P2E85

Code

Generic P — Powertrain

Battery Charger B Input Voltage Sensor Circuit Low

Brand: Generic

Type: P — Powertrain

Views: UK: 25 EN: 36 RU: 26

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Page language: EN

Causes

Open or shorted wiring between sensor and control module
Corroded, loose, or damaged connector at the sensor or module
Faulty Battery Charger B input voltage sensor
Blown fuse or faulty relay powering the charger or sensor circuit
Low system battery or weak auxiliary supply to the sensor circuit
Poor ground or high resistance in grounding circuit

Symptoms

Charge system warning lamp or message illuminated
Reduced or no charging from Charger B
Slower-than-expected state-of-charge increase
Stored DTC and/or limp-home charging behavior
Possible erratic state-of-charge (SOC) indications or charging interruptions

What to check

Retrieve freeze frame and live data with a scan tool; note sensor voltage and related values
Visual inspection of wiring, connectors, and charger module for damage or corrosion
Check related fuses and relays for continuity and proper operation
Measure sensor circuit voltage at the sensor connector (key on, engine off) with a DVOM/oscilloscope
Check reference supply voltage and ground at the sensor harness connector
Perform wiggle/drive test to see if the fault is intermittent

Signal parameters

Typical sensor output: 0–5.0 V analog signal to controller (may vary by vehicle)
Low threshold: controller flags fault when sensor voltage is below approx. 0.1–0.5 V (manufacturer-dependent)
Normal operating range: roughly 0.5–4.8 V depending on measured input voltage
Reference supply to sensor: usually ignition-switched 5 V or battery-derived supply (verify specific vehicle)
Impedance: expect low source impedance; large resistance in harness/ground will distort reading

Diagnostic algorithm

Read and record DTCs and freeze frame data with a scan tool. Note conditions when fault set (ignition state, vehicle voltage).
Clear the code and attempt to reproduce. If intermittent, perform extended road test while monitoring live data.
Visually inspect the Battery Charger B harness, connectors, and charger module for damage, corrosion, or loose pins.
Verify fuse(s) and relay(s) that supply the charger and sensor circuit. Replace any blown fuses and retest.
With the ignition ON (engine OFF unless otherwise specified), backprobe the sensor connector and measure the signal voltage. Compare to expected range.
Verify the sensor reference supply voltage and ground at the connector. Check continuity from sensor ground to chassis ground and module ground.
If signal is low at the sensor, trace back toward the controller: check harness continuity and look for short to ground. If open circuit, repair wiring/connectors.
If signal is correct at the sensor but low at the controller input, inspect/repair harness between sensor and controller. Check for corrosion or connector faults at the controller.
If wiring and connectors are good but signal remains abnormal, replace the Battery Charger B input voltage sensor (or charger module) and retest.
If replacement parts do not correct the condition, check controller power/ground and consider controller software update or replacement per manufacturer procedures.
After repairs, erase DTCs and verify the system returns to normal operation under the same conditions that originally set the code.