U1922 — Control Module Received Invalid Network Data

Diagnostic algorithm

1. Record failure conditions: note when the code set (driving, key ON, after start, temperature, etc.).
2. Use a scan tool to read U1922 details, related codes, freeze frame, and live data from all network modules.
3. If multiple U‑codes present, address persistent physical-layer faults first (shorts, opens, poor ground, terminations).
4. Visually inspect connectors, pins and harnesses for damage/corrosion at gateway, modules, and junction points.
5. Verify proper module power and ground voltages before testing network signals; repair any power/ground faults.
6. Measure resistance between CANH and CANL with ignition off to verify termination (~60 ohm).
7. With key ON, measure CANH and CANL DC voltages at multiple modules to check for correct idle levels (~2.5 V).
8. Use an oscilloscope or CAN analyzer to capture bus traffic: look for malformed frames, excessive error frames, stuck dominant/recessive states, or a single node flooding the bus.
9. If oscilloscope/trace indicates a noisy or corrupted signal, isolate sections of the bus by disconnecting modules (one at a time, per manufacturer guidance) to find the offending node.
10. If a specific module is identified as transmitting invalid data, verify software/calibration (reflash or update per TSB), check module grounds/power, and replace module if it fails bench/vehicle tests.
11. After repairs, clear codes and road test to confirm code does not return and that affected systems operate normally.
12. If no physical fault found and messages still invalid, consult manufacturer network topology and known service bulletins; some conditions require manufacturer diagnostics or gateway updates.