LEMON Manuals: Even more car manuals for everyone
Home >> Chevrolet >> 2020 >> Express 2500 LS, 6.0L Eng VIN G >> Repair and Diagnosis >> External Pages >> Different car >> Section 18 (Lighting System) >> Diagnostic Information and Procedures >> Headlamps Malfunction >> Diagnostic Fault Information

Diagnostic Fault Information

WARNING: This page is about a different car, the 2019 GMC Savana 3500, 2019 GMC Savana 2500, 2019 Chevrolet Express 3500, and 2019 Chevrolet Express 2500. However, it is still accessible from the selected car via links, so may be relevant.
Circuit Short to Ground Open/High Resistance Short to Voltage Signal Performance
Flash to Pass Switch Signal 4 4 4 -
Headlamp Dimmer Switch High Beam Signal 4 4 4 -
Headlamp Switch Headlamps Off Signal B257A 00 3 3* -
Headlamp Switch Headlamps On Signal B257A 00 3 3* -
Park Lamp Switch On Signal B257A 00 B257A 00 B257A 00* -
High Beam Headlamp Control 2 2 2 -
High Beam Relay Control 2 2 B2580 00 -
Low Beam Headlamp Control 1 1 1 -
Low Beam Relay Control 1 1 B2575 00 -
Low Beam Headlamp Ground - 1 - -
High Beam Headlamp Ground - 2 - -
Headlamp Switch Ground - 3 - -
Turn Signal/Multifunction Switch Ground - 4 - -
* Internal damage to the headlamp switch may occur if shorted to B+
1. Headlamp Malfunction - Low Beam
2. Headlamp Malfunction - High Beam
3. Headlamp Switch Malfunction
4. Dimmer Switch Malfunction