This diagnostic trouble code indicates that the engine control module (ECM) or powertrain control module (PCM) has received data from Body Control Module 'E' that is implausible, out of specified range, or fails a checksum validation. The code specifically points to a communication integrity issue rather than a mechanical failure, suggesting corrupted message content on the CAN bus network. It typically affects vehicles with multiple networked body control modules or zone-based electrical architectures.
The module's processor or transceiver may generate corrupted data packets due to internal electrical faults, memory corruption, or firmware errors, causing the ECM/PCM to flag the message as invalid despite proper voltage supply.
High resistance, corrosion, or terminal spread in the BCM E harness connectors, power feeds, or ground circuits can cause voltage fluctuations that corrupt data transmission integrity on the network.
Open circuits, short-to-ground, or short-to-voltage in the CAN high or CAN low lines between BCM E and the network backbone disrupt message packets and create invalid data signatures detectable by the receiving module.
Aftermarket electrical devices, faulty alternators, or welding repairs without proper battery disconnect can induce noise on communication lines, causing intermittent data corruption that triggers invalid data codes.
Incorrect flash programming or incomplete module updates following service can result in mismatched data protocols or message length mismatches between BCM E and the ECM/PCM.
Rarely, the receiving module may incorrectly interpret valid data due to internal hardware failure; this should only be considered after exhaustive verification of BCM E functionality, wiring integrity, and network topology.
Short-term driving is generally possible if the vehicle starts and critical systems function, but intermittent communication failures may strand the vehicle or disable security systems; diagnosis should be performed promptly to avoid unexpected breakdowns.
No; the PCM is rarely the cause of U0446. This code indicates the PCM is correctly detecting bad data from BCM E. Replacing the PCM typically wastes money because the root cause is almost always the BCM E itself, wiring issues, or network problems.
It designates the fifth body control module in a multi-module architecture, often corresponding to a specific zone controller (such as rear-body, door-module, or seat-module) in vehicles with distributed electrical systems, rather than the primary BCM.
Voltage transients during jump-starts or low-voltage conditions during battery swaps can corrupt volatile memory in BCM E or cause temporary communication errors; clearing the code and performing a network initialization may resolve it if no permanent hardware damage occurred.