P3000 on Cadillac
Hybrid/High-Voltage Battery Control System Malfunction (Parent Code)
P3000 on Cadillac vehicles indicates hybrid/high-voltage battery control system malfunction (parent code). Au7o has documented this code across 1 Cadillac model — most commonly on ELR. P3000 is a high-voltage battery malfunction code used mainly on hybrid vehicles (commonly Toyota and Lexus), set when the hybrid/battery control system detects an abnormality in the HV battery pack or its monitoring system. It is intentionally a generic 'parent' code — the specific fault (weak cell block, cooling problem, communication loss, contactor issue) is identified by accompanying sub-codes (INF codes). It can cause warning lights, reduced hybrid assist, or the vehicle refusing to enter Ready mode. Because it involves the high-voltage system, it is important and usually needs hybrid-capable diagnostic equipment. Typical repair costs on Cadillac range from $25 to $400, depending on the specific model and root cause.
Common Causes of P3000
- •Weak or degraded HV battery cell block/module
- •Battery cooling fan failure or blocked cooling airflow
- •Loss of CAN communication between battery ECU and hybrid ECU
- •Battery ECU / battery management system fault
- •Stuck contactor or insulation (leak/short) fault
- •Corroded or loose HV battery connections/bus bars
- •Aging high-mileage hybrid battery pack
P3000 on Cadillac by Model
Cadillac ELR(1 issue)
- 'Service High Voltage Charging System' Message from Low Battery Coolant or Failed Coolant Level Sensor2014-2016
The ELR uses a dedicated liquid loop to thermally manage the high-voltage battery, with a coolant level sensor in the HV battery reservoir on the driver's side of the engine bay. A low coolant level - or, very commonly, a failing coolant level sensor or its jumper harness with internal wire breaks - triggers a 'Service High Voltage Charging System' (SHVCS) message, often setting P3000 and disabling charging. This is a well-known Voltec failure that has migrated from the Chevy Volt to the higher-mileage ELR fleet. Left unaddressed it can interrupt charging and, in conjunction with thermal-management faults, contribute to reduced-propulsion behavior.
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View P3000 across all makes →Frequently Asked Questions
What does P3000 mean on Cadillac?▼
P3000 stands for "Hybrid/High-Voltage Battery Control System Malfunction (Parent Code)." P3000 is a high-voltage battery malfunction code used mainly on hybrid vehicles (commonly Toyota and Lexus), set when the hybrid/battery control system detects an abnormality in the HV battery pack or its monitoring system. It is intentionally a generic 'parent' code — the specific fault (weak cell block, cooling problem, communication loss, contactor issue) is identified by accompanying sub-codes (INF codes). It can cause warning lights, reduced hybrid assist, or the vehicle refusing to enter Ready mode. Because it involves the high-voltage system, it is important and usually needs hybrid-capable diagnostic equipment. On Cadillac specifically, this code is documented across 1 model.
What causes P3000 on Cadillac vehicles?▼
Common causes on Cadillac: Weak or degraded HV battery cell block/module, Battery cooling fan failure or blocked cooling airflow, Loss of CAN communication between battery ECU and hybrid ECU, Battery ECU / battery management system fault, Stuck contactor or insulation (leak/short) fault. Specific causes vary by model and year — see the per-model sections below.
How much does it cost to fix P3000 on a Cadillac?▼
Repair costs on Cadillac range from $25 to $400, depending on the specific model and root cause.
Which Cadillac models have P3000 documented?▼
Au7o has documented P3000 on 1 Cadillac model: ELR.