B10A8

Code

Generic B — Body

Driver Door Module Communication Fault

Brand: Generic

Type: B — Body

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AI status

Completed

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Page language: EN

Causes

Open or shorted wiring between DDM and gateway/BCM
Poor connector pin contact, corrosion or water intrusion at the DDM connector
No battery power or poor ground to the DDM
Failed DDM (internal hardware or software fault)
Bus faults (CAN or LIN) such as missing termination, short to battery/ground
Module configuration or software mismatch after replacement or update

Symptoms

Loss or intermittent operation of driver door functions (power windows, mirror adjust, door locks, courtesy lights)
Door-related warnings or 'Check Door' messages on dash
Other modules reporting lost communication with DDM on a scan tool
Model-specific features tied to DDM (keyless entry, memory settings) not working
DTC B10A8 present and may reappear after clearing

What to check

Connect a scan tool and read all stored and pending codes and freeze frame data
Check live data/messages from the DDM and related modules for presence and timing
Visually inspect DDM connector and wiring at the driver door and hinge area for damage or corrosion
Verify DDM supply voltage (pin battery feed) with ignition on: should be ~11–14 V
Verify DDM ground(s) for low resistance to chassis (
Measure CAN bus voltages: CAN_H ~2.5 V idle, CAN_L ~2.5 V idle; dominant state typically CAN_H ~3.5 V and CAN_L ~1.5 V

Signal parameters

DDM supply voltage: 11.0–14.5 V with ignition ON
DDM ground resistance:
CAN_H idle voltage: ~2.5 V
CAN_L idle voltage: ~2.5 V
CAN dominant state: CAN_H ~3.5 V, CAN_L ~1.5 V (differential ~2.0 V)
Bus termination (CAN_H to CAN_L): ~60 Ω (two 120 Ω terminators in parallel)

Diagnostic algorithm

Record all DTCs and freeze-frame data with a capable scan tool. Note occurrence conditions and any related network codes.
Reproduce the symptom if safe. Monitor live data for DDM message frequency and related module responses while operating door functions.
Visually inspect driver door harness, grommet/boot at hinge, and DDM connector for damage, corrosion, or intrusion of water. Repair any obvious physical damage.
With connector engaged, measure DDM supply(s) and ground(s). Repair blown fuses, loose power feeds, or poor grounds before further testing.
Check the vehicle network: measure CAN_H/CAN_L voltages at the DDM connector with ignition ON. Verify termination resistance between CAN_H and CAN_L with ignition OFF.
If bus voltages or termination are out of range, isolate sections of the network (disconnect other modules or harness segments as required) to locate short or open.
Perform a wiggle test on the door harness while watching for message loss or DTC set; check continuity on suspect circuits if intermittent behavior is observed.
If wiring and power/ground check good but messages are absent, attempt module wake-up/identify using the scan tool. Verify module software part number and calibration level versus manufacturer specs.
If software mismatch or corrupted software is suspected, reflash/reprogram the DDM or gateway per manufacturer procedures and re-test.
If module still fails communication after power/ground, wiring, and bus checks, consider replacing the DDM. After replacement, program/configure and retest all functions and clear codes.
Clear DTCs and perform a road/usage test to verify fault does not return. If intermittent faults persist, use scope-level diagnostics on the network and consult manufacturer service information.

Likely causes

Corroded or loose connector pins at driver door module
Broken or chafed wiring in the door harness from repeated opening/closing
Blown inline fuse or fused feed to the DDM
Faulty ground strap or high-resistance ground at door or hinge
Bus termination missing or shorted (failed resistor or connection)
Failed DDM due to water ingress or internal component failure

Fault status

⚠️ Status

Driver Door Module communication fault — module not responding or messages missing on vehicle network. Check power, ground, connectors, and bus wiring.

🟡 Repair difficulty: Medium

⏱️ Diagnostic time: 1.0-2.5 hours