What is the issue with abnormal post-processing wiring harness?
3 Answers
Post-processing wiring harness abnormalities can be caused by the following reasons: 1. Equipment failure: Faulty electrical equipment can easily damage the wiring harness, with common issues including short circuits and open circuits. Prolonged use of the wiring harness can lead to aging wires, damaged insulation, and inadequate mechanical strength, resulting in short circuits, open circuits, and grounding, which can burn out the harness. 2. Human error: During the assembly or repair of automotive components, metal objects may crush the wiring harness, causing the insulation to rupture; improper positioning of the wiring harness; incorrect connection of electrical device leads; or reversed connection of the battery's positive and negative leads.
As someone who frequently works on car repairs, I've encountered issues with the aftertreatment wiring harness several times. Usually, it's because the harness is exposed under the vehicle chassis and can easily get scratched by road debris or corroded, leading to short circuits or open circuits. For example, in my diesel vehicle, the wiring harness connecting the urea pump and sensors in the exhaust system's aftertreatment section—once there's an issue, the emission warning light on the dashboard comes on, and the engine tends to enter a torque limitation mode, making it sluggish. I recommend stopping immediately to inspect the wiring harness for any physical damage or loose connectors. Regular maintenance, like cleaning the chassis and replacing aging harness sheaths, can prevent such failures. After all, repairs are time-consuming and costly, and they might even affect the vehicle's compliance with emission standards.
During the last inspection of the aftertreatment harness, I found it primarily handles the urea injection and sensor signal circuits. Abnormalities often stem from internal wire core aging or external moisture corrosion. This can cause the system to misjudge error codes and trigger fault warnings. During repairs, use a diagnostic tool to read specific fault codes, check harness connectors and grounding, and replace the entire harness section if necessary. Don't forget these circuits are crucial for emission control—delayed repairs can increase fuel consumption and exhaust pollution. For DIY repairs, first disconnect the battery terminals to ensure safety, but it's best to have it handled at a professional shop to avoid messing up the circuits.
