How to Clear Fault Code CA428 on Komatsu PC200-8

By SINOCMP Parts · January 24, 2024

1. Failure Description

User Code	E15	Failure	Water-in-fuel Sensor High Voltage Error (Engine Controller System)
Fault Code	CA428
Failure Details	There is a high voltage detected in the signal circuit of the water-in-fuel sensor
Controller Response	No particular response
Problem on Machine	The oil-water separator monitor displays an anomaly
Relevant Information	Signal (ON/OFF) from the water-in-fuel sensor can be detected with the monitoring function (Code: 18800); Method of reproducing failure code: Turn starting switch to the ON position.
Also Applicable to	PC200-8, PC220-8, PC210-8, PC300-8, PC400-8, etc.

2. Troubleshooting

Before getting down to specific troubleshooting, let's take a look at the circuit diagram below first:

Circuit Diagram for Fault Code CA428

The following are possible causes and detection methods:

Water-in-fuel Sensor Failure

Detection method: Turn the starting switch to the OFF position, be prepared, and then perform the fault diagnosis without turning the starting switch to the ON position.
Standard values: P47 between (1) and (2), maximum electrical resistance 10Ω, as shown in the diagram below.

Wiring Harness Open Circuit or Poor Connector Contact

Detection method: Turn the starting switch to the OFF position, be prepared, and then perform the fault diagnosis without turning the starting switch to the ON position.
Standard values: CE01 (concave) (14) - P47 (convex) (1) wiring harness, maximum electrical resistance 10Ω; CE01 (concave) (47) - JC02 - P47 (convex) (2) wiring harness, maximum electrical resistance 10Ω, as shown in the diagram below.

Wiring Harness Short Circuit (with Another Wiring Harness)

Detection method: Turn the starting switch to the OFF position, be prepared, and then perform the fault diagnosis without turning the starting switch to the ON position.
Standard values: CE01 (concave) (14) - CE01 (concave) pin-to-pin wiring harness (with all wiring harness connectors disconnected), minimum electrical resistance 100KΩ, as shown in the diagram below.

Faulty Wiring Harness Connector

Detection method: Check the connector parts among the water-in-fuel sensor, the engine wiring harness, and the engine controller. They may malfunction due to the following:
Loose connector, damaged lock, or damaged seal;
Pins that are rust, bent, damaged, pushed in, or expanded;
Moisture or oil sludge in the connector, or insulation failure.

Faulty Engine Controller

Detection method: Turn the starting switch to the OFF position, be prepared, and then perform the fault diagnosis without turning the starting switch to the ON position.
Standard values: CE01 (concave) between (14) and (47), maximum electrical resistance 10Ω, as shown in the diagram below.

3. Possible Solutions

If the problem is with the oil-water separator, you’re recommended to replace the Komatsu oil-water separator sensor 600-311-3720, 600-311-3721, 600-311-3722;

If the problem is with the engine controller, you’re recommended to replace the 600-467-1100 ECM controller. If you want to buy it here, please provide us with the VIN and pictures of the old controller, so that we can process your item quickly and accurately;

If the problem is with the wiring harness, please confirm its part number first and search for the product best suits your need.

4. More Technical Support

If you need more information or further assistance, please feel free to let us know via live chat or email: service@sinocmp.com, we will reach out to you ASAP.