Engine error code 27513 mean?
Code 27513 is tied to the automatic pressure sensor calibration the ECM runs on the right turbo compressor inlet pressure sensor every time the key is turned on. The ECM checks this sensor's reading against the atmospheric pressure sensor to make sure the two agree closely enough to trust the sensor's data going forward. If the readings do not line up within the allowed range, calibration fails and this code sets.
This sensor pairing is what the ECM uses to detect engine air filter restriction. If the turbo inlet pressure sensor cannot be trusted, the ECM cannot tell whether the air filters are actually restricted or not, so it treats the data as invalid and derates engine power as a protective measure.
The code is described as active only. It will show on the diagnostic lamp or a scan tool while the condition exists, but it is not stored in permanent ECM memory the way many other codes are.
What triggers a CAT Engine 27513 code?
Calibration is attempted during the first five seconds after the ECM is powered up (a separate note on the analog sensor calibration process states ten seconds), and only if the engine is not cranked during that window. For the calibration to pass, the sensor reading must be greater than 45 kPa (6.5 psi) and less than 115 kPa (16.7 psi), and it must be within 8 kPa (1.2 psi) of the atmospheric pressure sensor reading. A related version of this condition set lists failure when turbo inlet pressure is below 45 kPa (6.5 psi), above 111 kPa (16 psi), fluctuates more than 5 kPa (0.75 psi) during the calibration attempt, or differs from atmospheric pressure by more than 8 kPa (1.2 psi). Active diagnostic codes on the sensor at the time of calibration will also block a successful calibration. A separate short-to-ground condition sets when the ECM reads the right turbo compressor inlet pressure signal below 0.2 VDC.
Common causes of 27513
- Damaged, corroded, or loose connectors and wiring at the turbo compressor inlet pressure sensor or its harness
- Leaks in the vacuum or sensor hose leading to the turbo compressor inlet pressure sensor
- Internal leak inside the turbo compressor inlet pressure sensor itself
- A general problem within the wiring harness between the sensor and the ECM
- Incorrect sensor installed (wrong part fitted in place of the correct pressure sensor)
- A faulty or defective turbo compressor inlet pressure sensor
- A defective ECM
How to troubleshoot CAT Engine 27513: first checks
- Check for other active or logged diagnostic codes on the turbo compressor inlet pressure sensor or atmospheric pressure sensor before doing anything else. Calibration will not succeed while sensor diagnostic codes are active.
- Inspect the connectors and wiring at the sensor and along the harness back to the ECM for corrosion, looseness, chafing, or damage.
- Inspect the hose or vacuum line running to the turbo compressor inlet pressure sensor for cracks, splits, or leaks.
- Confirm the correct sensor part is installed in the right turbo compressor inlet location, not a mismatched or incorrect sensor.
- Using Cat ET, check the live reading of the turbo compressor inlet pressure sensor against the atmospheric pressure sensor reading with the engine off to see how far apart they are.
- Verify the sensor supply voltage and signal wiring at the ECM connector pins feeding the sensor circuit, since the sensor runs on a shared 5.0-volt analog supply and ground common to other analog sensors.
How the code clears
This is described as an active-only code that is not logged into ECM memory, so it should clear on its own once the underlying calibration succeeds. The recommended path is to run a manual Pressure Sensor Calibration through Cat Electronic Technician (Cat ET): connect to the data link connector, go to Service, then Calibrations, then Pressure Sensor Calibration. Entering that screen causes the ECM to attempt the calibration. Before running it, resolve any active or logged diagnostic codes on the pressure sensors involved, since a calibration will not succeed while those are present. After calibration, verify sensor readings fall within the allowed pressure differences from atmospheric pressure. If manual calibration still fails, work through the wiring, hose, sensor, and ECM causes listed above.
Affected models and serial ranges
27513 appears in our records across 1 CAT Engine models. Match your machine by model and serial number.
| Model | Serial ranges |
|---|---|
| C27 | Serial range not listed in source records |
Frequently asked questions
What does CAT code 27513 mean?
It means the ECM's automatic calibration of the right turbo compressor inlet pressure sensor against the atmospheric pressure sensor did not succeed. The sensor reading was outside the allowed range or did not match atmospheric pressure closely enough, so the ECM could not trust it.
Will code 27513 cause a loss of engine power?
Yes. When the turbo compressor inlet pressure sensor calibration fails or the sensor signal is otherwise flagged as invalid, the ECM cannot reliably judge air filter restriction, and it responds with a derate. Related conditions describe engine power derated up to 20 percent.
Is code 27513 stored in the ECM's memory?
No. It is described as an active code only. It will show on the diagnostic lamp or scan tool while the fault condition is present, but it is not logged into permanent memory.
How do I fix a failed turbo inlet pressure sensor calibration?
Check for and resolve any other active sensor diagnostic codes first, since those block calibration. Inspect wiring, connectors, and hoses for damage or leaks, confirm the correct sensor is installed, then run a manual pressure sensor calibration using Cat ET through Service, Calibrations, Pressure Sensor Calibration.
Can cranking the engine right after key-on cause this code?
Yes. The automatic calibration only runs if the engine is not cranked in the first few seconds after the ECM powers up. If it is cranked too soon, the ECM aborts the calibration attempt and uses the previous stored calibration value instead, or fails to calibrate a brand new control that has no previous value.
Does a bad hose or leak cause this code?
Yes. A leak in the vacuum or sensor hose to the turbo compressor inlet pressure sensor, or an internal leak inside the sensor itself, are both listed as possible causes of a failed calibration.
What is the difference between this code and a short-to-ground turbo inlet pressure fault?
A separate condition sets when the ECM reads the right turbo compressor inlet pressure signal below 0.2 VDC, indicating a short to ground. That condition is logged into memory, flags the pressure and filter restriction data as invalid, derates the engine 20 percent, and turns on the filter restriction lamp. Code 27513 itself is the calibration failure, which is active only and not logged.