P2D6B

Code

Generic P — Powertrain

Battery Charging System Positive Contactor D Stuck Open

Brand: Generic

Type: P — Powertrain

Views: UK: 22 EN: 32 RU: 21

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Page language: EN

Causes

Contactor D mechanical failure (welded, bent, or jammed contacts)
Contactor coil open or shorted
Contactor coil not being powered (blown fuse, open circuit, poor connector)
High-voltage or low-voltage wiring harness damage or corrosion
Control module/BMS driver fault or software issue preventing command
Safety interlock preventing contactor closure (service plug, emergency disconnect, insulation fault, traction relay state, etc.)

Symptoms

Cannot start charging or charging stops prematurely
Charging current is zero or greatly reduced when charge is commanded
Charging-related warning or charge inhibit lamp/message on dash or infotainment
Stored DTC P2D6B (may be accompanied by other HV contactor DTCs)
No audible click from the contactor when a charge is requested (if audible)
Vehicle may not enable HV systems or may enter limp mode

What to check

Read and record freeze frame and related codes with a scan tool (check BMS/hybrid system data)
Visually inspect contactor, connectors, harness, fuses, service disconnect and any visible HV interlocks for damage or corrosion
Confirm whether the service disconnect/service plug is installed correctly and no safety interlocks are active
Using a scan tool, command Contactor D to close while monitoring status bits and look/listen for operation (follow vehicle safety procedures)
Check for related fuses/relays in low-voltage circuits that feed the contactor coil
Check for presence of auxiliary/logic battery voltage at the contactor coil connector when commanded (do not probe HV terminals without appropriate HV isolation and PPE)

Signal parameters

Command input: Contactor D command status = Open (0) or Closed (1) from BMS/ECU (expected = Closed during charging)
Coil supply (low-voltage control) when commanded: typically the vehicle low-voltage system (approx. 9–16 V depending on system) — confirm manufacturer spec
Coil resistance: expected to be finite and stable (typically tens to hundreds of ohms; refer to vehicle spec)
Contact continuity: Open = infinite/OL; Closed = near 0 Ω across positive battery feed and charging bus (measure only with HV system made safe)
Feedback/status circuits (if equipped): position sensor or feedback bit should change state when contactor is commanded closed

Diagnostic algorithm

Connect a capable scan tool and record all HV system codes, freeze frame, and live data for contactor states and command bits.
Verify safety: follow vehicle manufacturer high-voltage isolation and PPE procedures before performing any hands-on checks involving HV components.
Visual inspection: check contactor assembly, connectors, harness, fuses, service plug, and visible wiring for damage, corrosion, or disconnections.
Attempt a commanded close via scan tool while observing the contactor status bit and listening for an audible click. If the contactor closes and status changes, monitor for intermittent behavior.
If no operation when commanded, measure low-voltage control supply at the contactor coil connector while commanded (verify presence of required control voltage and ground). If control voltage absent, trace back fuses, relays, and ECU/BMS driver outputs.
If control voltage is present but contactor does not close, do not probe HV main terminals. With HV system made safe per manufacturer procedure, check contactor coil resistance and continuity across main contacts when commanded closed. Replace contactor if contacts do not close or coil is out of spec.
If coil and contactor appear functional, inspect driver circuitry in the BMS/ECU and related wiring for opens/shorts or software faults. Consider module reprogramming or replacement per service information.
After repair or replacement, clear DTCs, perform a full charging test and monitor for recurrence. Verify all safety interlocks and insulation monitoring are within specification.

Likely causes

Contactor coil not receiving proper supply or ground (connector corrosion, blown fuse)
Contactor mechanically stuck open/welded contacts
Open or high-resistance wiring between contactor and battery/ECU
Contactor driver (BMS/ECU) failing to command close
System safety interlock (service plug removed, HV fault) preventing closure