3238 Fmi 2 (2024)

FAQs

What is code spn 3238 fmi 2? ›

SPN 3238 fmi 2. This falls code leans towards commonly a faulty SCR outlet NOx sensor. Thoroughly inspect the wiring and if the wiring checks out OK, replace the sensor.

So here is the list of possible FMI values: 0 = Data Valid but Above Normal Operational Range, Most Severe Level. 1 = Data Valid but Below Normal Operational Range, Most Severe Level. 2 = Data Erratic, Intermittent or Incorrect (rationality) 3 = Voltage Above Normal, or Shorted to High Source.

This fault indicates that the real-time clock in the ECM lost power. Possible causes for this fault are weak or damaged real-time clock battery, damaged wiring or connectors between the battery and ECM, Or the vehicle battery power to the ECM is lost.

SPN is short for suspect parameter number. It identifies which electrical circuit, part or component of your truck isn't working properly. FMI stands for failure mode identifier—this part of the fault code tells you what type of problem your truck has.

Page 1. Failure Mode Identifier (FMI) Codes on J1939 data link. The FMI is used along with the SPN to provide specific information that relates to a diagnostic trouble code (DTC). The FMI may indicate that a problem with an electronic circuit or an electronic component has been detected.

shorted to high means voltage is reading higher than normal which could be caused by a faulty sensor or a short in the harness from another power source.

Financial market infrastructures (FMI) refer to all parts of the financial system that facilitate financial market transactions, including settlement.

Your iPhone, iPad, or iPod Touch includes a built-in security feature called Find My iPhone that is designed to prevent anyone else from using your iPhone, iPad, or iPod touch if it's ever lost or stolen. Activation Lock is enabled automatically when you turn on Find My iPhone on a device using iOS 7 or later.

It's important to repair or replace a faulty NOx sensor quickly to protect your engine and aftertreatment system. You can drive for a short time with a faulty one, with the engine running rich and over-using DEF, but the ECU will eventually send your truck into limp mode and engine derate.

It's important to disconnect both the positive and negative terminals and wait for about 15 minutes before reattaching them. This should reset the ECU and, in turn, the NOx sensor. After reconnecting the battery, take the vehicle for a test drive. This will allow the ECU to relearn and adapt to the new sensor status.

What can cause a NOx sensor to fail? ›

A major cause of NOx Sensor failure is soot from the combustion process. This can coat the sensor and affect the reading as the sensor can no longer measure the gas effectively. The soot is also abrasive; when larger particles of soot are present in the exhaust gas, the passing stream can damage the sensor.

Failure Mode Indication (FMI), as part of the J1939 standard used in heavy-duty vehicles, functions by closely monitoring system components. When a fault occurs, FMI generates a precise code that identifies the specific nature of the issue, much like an advanced version of a 'check engine' light.

Detection. TECU monitors the voltage from the analog Shift Control Device. Fault Code 14 sets when the reported voltage for a selected mode does not match the actual value for that lever position.

The FMI 5 in this example tells us that there is low current (amps) or an open in the circuit. Generally, this type of fault tells us that there is a wire that is broken or disconnected.

FMI 2 stands for Data Erratic, Intermittent, or Incorrect. This means that there is an issue with the Inlet Nozzle Pressure sensor that is causing the data to be erratic, intermittent, or incorrect. This code is for a loss of the high side pressure sensor signal.

SPN stands for Suspect Parameter Number. It's a diagnostic trouble code that provides detailed information about specific faults detected by the vehicle's ECU, making it easier to identify and address issues within the vehicle's electronic systems.

This code indicates an issue with the SCR outlet NOx sensor reading incorrectly. This may be an error with the sensor or an issue with the wiring or the exhaust. The sensor is located at the aftertreatment outlet right before the tail pipe.