SYS.OK|MANUAL.DB● LIVE
HOMESERVICE MANUALSCHEVROLET2019EXPRESS 2500 BASE, VAN CARGO EXTENDED, 6.0L ENG VIN GREPAIR AND DIAGNOSISEXTERNAL PAGESDIFFERENT CARSECTION 5 (12 V STARTING AND CHARGING SYSTEM)DIAGNOSTIC INFORMATION AND PROCEDURESDTC P0622CIRCUIT/SYSTEM TESTING
2019 Chevrolet Express 2500 Base, Van Cargo Extended, 6.0L Eng VIN G

Circuit/System Testing

2019 Chevrolet Express 2500 Base, Van Cargo Extended, 6.0L Eng VIN GSECTION Circuit/System Testing
WARNING: This page is about a different car, the 2018 GMC Savana 3500, 2018 GMC Savana 2500, 2018 Chevrolet Express 3500, and 2018 Chevrolet Express 2500. However, it is still accessible from the selected car via links, so may be relevant.
  1. Verify a test lamp illuminates between the G13 Generator B+ circuit terminal 1 X2 and ground.
    • If the test lamp does not illuminate and the circuit fuse is good 
    1. Remove the test lamp and disconnect the B+ cable at the G13 Generator.
    2. Test for less than 2 Ω in the B+ circuit end to end.
      • If 2 Ω or greater, repair the open/high resistance in the circuit.
      • If less than 2 Ω, verify the fuse is not open and there is voltage at the fuse.
    • If the test lamp does not illuminate and the circuit fuse is open 
    1. Remove the test lamp, disconnect the battery negative cable, and disconnect the G13 Generator B+ cable.
    2. Test for infinite resistance between the B+ circuit and ground.
      • If less than infinite resistance, repair the short to ground on the circuit.
    • Go to next step: If the test lamp illuminates 
  2. Disconnect the X1 harness connector at the G13 Generator, engine running.
  3. Verify the scan tool Engine Control Module Generator F - Terminal Signal parameter is less than 5%.
    • If 5% or greater 
    1. Ignition OFF, disconnect the harness connector at the K20 Engine Control Module, ignition ON.
    2. Test for less than 1 V between the signal circuit terminal 2 or C and ground.
      • If 1 V or greater, repair the short to voltage on the circuit.
      • If less than 1 V, replace the K20 Engine Control Module.
    • Go to next step: If less than 5% 
  4. Install a 3 A fused jumper wire between the signal circuit terminal 2 or C and B+.
  5. Engine running, verify the scan tool Engine Control Module Generator F - Terminal Signal parameter is greater than 95%.
    • If 95% or less 
    1. Ignition OFF, remove the jumper wire, disconnect the harness connector at the K20 Engine Control Module.
    2. Test for less than 2 Ω in the signal circuit end to end.
      • If 2 Ω or greater, repair the open/high resistance in the circuit.
      • Go to next step: If less than 2 Ω
    3. Test for infinite resistance between the signal circuit and ground.
      • If less than infinite resistance, repair the short to ground on the circuit.
      • If infinite resistance, replace the K20 Engine Control Module.
    • Go to next step: If greater than 95% 
  6. Test or replace the G13 Generator.
RENDER: 1.0x

NO RELATED

Recommended Tools & Savings

Use the Manual With the Right Hardware

Pair factory procedures with proven DIY tools so the instructions are easier to execute.

Affiliate disclosure: We may earn a commission at no extra cost to you.

Shop Manual-Ready ToolsFree Quote CheckQuote Shield Pro

When to See a Mechanic

Stop DIY work and contact a certified mechanic immediately if any of the following apply:

  • • You smell fuel, burning insulation, or see smoke.
  • • Brakes feel soft, pull hard to one side, or make grinding noises.
  • • The engine overheats, stalls repeatedly, or misfires under load.
  • • You are missing required tools, torque specs, or safe lifting equipment.
  • • You are not confident in the next step or safety outcome.