Circuit/System Testing

WARNING: This page is about a different variant/trim than selected.

Ignition/Vehicle & All vehicle systems - Off
Disconnect the electrical connector: X1 @ K20 Engine Control Module
Verify a test lamp turns On between the test points: B+ circuit terminal 1 & Ground
- If the test lamp does not turn On and the circuit fuse is OK
1. Ignition/Vehicle - Off & Remove - Test lamp
2. Test for less than 2 ohms between the test points:
  - {Escalade} B+ circuit terminal 1 & Output terminal @F5UD Fuse
  - {Sierra/Silverado/Tahoe/Yukon} B+ circuit terminal 1 & Output terminal @F5BA Fuse
  - If 2 ohms or greater - Repair the open/high resistance in the circuit.
  - If less than 2 ohms - Verify the fuse is OK and there is voltage at the fuse.
- If the test lamp does not turn On and the circuit fuse is open
1. Ignition/Vehicle - Off & Remove - Test lamp
2. Test for infinite resistance between the test points: B+ circuit terminal 1 & Ground
  - If less than infinite resistance - Repair the short to ground on the circuit.
  - If infinite resistance - Replace the component: K20 Engine Control Module
- Go to next step: If the test lamp turns On
Replace the component: K20 Engine Control Module