U0100 on Chrysler
Lost Communication with ECM/PCM
U0100 on Chrysler vehicles indicates lost communication with ecm/pcm. Au7o has documented this code across 1 Chrysler model — most commonly on Pacifica. 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.
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 Chrysler by Model
Chrysler Pacifica(1 issue)
- Loose Battery Ground Connection Causing Stall and Loss of Power Steering Assist (Stop/Start)2017-2019
On Pacificas built with the engine stop/start system, sealer left on the wire-harness tab during harness manufacturing sits inside the battery ground joint. Over time the sealer creeps and the joint loses clamp load, so the main chassis/engine ground goes intermittent. The high current draw of stop/start restarts makes it worse. Drivers get sudden electrical dropouts: the engine stalls at speed, electric power steering assist cuts out, and a cluster full of warning lights appears. FCA recalled 198,731 vehicles (NHTSA 19V-348, FCA campaign V53).
Looking for U0100 on a different make?
View U0100 across all makes →Frequently Asked Questions
What does U0100 mean on Chrysler?▼
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 Chrysler specifically, this code is documented across 1 model.
What causes U0100 on Chrysler vehicles?▼
Common causes on Chrysler: 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 Chrysler?▼
Repair costs vary widely depending on the root cause and specific Chrysler model.
Which Chrysler models have U0100 documented?▼
Au7o has documented U0100 on 1 Chrysler model: Pacifica.