Code
U0144
Generic
U — Network/User
Lost Communication With Body Control Module D
Views:
UK: 23
EN: 29
RU: 20
AI status
Completed
Completed
100%
Causes
- Faulty BCM D (internal failure)
- Battery or charging system low voltage or intermittent
- Poor or missing ground(s) to BCM D
- Corroded, loose, or damaged BCM D connector(s) or pins
- Open, shorted, or high-resistance wiring on CAN bus or dedicated LIN/wake circuits
- Failed CAN bus transceiver or other network module driving the bus
Symptoms
- One or more body systems inoperative (lights, locks, windows, wipers, alarm/immobilizer)
- Instrument cluster or other modules reporting communication errors
- No response or incomplete data from BCM D in a scan tool
- Intermittent operation of convenience features
- Multiple related DTCs stored in other modules referencing lost communication
What to check
- Use a capable scan tool to confirm U0144 and check for related U‑codes in other modules
- Record freeze frame and event counters, and note whether the fault is active or intermittent
- Check battery voltage and charging system (key ON, engine OFF and while cranking/running)
- Visually inspect BCM D connector, pins, and harness for corrosion, bent pins, or water intrusion
- Verify BCM D ground(s) for tightness and low resistance to chassis/negative battery
- Measure CAN bus voltages (CAN H and CAN L) at the BCM connector with key ON
Signal parameters
- CAN bus recessive idle voltage: CAN H ≈ 2.5 V, CAN L ≈ 2.5 V (typical)
- CAN bus dominant state: CAN H ≈ 3.5 V, CAN L ≈ 1.5 V (differential ≈ 2 V)
- Differential voltage (CANH − CANL) idle ≈ 0 V, dominant ≈ 2 V
- Termination resistance across CAN H and CAN L ≈ 60 Ω (two 120 Ω terminators in parallel)
- Battery voltage at BCM with key ON ≈ 12–14.5 V
Diagnostic algorithm
- Connect a diagnostic scan tool, verify U0144, note whether code is current or historical, and check for related codes in other modules.
- Verify battery voltage and charging system. Recharge or replace weak battery and ensure battery terminals are clean and tight.
- Inspect BCM D connector and harness for contamination, corrosion, bent pins, or water ingress. Repair or replace connector as needed.
- Verify ground(s) for BCM D: remove, clean contact surfaces, and measure resistance to battery negative (should be very low).
- With key ON, measure CAN H and CAN L at the BCM connector. Compare to expected values. If voltages are abnormal, isolate to wiring or other modules.
- Measure termination resistance across CAN H and CAN L at two points on the bus (expect ≈60 Ω). If open or shorted, locate missing/shorted terminator.
- Inspect and test wiring continuity between BCM D and other modules or the next connector on the CAN ring. Repair any opens, shorts to ground, or shorts to battery.
- If CAN signals look correct at the BCM connector but module does not respond, check power supply pins (constant and switched B+) and wake/ignition inputs for correct voltages.
- Check for bus traffic using a scope or CAN bus analyzer. Confirm whether BCM D transmits any messages or whether bus traffic stops when BCM is connected/disconnected.
- If wiring, power, grounds, and bus health are confirmed good and the BCM still fails to communicate, check for software updates/TSBs and consider replacing BCM D as a last step. Reprogram replacement module per manufacturer procedure.
- Clear codes and retest all affected systems. Monitor for recurrence and verify repair.
Likely causes
- Loose or corroded connector at BCM D
- Damaged CANH/CANL wiring near BCM D
- Bad ground at BCM D or shared ground point
- Low battery or poor battery connections causing sleep/wake faults
- Failed BCM D module
Fault status
Status
Lost Communication With Body Control Module D — No valid messages received from BCM D on the vehicle network (CAN/LIN).
Repair difficulty: Medium
Diagnostic time: 1.0-3.0 hours
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