U0100 on Jeep
Lost Communication with ECM/PCM
U0100 on Jeep vehicles indicates lost communication with ecm/pcm. Au7o has documented this code across 1 Jeep model — most commonly on Grand Wagoneer. U0100 is a network communication code meaning a module has lost communication with the engine control module / powertrain control module (ECM/PCM) over the vehicle's data bus. The ECM/PCM is the brain that runs the engine, so when other modules can no longer 'talk' to it, the effects can be serious — a no-start, stalling, multiple warning lights, and many other modules logging faults at once. This is almost always a wiring, connector, power/ground, or bus fault, or a failure of the ECM/PCM itself, rather than a single sensor. It should be diagnosed promptly because the vehicle may be undrivable. Typical repair costs on Jeep range from $200 to $1,800, depending on the specific model and root cause.
Common Causes of U0100
- •Loss of power or ground to the ECM/PCM
- •CAN bus wiring damage, short, or open circuit
- •Corroded, loose, or damaged connectors at the module
- •Blown fuse feeding the ECM/PCM
- •Failed ECM/PCM
- •Another faulty module pulling down the data bus
- •Water intrusion or corrosion in a connector/harness
U0100 on Jeep by Model
Jeep Grand Wagoneer(1 issue)
- Battery drain / no-start due to telematics or module staying awake (parasitic draw)2022-2024
Owner reports and NHTSA complaints describe repeated dead 12V batteries and no-start conditions on Grand Wagoneer, often after sitting overnight or a few days. The pattern is consistent with parasitic draw from modules not going to sleep (commonly telematics/infotainment-related controllers), leading to low voltage and cascading network faults.
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What does U0100 mean on Jeep?▼
U0100 stands for "Lost Communication with ECM/PCM." U0100 is a network communication code meaning a module has lost communication with the engine control module / powertrain control module (ECM/PCM) over the vehicle's data bus. The ECM/PCM is the brain that runs the engine, so when other modules can no longer 'talk' to it, the effects can be serious — a no-start, stalling, multiple warning lights, and many other modules logging faults at once. This is almost always a wiring, connector, power/ground, or bus fault, or a failure of the ECM/PCM itself, rather than a single sensor. It should be diagnosed promptly because the vehicle may be undrivable. On Jeep specifically, this code is documented across 1 model.
What causes U0100 on Jeep vehicles?▼
Common causes on Jeep: Loss of power or ground to the ECM/PCM, CAN bus wiring damage, short, or open circuit, Corroded, loose, or damaged connectors at the module, Blown fuse feeding the ECM/PCM, Failed ECM/PCM. Specific causes vary by model and year — see the per-model sections below.
How much does it cost to fix U0100 on a Jeep?▼
Repair costs on Jeep range from $200 to $1,800, depending on the specific model and root cause.
Which Jeep models have U0100 documented?▼
Au7o has documented U0100 on 1 Jeep model: Grand Wagoneer.