P2E84

Code

Generic P — Powertrain

Battery Charger B Input Voltage Sensor Circuit Range/Performance

Brand: Generic

Type: P — Powertrain

Views: UK: 16 EN: 23 RU: 16

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Page language: EN

Causes

Open or short in Battery Charger B input voltage sensor circuit
Corroded, loose or damaged connector(s) at the charger, sensor or ECU
Failed battery charger input voltage sensor or charger/control module
High resistance/poor ground in the sensor/charger circuit
Intermittent wiring fault from chafing, pinched harness or water intrusion
Battery pack or main battery voltage abnormal that moves sensor outside expected range

Symptoms

DTC P2E84 stored or a charger/charge system warning lamp/message displayed
Reduced or disabled charging for Charger B (may show reduced battery state-of-charge)
Possible related limp or reduced-power charging strategy from vehicle control module
Erratic state-of-charge readings or charging current inconsistent with battery voltage
No start may occur on some systems if charge management disabled (rare)

What to check

Read freeze frame and live data with a capable scan tool to capture sensor voltage and related parameters
Visually inspect charger, harness, and connectors for damage, corrosion, water intrusion and pin deformation
Backprobe the Battery Charger B input sensor pin at the charger and at the ECU (or harness connector) and compare voltages
Measure connector continuity and resistance between charger input sensing pin and ECU pin with ignition off
Check for a reliable chassis and battery ground at charger/module mounting points
Use an oscilloscope to look for intermittent signals or noise if available

Signal parameters

Typical sensor interface: low-voltage analog 0–5.0 V signal to ECU (vehicle dependent)
Normal operating voltage usually tracks pack/battery voltage scaled into 0.8–4.2 V range (varies by design)
Fault thresholds (example): low 4.8 V indicates short-to-battery or open pull-up (manufacturer dependent)
Expected response: sensor voltage should follow battery/charger input voltage changes when engine/charger is active
If using CAN / digital messages: check that Charger B status and measured voltages appear and update at expected message intervals

Diagnostic algorithm

Retrieve all related codes and freeze-frame data. Note conditions when DTC set (ignition/charging state/temperature).
Clear codes and attempt to reproduce while monitoring live sensor voltage, charger output current, battery voltage and related CAN messages.
Perform visual inspection of Battery Charger B, harness and connectors. Look for corrosion, heat damage, chafing, water entry, or broken wires.
With ignition ON (charger enabled state if required), backprobe the Battery Charger B input sensor pin at the charger connector and at the ECU harness connector. Record voltages and compare to battery/pack voltage.
Check reference and ground: verify ECU reference voltage (if used) and all grounds for the charger/module are present and low resistance. Repair any high-resistance grounds.
Perform continuity and resistance checks between charger sensor pin and ECU pin with ignition OFF. Look for opens or shorts to ground/Vbatt. Wiggle harness to check for intermittent faults.
If DMM readings are ambiguous, use an oscilloscope to detect noise, dropouts or intermittent spikes on the sensor line while cycling charger/engine on and off.
If circuit and wiring check good, swap or bench-test the charger module or sensor (if serviceable) per manufacturer procedure, or replace the charger/module and retest.
After repair, clear codes and road/test or run charger cycles long enough to confirm the fault does not return. Re-scan to verify no additional codes triggered.

Likely causes

Wiring open or short to ground/Vbatt at the charger B input sensor circuit
Corroded/loose connector pin at charger or ECU harness
Failed voltage-sensing circuit in the charger module or sensor
High-resistance ground at the charger or module ground stud
Intermittent fault due to harness abrasion or connector moisture intrusion

Fault status

⚠️ Status

Battery Charger B input voltage sensor signal is outside expected range or not performing correctly. Check charger input sensor circuit, wiring, connectors, and module.

🟡 Repair difficulty: Medium

⏱️ Diagnostic time: 0.5-2.5 hours