What This Sensor Does and Where It Lives
This is a fuel rail pressure sensor - it threads into the high-pressure common rail on the ISX and tells the ECM what the actual pressure is versus what it's commanding. When these go bad or go flaky, you get rail pressure codes, hard starts, power loss, sometimes just a check engine light with no real drivability complaint yet.
4921499 is the Cummins number stamped on the OE unit. It's a three-wire sensor, screws into the rail with a specific thread and seal, and the connector has to match your harness pigtail exactly or you're modifying wiring you don't want to be modifying.
Before you order, pull the old sensor and read the number off it. ISX engines went through enough running changes over the years that 'it's an ISX' isn't specific enough - the number on the part is your surest confirmation, VIN is your backup.
Why These Cross Numbers Show Up Together
The cross-reference numbers we list - 3330998, 3408377, 050646, CUP050646 - all point back to the same sensor design and mounting configuration as 4921499. Cummins re-numbered this part more than once over its production run, and the Wabco/CUP numbers show up because the sensor itself was sourced from an outside supplier and relabeled.
Fortpro's F238829 and Tamerx's 4921499TX are aftermarket-built versions meant to bolt in and read the same way. Thread pitch, seal ring, and connector pinout are what actually matter here - a sensor that looks right but has a different pin order or seal size will either not seal against rail pressure or throw a false code.
If you're not sure which one you've got, don't guess off a parts catalog picture. Match the number stamped on your old sensor or give us your VIN and we'll confirm before it ships.
Ordering From PartStop
We're in Tacoma and keep this one in stock - if you're local and need the truck back on the road, same-day pickup or install is usually doable. If you're anywhere else, it ships nationwide and typically moves fast since it's a small, light part.
This is aftermarket, not a Cummins dealer part, and we price it that way - $49 versus what you'll pay at the dealer counter for the same fit. It carries our standard 6+ month warranty, so if it's DOA or fails early, we handle it.
Last thing: always confirm by the number on the sensor you're pulling off, not just by engine family. A five-minute check before ordering saves a return shipment later.
4921499 Cross-Reference & Interchange Numbers
These manufacturer and aftermarket numbers commonly cross-reference to 4921499. Use them to identify the part — then confirm the exact fit by VIN or the number stamped on your old unit before you order. An interchange is a starting point, not a fitment guarantee.
| Brand / Line | Cross-Reference Numbers |
|---|---|
| Cross-Reference | 3330998, 3408377, 050646, CUP050646 |
| Fortpro | F238829 |
| Tamerx | 4921499TX |
Frequently asked questions
Does 4921499 fit my Cummins ISX?
Likely, but confirm by the number stamped on your old sensor or your VIN first - ISX production ran long enough that Cummins used more than one rail pressure sensor part number across different builds.
Is the Fortpro F238829 the same as the Cummins 4921499?
It's built to cross-reference to it - same mounting thread, seal, and connector pinout as far as fit and function. It's an aftermarket part, not a Cummins-branded one, so confirm your old part's number matches this cross before ordering.
How do I know if this sensor is actually bad versus a wiring issue?
A fault code alone doesn't confirm the sensor - check the harness connector for corrosion and test resistance if you've got the specs handy. If the connector and wiring look clean and you're still getting rail pressure faults, the sensor's the likely culprit.
Not sure it fits? We check before you pay.
Run your VIN and we’ll match parts to your exact truck, or call the counter — a person who knows trucks verifies fitment by OEM number before the order ships. No wrong-box returns.
More cross-reference guides
Need the part, not just the reading?
Every part below is a Premium Quality aftermarket Direct Replacement with published OEM cross-reference numbers, a 6+ month warranty and same-business-day shipping from Tacoma, WA. Not sure it fits? Run your VIN — or call and a person who knows trucks will verify fitment before you pay.