Circuit/System Testing
WARNING: This page is about a different variant/trim than selected.
- Ignition/Vehicle & All vehicle systems - Off
- Verify the fuse is not open: F90UA Fuse@X50A Fuse Block - Underhood
- If the fuse is open
- Disconnect the electrical connector: X1@K20 Engine Control Module
- Test for infinite resistance between the test points: Output terminal@F90UA Fuse & 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 fuse is not open
- Disconnect the electrical connector: X1@K20 Engine Control Module
- Test for less than 2 ohms between the test points:
- {Sierra/Silverado} Ignition circuit terminal 46@Control module harness & Output terminal@F90UA Fuse
- {Escalade/Tahoe/Yukon} Ignition circuit terminal 69@Control module harness & Output terminal@F90UA Fuse
- If 2 ohms or greater
Repair the open/high resistance in the circuit.
- Go to next step: If less than 2 ohms
- Replace the component: K20 Engine Control Module
NOTE:
A high resistance condition on the component circuits may cause the DTC to set.