Cummins fault code · Engine cooling

Cummins fault code 232

Coolant Pressure Sensor Circuit: circuit voltage low / shorted low

J1939 SPN109
FMI4
LampAmber warning lamp
SystemEngine cooling

What it means

Cummins' description: Coolant Pressure Sensor Circuit - Voltage below normal, or shorted to low source.

SPN 109 is Engine Coolant Pressure. FMI 4 means the voltage on the circuit is lower than possible for a good sensor, usually a short to ground, a damaged harness, or a failed sensor.

The cooling system keeps the engine at operating temperature. The ECM watches coolant temperature, pressure and level, and will derate or shut down the engine to protect it from overheating.

What the lamp means

An amber (yellow) warning lamp means the engine can usually keep running, but the fault should be repaired soon, ideally the same day.

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.

Green

Keep an eye on it

A coolant level warning that clears after topping off with the right coolant, and no leak shows up.

Yellow

Schedule a repair

Coolant keeps dropping, the gauge runs hotter than normal, or the amber lamp is on. Find the leak before it becomes an overheat.

Red

Stop and get help

Temperature gauge in the red, steam, a stop lamp, or engine protection derating power. Pull over and shut it down. Running hot can warp the head and ruin the engine.

Common causes

FMI 4 is an electrical or signal fault, so start with the circuit:

  • Coolant temperature or level sensor failed
  • Corroded connector
  • Harness chafed against the engine or radiator

If the circuit checks out, the reading may be real. Other possibilities: low coolant from a leak; radiator or charge air cooler blocked with dirt or bugs; fan clutch or fan not engaging.

What you can check before calling

  • Check the coolant level only with the engine cool
  • Look for leaks, wet spots or dried coolant residue
  • Clean the front of the radiator and charge air cooler
  • Watch the temperature gauge and whether the fan kicks on

Clearing the code without fixing the cause usually brings it right back, and on emissions systems it can restart derate timers. For the bigger picture, read our guide: Car overheating: what to do right now, and what's causing it.

Engines and sources

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.

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 232 mean?

Cummins fault code 232 is J1939 SPN 109 FMI 4: Coolant Pressure Sensor Circuit - Voltage below normal, or shorted to low source. In plain terms: coolant pressure sensor circuit: circuit voltage low / shorted low.

Can I keep driving with Cummins code 232?

Usually for a short time, if the engine runs normally and no other warnings are on. Get it diagnosed soon, because many amber codes lead to a derate if ignored. Look at the green, yellow and red examples on this page to judge your situation.

What is the SPN and FMI for Cummins code 232?

SPN 109 identifies the part or system (Engine Coolant Pressure). FMI 4 describes the type of failure: circuit voltage low / shorted low.

What usually causes Cummins code 232?

The most common causes are: coolant temperature or level sensor failed; corroded connector; harness chafed against the engine or radiator.

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