The dreaded “Warn Engine” light on your International truck’s dashboard can be a source of frustration and anxiety. This article details a real-world experience with this issue, focusing on a faulty DPF pressure sensor circuit and a surprisingly simple solution. Understanding this problem can save you time and money on unnecessary repairs.
Decoding the DPF Pressure Sensor Issue
The journey began with a persistent amber “Warn Engine” light. Diagnostic codes pointed to a problem with the Diesel Particulate Filter (DPF) pressure sensor, preventing the DPF from regenerating. Replacing both pressure sensors didn’t resolve the issue. Further investigation revealed a short circuit in the wiring harness, where a single circuit received input from seven different sources.
A Temporary Reprieve and a Relapse
Surprisingly, the code cleared itself overnight. Extensive testing failed to reproduce the error, leading to the assumption of a delayed computer response. However, a celebratory truck wash trip reactivated the warning light, sending the truck back to the shop. Suspecting water intrusion, the focus shifted to the wiring harness connectors, known weak points in electrical systems.
The Culprit: A Leaky Connection
The problem was traced to a two-piece DPF sensor wiring harness with a connection located under the cab, near the frame rail on the driver’s side. This connection, despite having weather protection, had accumulated water. Draining the water, cleaning the connection with an electrical contact cleaner, and sealing it with silicone resolved the issue.
A Potential Widespread Issue
International has been notified of this problem and is investigating a permanent fix. This suggests a potential service advisory might be issued in the future. If you experience intermittent “Warn Engine” lights on your International truck, recommend your mechanic inspect the DPF sensor wiring harness connection for water damage. This simple check could save you from extensive and costly repairs. A seemingly minor leak can lead to significant downtime and frustration, highlighting the importance of thorough diagnostics and attention to detail.
