# Service bulletin SB25\-L\-001A

A bulletin is a manufacturer's communication to its dealers, as NHTSA indexes it. The summary is NHTSA's. The document is the manufacturer's: read it at NHTSA. A bulletin is not a recall, and listing a model year does not mean every vehicle of it is concerned.

- Type: Service bulletin
- NHTSA id: 11026137
- Published by NHTSA: 2025\-12\-04
- Manufacturer's number: SB25\-L\-001A
- Manufacturer's date: 2025\-11\-21
- NHTSA component: ENGINE
- Manufacturer's system: FUEL \& EXHAUST

## NHTSA's summary

SERVICE BULLETIN: THE ORIGINAL CALIBRATIONS IN THE ENGINE CONTROL MODULE \(ECM\) AND THE DIESEL EXHAUST FLUID CONTROL UNIT \(DCU\) OF CERTAIN 2025MY N\-DIESEL VEHICLES CONTAINED INCORRECT LOGIC THAT MAY UNNECESSARILY CAUSE DIAGNOSTIC TROUBLE CODE \(DTC\) P2201 NOX SENSOR CIRCUIT PERFORMANCE SENSOR 1 TO SET AND ILLUMINATE THE MALFUNCTION INDICATOR LIGHT. THIS DTC MAY BE RESOLVED BY REPROGRAMMING BOTH ECM AND DCU WITH THE REVISED SERVICE CALIBRATIONS. FOLLOW THE DIAGNOSTIC FOR THIS DTC. IF NO MECHANICAL FAULT CAN BE FOUND DURING NORMAL DIAGNOSIS, FOLLOW THE SERVICE PROCEDURE IN THIS BULLETIN TO CORRECT THE CONCERN.

## The document

- [NHTSA's copy of the document (PDF)](https://static.nhtsa.gov/odi/tsbs/2025/MC-11026137-0001.pdf)
- [If that address does not open, try this one](https://static.nhtsa.gov/odi/tsbs/2025/MC-11026137-9999.pdf)

The document is the manufacturer's. This site does not hold it.

## Components

Engine

## Trouble codes named

P2201

## Vehicles listed

- 2025 ISUZU N\-SERIES

JSON: [/v1/bulletins/11026137](/v1/bulletins/11026137)

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