CAT Engine 2624 Fault Code: 5 Volt Sensor DC Power Supply short to ground
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5 Volt Sensor DC Power Supply short to ground · ai-assisted, editor-reviewed · Last updated 2026-07-13
TL;DR
CAT code 2624, SPN 3509 FMI 4, means the ECM has detected that the 5 volt sensor supply voltage has dropped below normal, typically pointing to a short to ground or a wiring/connector problem feeding the analog sensor circuits. The ECM logs the code and sets all affected analog sensors to default values, which can cause derates or rough engine behavior until it is fixed.
High severity. The engine can keep running on default sensor values, but multiple pressure and temperature readings become unreliable at once. This can mask real problems (low oil pressure, high crankcase pressure, etc.) and risks sensor damage if the fault is a short to a higher voltage source. Diagnose before extended operation.
What does CAT Engine error code 2624 mean?
Code 2624 covers the 5 volt DC sensor power supply that the ECM sends out to power a whole group of analog sensors at once, including atmospheric pressure, engine oil pressure, fuel pressure, intake manifold pressure, crankcase pressure, turbocharger inlet pressure, coolant temperature, fuel temperature, and others depending on engine model. A related 8.0 ± 0.4 VDC supply feeds the throttle position sensor on some models.
This code sets when the ECM sees that regulated supply voltage drop below normal, generally caused by a short to ground somewhere in the supply wiring or inside a sensor itself. Because one supply circuit feeds many sensors, a single wiring fault can knock out readings across several systems simultaneously.
When the code is active, the ECM logs it and sets all affected analog sensors to their default values. This means the engine is running on assumed, not measured, values for several parameters, which is why the code is treated seriously even though the engine may keep running.
What triggers a CAT Engine 2624 code?
Documented set conditions vary slightly by engine family. In general the ECM reads the analog sensor supply voltage below 4.8 volts for two seconds (with the ECM powered for at least two seconds, or in some descriptions at least three seconds) and logs the code. One version states the supply voltage below normal for one second triggers logging. Normal supply voltage is 5.0 ± 0.2 volts DC; the throttle position sensor supply runs at 8.0 ± 0.4 volts DC. Related -10 style logic (steady/unchanging sensor signal for more than 30 seconds) and -21 style logic (5 volt supply missing entirely at the sensor) are described for companion codes in the same 5 volt supply family, not exclusively 2624.
Common causes of 2624
- Damaged, corroded, or loose connectors and wiring on the 5 volt supply or sensor return circuits
- An internal electrical problem with one of the sensors fed by the shared 5 volt supply
- The supply wire shorted to another wire in the harness or shorted to engine ground
- The supply wire shorted to a higher voltage source, which can overvoltage and damage unprotected sensors
- An open circuit in the analog sensor common/return wire
- Intermittent wiring problems that only show up under vibration or temperature changes
- A faulty ECM (listed as a possible cause across multiple versions of this code)
How to troubleshoot CAT Engine 2624: first checks
- Check the diagnostic lamp or scan tool to confirm 2624 is active versus historical, and look for any other active analog sensor fault codes at the same time, since a supply fault can affect many sensors at once
- Inspect the wiring harness and connector pins feeding the 5 volt analog sensor supply for corrosion, pinched wires, chafing, or contact with ground or battery voltage
- With the key off, check the supply wire for a short to ground or a short to a higher voltage source, and check the return/common wire for an open circuit using appropriate meter checks
- Disconnect sensors one at a time (if practical) to isolate whether a single sensor is dragging the shared supply down, since an internal sensor short can pull the whole circuit low
- Verify supply voltage at the ECM connector itself; if it reads within the 5.0 ± 0.2 volt or 8.0 ± 0.4 volt spec at the ECM but not at the sensor, the fault is in the harness, not the ECM
- If a short to battery voltage is suspected, check any sensors that were on that circuit for damage before returning the system to service, since sensors are not protected from overvoltage
How the code clears
No separate clearing step is listed beyond repairing the underlying wiring, connector, or sensor fault. Once the short or open is corrected and supply voltage returns to normal, the ECM should stop logging the code on its own; confirm with a scan tool that the code goes inactive and that dependent sensor readings return to live values instead of defaults.
Affected models and serial ranges
2624 appears in our records across 10 CAT Engine models. Match your machine by model and serial number.
| Model | Serial ranges |
|---|---|
| C10 | Serial range not listed in source records |
| C11 | Serial range not listed in source records |
| C12 | Serial range not listed in source records |
| C13 | Serial range not listed in source records |
| C15 | Serial range not listed in source records |
| C16 | 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 2624 mean?
It means the ECM's regulated 5 volt sensor power supply voltage has dropped below normal, most often from a short to ground or a wiring fault, causing the ECM to set affected analog sensors to default values.
Can I keep driving or running the equipment with code 2624 active?
The engine can usually keep running because the ECM substitutes default sensor values, but several real-time readings like oil pressure and manifold pressure are no longer trustworthy. Given the risk of sensor damage from a possible overvoltage short, it should be diagnosed as soon as possible rather than run indefinitely.
Which sensors are affected by the 5 volt supply fault?
Depending on the engine model, the shared supply can feed the atmospheric pressure sensor, engine oil pressure sensor, fuel pressure sensor, intake manifold pressure sensor, crankcase pressure sensor, turbocharger inlet pressure sensor, coolant temperature sensor, fuel temperature sensor, aftertreatment ID module, and exhaust temperature sensor buffers, among others.
Could this code mean a sensor is damaged, not just a wiring problem?
Yes. If the supply line shorted to battery voltage, sensors on that circuit are not protected from overvoltage and can be damaged. Check for active sensor-specific fault codes after repairing the supply circuit to see if any sensor also needs replacement.
Is this a wiring problem or an ECM problem?
Both are listed as possible causes. Damaged connectors, chafed wiring, and shorts to ground or higher voltage are the most common causes, but a faulty ECM is also listed as a possible cause if wiring and sensors check out normal.
What is the difference between the -10 and -21 style codes mentioned alongside 2624?
Those describe related fault behavior in the same 5 volt supply family: one version activates when a sensor signal stays abnormally steady for more than 30 seconds, and another activates when the 5 volt supply is missing entirely at the sensor. They are documented as companion logic to the supply-low condition that defines 2624.
Will fixing the wiring clear the code automatically?
No separate reset procedure is listed. Once the underlying short or open circuit is repaired and supply voltage reads normal again, the code should stop being active and can be confirmed cleared with a scan tool.