U059A

Code

Generic U — Network/User

Invalid Data Received From DC/DC Converter Control Module B

Brand: Generic

Type: U — Network/User

Views: UK: 23 EN: 29 RU: 23

AI status

Completed

ready

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Page language: EN

Causes

Corroded, loose, damaged or poor connector or wiring to DC/DC Converter Control Module B
Power (battery or ignition) or ground problem at the DC/DC converter control module
Faulty DC/DC Converter Control Module B (internal electronics or firmware)
CAN bus physical layer faults (shorts, opens, high resistance, missing termination)
Intermittent wiring harness movement or contact resistance
Software mismatch or corrupted module programming

Symptoms

Charge/charging system or 12V electrical warning lamp illuminated
Intermittent or sustained loss of 12V bus charging (low battery voltage)
Reduced vehicle electrical function, limp-home mode, or limited accessory operation
Multiple communication-related DTCs present (U-codes)
Erratic gauge or instrument cluster readings related to 12V/charge
Possible vehicle won't start if 12V is not maintained

What to check

Retrieve all stored U- and P-codes and freeze-frame data with a capable scan tool
Check for additional communication or invalid-data codes on the same CAN network
Visually inspect connectors and wiring to DC/DC Converter Control Module B for damage, corrosion, or loose pins
Verify module supply power and ground at the DC/DC converter control connector with a multimeter
Check CAN bus physical layer: measure dominant/recessive voltages and look for shorts or opens
Monitor live CAN messages and data fields from the DC/DC converter module using a scan tool or CAN bus sniffer

Signal parameters

CAN message ID(s) used by DC/DC Converter Control Module B (vehicle-specific — verify in service literature)
Message cycle time / expected send frequency (e.g., 10–1000 ms depending on parameter)
Data Length Code (DLC) and expected byte layout for the DC/DC messages
DC-DC converter 12V output voltage (expected ~11–15 V for 12V bus systems)
DC-DC converter status bits (enable, fault, standby, interlock states)
Reported DC-DC output current or charge current (should be within manufacturer limits)

Diagnostic algorithm

Connect a full-function scan tool. Read and record all stored and pending codes, freeze-frame data, and live data from the DC/DC converter and related modules.
Note whether the code is active, historic, or intermittent. Reproduce conditions that set the code if safe (key cycle, load/electrical accessory on/off, drive/run conditions).
Inspect the DC/DC converter control module connector(s) and harness for damage, corrosion, bent pins, or water intrusion. Repair any physical faults and clear codes to retest.
With ignition on, measure supply voltage and ground integrity at the DC/DC converter control module connector. Repair poor supply/ground connections before further testing.
Check the vehicle CAN bus: use a scan tool to view message traffic and a scope or DMM to confirm CAN-H/CAN-L voltages and termination resistances. Repair any bus wiring faults.
Monitor the specific CAN message(s) from DC/DC Converter Control Module B. Verify message frequency, DLC, and data field ranges (voltage, current, status bits). Identify which field is invalid.
If messages are malformed (bad CRC, wrong format) or fields are out-of-range while wiring and power are good, consider module internal fault or corrupted software. Check for manufacturer updates or TSBs.
If available and safe, try module reset, power-cycle, or reflash to the latest calibration per service procedures. Re-scan and road/test to confirm resolution.
If code returns after verifying wiring, power, bus integrity and software, replace DC/DC Converter Control Module B following vehicle-specific procedures and retest.
After repair, clear codes, perform required relearn procedures (if any), and confirm no recurrence under all applicable operating conditions.
Safety: when working on high-voltage systems (if present), follow vehicle manufacturer HV isolation and lockout/tagout procedures.

Likely causes

Poor connector, pin corrosion, or broken wire at the DC/DC converter control module
CAN bus communication errors caused by missing/failed termination or short to battery/ground
DC/DC converter module fault or internal sensor failure returning invalid telemetry
Module software update or configuration mismatch after a service or replacement

Fault status

⚠️ Status

Invalid data received from DC/DC Converter Control Module B — message format, checksum, timing, or field values outside expected parameters. Status may be active (present), pending/intermittent, or historic depending on occurrence and system diagnostics.

🟡 Repair difficulty: Medium

⏱️ Diagnostic time: 0.5-3.0 hours