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Electronic Control System Gas Plus Engines – FAULT CODE 233

Engine Coolant Pressure Low Warning

Overview

CODE REASON EFFECT
Fault Code: 233
PID: P109
SPN: 109
FMI: 1
LAMP: Amber
SRT: 

Engine Coolant Pressure Low – Warning

Progressive power derate increasing in severity from time of alert. If engine protection shutdown feature is enabled, engine will shut down 30 seconds after red stop lamp starts flashing.

Coolant Pressure Sensor Circuit
SMALL | MEDIUM | LARGE

Circuit Description

The coolant pressure sensor is used by the electronic control module (ECM) to monitor the coolant pressure. The ECM monitors the voltage on the signal pin and converts this to a pressure value. The coolant pressure value is used by the ECM for engine protection.

Component Location

The coolant pressure sensor is located on the engine block, below the water outlet location.

Shop Talk

The engine protection shutdown for coolant is a customer feature and will only be enabled at the customer’s request. This feature will deactivate or disable the fuel control valve if this feature is utilized by the OEM.

Troubleshooting Steps

STEPS SPECIFICATIONS
STEP 1. Check the engine coolant pressure sensor accuracy.  
  STEP 1A. Check the sensor accuracy. Sensor reading within 34.5 kPa [5 psia]?
STEP 2. Check engine coolant pressure.  
  STEP 2A. Check engine coolant pressure with a mechanical gauge. Is coolant pressure greater than the specified value?
STEP 3. Clear the fault codes.  
  STEP 3A. Disable the fault code. Fault Code 233 inactive?
  STEP 3B. Clear the inactive fault codes. All fault codes cleared?

Guided Step 1 – Check the engine coolant pressure sensor accuracy.

Guided Step 1A – Check the sensor accuracy.

Conditions

  • Connect a mechanical pressure gauge
  • Connect INSITE™ electronic service tool to the vehicle datalink.

Action

  • Start the engine and compare the coolant pressure reading on the service tool monitor screen in INSITE™ electronic service tool to the reading on the mechanical coolant pressure gauge. Note: Pressure sensor displays in absolute, add atmosphere pressure to gauge reading.

Sensor reading is correct?
YES NO
No Repair

Replace the sensor if INSITE™ electronic service tool reading differs from mechanical gauge reading. Refer to Procedure 019-157.

Guided Step 2 – Check engine coolant pressure.

Guided Step 2A – Check engine coolant pressure with a mechanical gauge.

Conditions

  • Remove the coolant pressure/temperature sensor
  • Turn keyswitch ON
  • Connect a mechanical pressure gauge
  • Start engine and warm engine to above 82°C [180°F].

Action

Minimum coolant pressure specification with thermostat open:

  • Idle: 13.7 kPa [2 psi]
  • 2300 rpm: 172 kPa [25 psi]

Is coolant pressure greater than the specified value?
YES NO
No Repair No Repair

Refer to the Coolant Pressure Low troubleshooting symptom tree in the Troubleshooting and Repair Manual C8.3G, C Gas Plus, and L Gas Plus Engines, Bulletin 3666206.

Guided Step 3 – Clear the fault codes.

Guided Step 3A – Disable the fault code.

Conditions

  • Connect all components
  • Turn keyswitch ON
  • Connect INSITE™ electronic service tool.

Action

  • Start the engine and let it idle for one minute.
  • Use INSITE™ electronic service tool to verify that the fault code 233 is inactive.

Fault Code 233 inactive?
YES NO
No Repair

Repeat the troubleshooting steps. If fault code remains active, refer to the Coolant Pressure Low troubleshooting symptom tree in the Troubleshooting and Repair Manual C8.3G, C Gas Plus, and L Gas Plus Engines, Bulletin 3666206.

Guided Step 3B – Clear the inactive fault codes.

Conditions

  • Connect all components
  • Turn keyswitch ON or Run/Stop switch to the RUN position
  • Connect INSITE™ electronic service tool.

Action

  • Use INSITE™ electronic service tool to erase the inactive fault codes.

All fault codes cleared?
YES NO
No Repair

Troubleshoot any remaining active fault codes.
Repair complete
Appropriate troubleshooting charts
Last Modified:  28-Sep-2004
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Published by Jack

Hello, I'm Jack, a diesel engine fan and a blogger. I write about how to fix and improve diesel engines, from cars to trucks to generators. I also review the newest models and innovations in the diesel market. If you are interested in learning more about diesel engines, check out my blog and leave your feedback.