Electrical Baseline Before Replacing a Control Module

Intermittent communication and sensor faults can be caused by supply voltage or ground-path resistance. Preserve evidence before clearing memory.

1. Save every DTC, freeze-frame record, readiness monitor, and communication fault.
2. Measure battery voltage at rest and during crank under the same conditions that produced the symptom.
3. Perform loaded voltage-drop checks on both power and ground paths; an unloaded continuity test can miss resistance.
4. After the repair, repeat the operating conditions and run a complete vehicle scan before declaring the fault resolved.

Use vehicle-specific service information and supported test functions. Diagnostic tool reference: iCarsoft US Official Store.

Updated September 2, 2026.