Diagzone Xdiag Subscription Renew, LAUNCH LTR-01 RF Sensor, Thinkdiag Renew , Scania SDP3 Installation
This instruction show diagnostics steps for Caterpillar C9 engine coolant level signal invalid fault code 12 111-2.
Related Contents:
Caterpillar ET 2024A 2023A 2018A Diagnostic Software Free Download
CAT Communication Adapter 3 478-0235
Caterpillar Factory 18 Digits Password Service
Conditions Which Generate This Code:
This condition occurs when the coolant level sensor signals indicate a low condition and a normal condition at the same time. The “Coolant Level Sensor” parameter must be programmed to “4-pin”, “2-pin switch”, or “2-wire Float Sensor”before this diagnostic code can occur.
The coolant level sensor is installed by the vehicle’s Original Equipment Manufacturer (OEM). This sensor is an optional sensor for “Engine Monitoring”. Engine monitoring is a programmable feature of the Caterpillar Engine
Control Module (ECM).The sensor is selectable through a customer programmable parameter and the customer programmable parameter may be protected by customer passwords. Some OEM installed coolant level sensors are not connected to the ECM. Do not confuse an OEM installed coolant level sensor that is independent of engine monitoring with the coolant level sensor that is used for engine monitoring.
The customer programmable parameter for the coolant level sensor can be programmed to “4-Pin”, “2-wire float sensor”, or “2-pin switch”. Also, the customer programmable parameter for the coolant level sensor can be programmed to “NO” if the option for the coolant level sensor is not being used.
If the parameter “Coolant Level Sensor” is programmed to “NO”, the coolant level sensor is ignored by the ECM. Conversely, if the parameter is set, then a sensor must be installed. The coolant level is monitored by the engine monitoring system when the parameter “Coolant Level Sensor” is programmed to “4-Pin” or “2-wire float sensor”.
Probable Causes:
1) Coolant level sensor
2) Coolant level sensor harness/connector
3) ECM Connection
4) Wiring between ECM and coolant level sensor
5) ECM Failure
More repair case for Caterpillar machine,please refer to:Caterpillar Machine Repair
How useful was this post?
Click on a star to rate it!
Average rating / 5. Vote count:
Please keep this link if you copy the post!
Tags: Caterpillar
Related Posts

What is GODIAG GT106 Plus? How to Use?
2024.12.24

TOP 12 Best Diagnostic Tools for Trucks In 2025
2025.03.12

Caterpillar C9 Engine Injection Actuation Pressure Output Fault Solution
2025.07.9

PACCAR ESA Electronic Service Analyst v5.7 With Generation 5 Files & SW Flas...
2025.03.12

Inpower Pro V14.5 Cummlns Genset Diagnostic Tool Scanner for Cummins Generator S...
2025.03.12

Caterpillar C9 Engine 15 164-3 Injection Actuation Pressure Voltage High
2025.02.24

JLR SDD Software now updated to V165
2025.03.12

How to Solve Caterpillar C9 Engine Coolant Level Voltage High 12 111-3 Fault
2025.02.9

Caterpillar C9 Engine 01 71-0 Idle Stop Override Solution
2025.03.12

Nexiq ETechnician V2.12 Diagnostic Software 2024.09
2025.03.12