LEMON Manuals: Even more car manuals for everyone: 1960-2025
Home >> Cadillac >> 2014 >> Escalade ESV Base, AWD >> Repair and Diagnosis >> Engine Performance >> System >> Data Communication System >> Diagnostic Information and Procedures >> DTC U1821: Lost Communication With DC to DC Converter Control Module A on Bus B >> Diagnostic Fault Information
April 5, 2026: LEMON Manuals is launched! Read the announcement.

Diagnostic Fault Information

Circuit Short to Ground Open/High Resistance Short to Voltage Signal Performance
B+ U1821* U1821 - -
Ground - U1821* - -
PTLAN + U0074* U1821, 1 U0074* -
PTLAN - U0074* U1821, 1 U0074* -
* Other modules/DTCs may set with this fault.
1. Multiple DTCs including U1821 may set and multiple symptoms including a no start condition may occur.
scientia non olet · About LEMON Manuals