CAT Engine 1014 Fault Code: Crankcase Air Pressure Sensor : Voltage Below Normal
Also called Crankcase Air Pressure Sensor - Voltage Below Normal, Crankcase Air Pressure Sensor : Voltage Above Normal, Crankcase Air Pressure Sensor: Voltage Below Normal, Crankcase Air Pressure Sensor:Voltage Below Normal, Crankcase Pressure Short to Ground, Crankcase Pressure short to ground
Crankcase Air Pressure Sensor : Voltage Below Normal · ai-assisted, editor-reviewed · Last updated 2026-07-13
TL;DR
CAT code 1014 means the ECM saw crankcase air pressure sensor signal voltage below 0.2 VDC for one second after the ECM had been powered for three seconds, indicating a short to ground or a failed sensor circuit. Affects C13, C15, C175, C18, C27, and C32 engines. The ECM disables crankcase pressure monitoring until the fault is resolved.
Medium severity. This code disables the crankcase pressure monitoring function rather than shutting the engine down. It should be diagnosed promptly since it removes a monitoring safeguard, but it is not an immediate stop-engine event on its own.
What does CAT Engine error code 1014 mean?
Crankcase fault code 1014 is set when the ECM reads a crankcase air pressure sensor signal that has dropped below 0.2 VDC for at least one second, while the ECM has already been powered for three seconds. This voltage pattern looks like a signal wire shorted to ground rather than a real pressure reading.
When this happens, the ECM logs the CID-FMI in memory, viewable on a display module or diagnostic scan tool, flags the crankcase pressure reading as invalid data, and disables the engine's crankcase pressure monitoring system until the issue clears.
This code will not set if diagnostic codes 262-03 or 262-04 are already active, since those indicate a related sensor problem already being tracked.
What triggers a CAT Engine 1014 code?
The ECM sets this code when signal voltage is below 0.2 VDC for one second, with the ECM powered for at least three seconds, and codes 262-03 and 262-04 not currently active.
Common causes of 1014
- Damaged, corroded, or shorted connectors and wiring at the crankcase pressure sensor circuit
- Problem within the wiring harness itself, separate from the connectors
- Faulty or failed crankcase air pressure sensor
- Faulty ECM
- Vacuum leak affecting the crankcase pressure system
- Low oil level
- Low fuel level
- Intermittent connection or wiring problem that only shows up under vibration or temperature change
How to troubleshoot CAT Engine 1014: first checks
- Inspect the sensor connector and wiring harness for damage, corrosion, or pins pushed back out of the connector body
- Check the sensor circuit wiring: supply voltage is on terminal 1, sensor return on terminal 2, and sensor signal on terminal 3 of the pressure sensor connector
- Verify engine oil level and fuel level, since both are listed as possible causes of this code
- Look for a vacuum leak in the crankcase pressure system components and hoses
- Wiggle-test the harness and connector with the engine off to check for an intermittent short to ground
- If wiring and connectors check out, test or swap the crankcase air pressure sensor before suspecting the ECM
How the code clears
No separate clearing step is listed for this code beyond repairing the wiring, connector, sensor, or ECM fault that caused it. Once the underlying short to ground is corrected and the sensor signal returns to a normal range, the ECM should stop logging the active code. Running an ECM automatic calibration, which occurs when the ECM is powered and the engine is off for at least five seconds, can help confirm the sensor and circuit are reading correctly again.
Affected models and serial ranges
1014 appears in our records across 6 CAT Engine models. Match your machine by model and serial number.
| Model | Serial ranges |
|---|---|
| C13 | Serial range not listed in source records |
| C15 | Serial range not listed in source records |
| C175 | Serial range not listed in source records |
| C18 | Serial range not listed in source records |
| C27 | Serial range not listed in source records |
| C32 | Serial range not listed in source records |
Frequently asked questions
What does CAT code 1014 mean?
It means the ECM detected crankcase air pressure sensor signal voltage below 0.2 VDC for one second, which the ECM reads as a short to ground on that sensor circuit rather than a valid pressure reading.
Is CAT fault 1014 serious enough to stop working?
It is not listed as a shutdown code. The ECM disables crankcase pressure monitoring and logs the fault, but the engine keeps running. Even so, it should be diagnosed soon since it removes a monitoring function.
Which CAT engines can show code 1014?
This code applies to the C13, C15, C175, C18, C27, and C32 engine models.
Can low oil or fuel level cause this code?
Yes. Low oil level and low fuel level are both listed as possible causes alongside wiring, connector, sensor, and ECM problems.
What wiring should I check first for code 1014?
Check the sensor connector terminals: terminal 1 carries supply voltage, terminal 2 is sensor return, and terminal 3 carries the sensor signal for the pressure sensor. Look for damage, corrosion, or a short to ground on terminal 3.
Will a vacuum leak trigger this code?
Yes, a vacuum leak affecting the crankcase pressure system is listed as one of the possible causes.
Does code 1014 mean the ECM is bad?
Not necessarily. A faulty ECM is listed as a possible cause, but it is usually the last thing to check after ruling out connectors, wiring, and the sensor itself.