Cummins fault code · Auxiliary inputs, outputs and generator controls

Cummins fault code 296

Auxiliary Pressure Sensor Input 2: special instructions

J1939 SPN1388
FMI14
LampRed stop lamp
SystemAuxiliary inputs, outputs and generator controls

What it means

Cummins' description: Auxiliary Pressure Sensor Input 2 - Special Instructions.

SPN 1388 is Auxiliary Pressure #2. FMI 14 means the fault requires specific troubleshooting steps from Cummins service information.

These codes cover extra inputs and outputs the ECM controls or monitors: auxiliary temperature and pressure sensors, relays, lamps, and generator or equipment controls on off-highway and generator engines.

What the lamp means

A red stop lamp means Cummins treats this as serious. Stop the engine as soon as you can do it safely and get it checked before running it again.

How serious is it?

Green, yellow, red: three ways this can look

The same code can be a quick fix or a reason to shut down. Match your situation to the closest example. Cummins rates this a red stop lamp code, so if the red lamp is on, go by the red example.

Green

Keep an eye on it

An auxiliary code for an accessory that isn't used on your truck.

Yellow

Schedule a repair

An accessory, gauge or lamp not working with the code set. Fix the circuit when convenient.

Red

Stop and get help

The code is tied to a shutdown or protection relay. Have it checked before relying on that protection.

Common causes

The sensor reading itself is out of range or the condition is real, so look at the system:

  • Real reading from the equipment the input is monitoring

What you can check before calling

  • Find out what the auxiliary input is wired to on your truck or equipment
  • Check connectors and relays in that circuit

Clearing the code without fixing the cause usually brings it right back, and on emissions systems it can restart derate timers.

Engines and sources

Listed by Cummins for: QSB 6.7, QSL 9, QSX 15, QSB 4.5, QSF 3.8, QSG 12. Cummins uses the same fault code numbers across its electronic engines, including on-highway models like the ISB/B6.7, ISL/L9 and ISX/X15, though not every code applies to every engine or software level. Source: Cummins Tier 4 Fault Codes. Always confirm with Cummins service information (QuickServe) for your engine serial number.

  • Older Cummins engines may report this code as SPN 1387 FMI 14 (Auxiliary Pressure Sensor Input # 2 Engine Protection - Critical).
  • Older Cummins engines may report this code as SPN 1084 FMI 14 (Auxiliary Pressure Sensor Input # 2 Engine Protection - Critical).

Look up another code

Cummins fault code (like 1922), J1939 SPN and FMI (like SPN 3251 FMI 0), or an OBD-II code (like P0420).

Questions

What does Cummins fault code 296 mean?

Cummins fault code 296 is J1939 SPN 1388 FMI 14: Auxiliary Pressure Sensor Input 2 - Special Instructions. In plain terms: auxiliary pressure sensor input 2: special instructions.

Can I keep driving with Cummins code 296?

No. Cummins assigns this code a red stop lamp. Stop the engine as soon as it's safe and have it checked before running it again. Look at the green, yellow and red examples on this page to judge your situation.

What is the SPN and FMI for Cummins code 296?

SPN 1388 identifies the part or system (Auxiliary Pressure #2). FMI 14 describes the type of failure: special instructions.

What usually causes Cummins code 296?

The most common causes are: real reading from the equipment the input is monitoring.

Diesel down in the Midlands?

We work on Cummins-powered pickups, vans and medium-duty trucks across Lexington, Columbia and the Midlands, on site at your yard or roadside.

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