P1E00 on Cadillac
Hybrid Powertrain Control Module Requested MIL Illumination
P1E00 on Cadillac vehicles indicates hybrid powertrain control module requested mil illumination. Au7o has documented this code across 1 Cadillac model — most commonly on ELR. This manufacturer-specific code (common on GM hybrids such as the Chevrolet Volt) means a hybrid powertrain control module has detected its own fault and requested that the engine computer turn on the check engine light (MIL). In other words, P1E00 is a 'pointer' code: it tells you a separate hybrid-system DTC has been stored elsewhere and is the real reason the light is on. The engine computer sets P1E00 in response to that request. To diagnose it, the underlying hybrid or battery system code(s) must be read and addressed. Typical repair costs on Cadillac range from $1,000 to $8,000, depending on the specific model and root cause.
Common Causes of P1E00
- •An underlying hybrid system DTC stored in another module
- •High-voltage battery or battery management fault
- •Motor/generator or inverter fault
- •Communication/serial data issue between modules
- •Software needing an update
- •Wiring or connector fault within the hybrid system
- •Faulty hybrid powertrain control module (rare)
P1E00 on Cadillac by Model
Cadillac ELR(2 issues)
- High-Voltage Battery Capacity Degradation and Reduced EV Range2014-2016
The Cadillac ELR (based on the Chevrolet Volt platform) uses a 16.5 kWh lithium-ion battery pack rated for 37 miles of EV range. Owners report noticeable capacity degradation after 5-7 years, with usable EV range dropping to 25-30 miles. The battery management system restricts capacity as cells degrade. While GM's Voltec system is generally more reliable than pure EV batteries due to active thermal management, the ELR's limited production means replacement battery modules are scarce and expensive.
- Onboard Charger and EVSE Communication Failures2014-2016
The ELR, based on the Chevrolet Volt platform, experiences onboard charger failures and communication issues with Level 2 EVSEs. The charging module may fail to initiate charging, stop mid-charge, or throw fault codes. The 120V Level 1 EVSE included with the car is also known to have reliability issues.
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View P1E00 across all makes →Frequently Asked Questions
What does P1E00 mean on Cadillac?▼
P1E00 stands for "Hybrid Powertrain Control Module Requested MIL Illumination." This manufacturer-specific code (common on GM hybrids such as the Chevrolet Volt) means a hybrid powertrain control module has detected its own fault and requested that the engine computer turn on the check engine light (MIL). In other words, P1E00 is a 'pointer' code: it tells you a separate hybrid-system DTC has been stored elsewhere and is the real reason the light is on. The engine computer sets P1E00 in response to that request. To diagnose it, the underlying hybrid or battery system code(s) must be read and addressed. On Cadillac specifically, this code is documented across 1 model.
What causes P1E00 on Cadillac vehicles?▼
Common causes on Cadillac: An underlying hybrid system DTC stored in another module, High-voltage battery or battery management fault, Motor/generator or inverter fault, Communication/serial data issue between modules, Software needing an update. Specific causes vary by model and year — see the per-model sections below.
How much does it cost to fix P1E00 on a Cadillac?▼
Repair costs on Cadillac range from $1,000 to $8,000, depending on the specific model and root cause.
Which Cadillac models have P1E00 documented?▼
Au7o has documented P1E00 on 1 Cadillac model: ELR.