Code
B0734
HUMMER
B — Body
Body Control Module: Invalid Data Received (B0734)
AI status
Completed
Completed
100%
Causes
- Corroded, loose or damaged connector at the BCM or a related module
- Open, shorted or intermittent wiring on CAN, LIN or sensor circuits
- Failed or misconfigured BCM software/firmware (calibration mismatch)
- Faulty node on the vehicle network (another module sending malformed messages)
- Low battery voltage or poor ground affecting data transmissions
- Blown fuse or intermittent power supply to BCM
Symptoms
- Illumination of body control or communication warning lamps
- One or more body functions inoperative or erratic (doors, locks, lighting, wipers)
- Intermittent loss of communication with BCM on a diagnostic tool
- Stored or pending communication-related DTCs (BCM or other modules)
- Modules reporting implausible sensor values or random faults
What to check
- Read and record all stored DTCs and freeze-frame data from BCM and other modules
- Check battery voltage (with engine off and cranking) and state of charge; ensure stable supply (12.4–12.9V nominal resting)
- Inspect BCM and adjacent connectors for corrosion, bent pins, water ingress, or loose fasteners
- Verify fuses and relays for BCM power/ignition circuits
- Scan other modules for related communication codes (U-codes)
- Visually inspect CAN/LIN wiring for chafe, pinch points, broken insulation, or recent repair splices
Signal parameters
- CAN bus voltage (idle ~2.5V differential on CAN_H/CAN_L pair) and bus common mode
- CAN message IDs and frequency expected from known nodes (messages per second)
- Presence and timing of BCM wake/sleep messages
- Specific data bytes in BCM-related messages (compare to known good vehicle or manufacturer data)
- Ground voltage at BCM connector (should be near 0V) and supply voltage at BCM power pin
- Error frame count or bus error rates if available on scan tool or oscilloscope
Diagnostic algorithm
- Record all DTCs from BCM and other modules; note occurrence counters and freeze frame. Check for related U-codes indicating network issues.
- Verify battery state and charging system. If battery voltage is low or unstable, charge or replace before further testing.
- Visually inspect BCM connectors, harness routing and nearby components for damage, corrosion, moisture or recent repair work. Repair any damaged wiring or connectors.
- Check BCM power and ground pins for correct voltage and low resistance to chassis ground. Repair poor power/ground connections.
- Use a scan tool to monitor CAN/LIN activity. Verify expected message IDs and frequencies. Note missing or malformed messages.
- If bus activity is suspect, use an oscilloscope to inspect CAN_H/CAN_L waveforms for noise, reflections or error frames. Verify proper termination resistances.
- Isolate suspected nodes by disconnecting modules one at a time (where safe and manufacturer-approved) to see if invalid data source clears.
- If wiring and external modules check good, check BCM software level against manufacturer specifications. Reflash/update BCM software per manufacturer procedures if an update or reprogramming is recommended.
- After repairs or software work, clear codes and perform functional tests and road test to confirm no recurrence. Monitor for intermittent faults over drive cycles.
- Replace BCM only if all network, wiring, power/ground and software options have been exhausted and the BCM is confirmed faulty per manufacturer diagnostic criteria.
Likely causes
- Intermittent CAN bus wiring fault between BCM and gateway/module
- Corrosion or bent pins at BCM connectors causing data bit errors
- Outdated or corrupted BCM software after previous repairs or battery disconnect
- Another control module failing and placing bad messages onto the network
- Poor battery/charging system voltage during communications
Fault status
Status
BCM has received invalid/malformed data on a network or input circuit causing data integrity/communication fault.
Repair difficulty: Medium
Diagnostic time: 1.5 - 4.0 hours
Similar codes
Repair manuals
Manual library for HUMMER
138
Browse 138 HUMMER manuals: repair procedures, diagnostics, wiring diagrams, component locations, service data and Labor Times by year, model and trim.
HUMMER
-
HUMMER: 2009
-
HUMMER: 2008
-
HUMMER: 2007
-
HUMMER: 2005
-
HUMMER: 2004
-
HUMMER: 2000
-
HUMMER: 1999
-
HUMMER: 1994
-
HUMMER: 1993
Your experience will help others
+100 karma for a short comment :)
Was this AI description helpful?
Your feedback helps improve AI descriptions.
👍 Like
0
👎 Dislike
0
Send to email