Gear shift stalls or won’t move and U0103 lights on your car—lost communication with Gear Shift Control Module A. Scan, reprogram or replace module.

Your vehicle won’t engage 4WD, U0102 code. Lost communication with the Transfer Case Control Module disables 4WD. Scan wiring, then re‑program the module.

Lost TCM communication (U0101) in your vehicle can cause shift loss and safety risk. Scan, test wiring, then repair or reprogram the TCM promptly.

Your vehicle won’t start? Lost communication with ECM/PCM A disables engine control—run a network scan, inspect wiring, and arrange repair/reprogramming.

Communication bus error on your vehicle? U0099 means H‑ bus voltage is high—possible module loss. Scan, check wiring, then reprogram or replace the bus.

Vehicle Communication Bus H (-) low on your vehicle? It can disable safety and body‑control features. Scan the bus, inspect wiring, and reprogram module.

Communication bus H (-) open on your vehicle? Loss of BCM functions can disable lights and locks—diagnose the wiring or module, then reprogram or replace.

Glitchy lights or lock issues on your vehicle? A high voltage on Communication Bus H (+) can cut module communication—scan, test wiring, and reprogram.

Flickering lights or erratic electronics in your vehicle? A low H‑bus (+) voltage can disable critical modules. Scan, test the bus and reprogram.

Your vehicle windows, locks or lights fail? A U0094 Bus H (+) Open cuts key functions—scan, check wiring and reprogram or replace the bus module.