P24E5 code meaning
NH3 Sensor Circuit Intermittent/Erratic
Powertrain system Generic code P24xx codes Check engine light
What P24E5 means
P24E5 covers an NH3 sensor signal that jumps or drops out for short moments while staying mostly in range. Vibration, heat cycling of the exhaust and road salt make loose connector pins and cracked insulation near the SCR can the main suspects. Ram fitted such a sensor to the 2014 3500 to 5500 cab chassis with the 6.7 L Cummins; bulletin 18-042-20 offers one engine calibration for trucks that keep it and another for trucks where it was removed, and warns that implausible-data or lost-communication codes appear when the wrong one is loaded. No manufacturer documents P24E5 publicly. CARB asks for erratic-signal detection on heavy-duty emission sensors. Steady faults are P24E3 and P24E4.
P24E5 at a glance
- Check engine lightYes, usually on
- Emissions testCan fail
- Limp modeNot expected
- Repair difficultyMedium
- Typical labor0.5 to 3 hours
- Clears after repairAfter a drive cycle
Symptoms of P24E5
- Warning lamp that comes and goes
- Live data shows spikes in the ammonia value
Common causes of P24E5
- Most likelyLoose or corroded pins at the sensor or module connector
- PossibleHarness insulation cracked by exhaust heat and vibration
- Less likelySporadic internal fault in the sensor electronics
Check the most likely causes first. Replacing parts by guesswork is the most expensive way to clear a code.
Parts involved
Nh3 sensorSensor wiringSensor connector
What each part of P24E5 means
| P | Powertrain system: engine, fuel system, ignition, emissions and transmission. |
| 2 | Generic code (second SAE range): it means the same on every make. |
| 4 | Area: auxiliary emission controls (catalytic converter, EGR, EVAP). |
| E5 | The exact fault in that area. |
What to do next
- Note P24E5 and any other codes stored with it: several codes together often point to one cause.
- Check for loose connectors and damaged wiring around the parts the code names.
- Check open recalls for your car: some faults are fixed for free by the dealer. Enter your VIN.
- Clear the code only after the repair. If it comes back, the fault is still there.
Buying a used car? Scan it for stored codes before you pay. A recently cleared memory can hide a problem.
Questions about P24E5
What does P24E5 mean?
P24E5 means "NH3 Sensor Circuit Intermittent/Erratic". P24E5 covers an NH3 sensor signal that jumps or drops out for short moments while staying mostly in range. It is a generic code, so it means the same on every make.
Is it safe to drive with P24E5?
Usually yes, for a short time, if the check engine light is steady and the car drives normally. If the light flashes or the car runs badly, stop and have it checked.
Will P24E5 fail an emissions test?
Yes, it can. P24E5 is emissions-related, so most inspection programs fail a car while it is stored or while the check engine light is on.
How hard is P24E5 to fix?
Difficulty: medium. A typical repair takes 0.5 to 3 hours of work. This is a job for a workshop.
Will P24E5 clear itself after the repair?
After the repair the car has to complete a drive cycle (a mix of city and highway driving) before the test runs again. Until then the readiness monitor shows "not ready", which can fail an inspection.