OBD2 · Network
U01xx codes: lost communication — powertrain, chassis and body modules
94 codes in this range, all generic — the same meaning on every make. Codes stored when one module stops receiving messages from another — the engine or transmission computer, ABS, airbags, body control, instrument cluster or dozens of others. The code names the module that went silent, not the one that stored it.
What usually causes codes in this area
- Low battery voltage or a poor battery connection
- A blown fuse or failed relay feeding the silent module
- Damaged network wiring or a corroded connector
- A failed module
Can you keep driving?
It depends on which module is missing: the engine, transmission, ABS or airbag module — have it checked straight away; comfort modules can wait. A weak battery can set many of these codes at once, so check it first.
All U01xx codes
| Code | Meaning |
|---|---|
| U0100 | Lost Communication With ECM/PCM "A" |
| U0101 | Lost Communication With TCM |
| U0102 | Lost Communication With Transfer Case Control Module |
| U0103 | Lost Communication With Gear Shift Module |
| U0104 | Lost Communication With Cruise Control Module |
| U0105 | Lost Communication With Fuel Injector Control Module |
| U0106 | Lost Communication With Glow Plug Control Module |
| U0107 | Lost Communication With Throttle Actuator Control Module |
| U0108 | Lost Communication With Alternative Fuel Control Module |
| U0109 | Lost Communication With Fuel Pump Control Module |
| U0110 | Lost Communication With Drive Motor Control Module |
| U0111 | Lost Communication With Battery Energy Control Module "A" |
| U0112 | Lost Communication With Battery Energy Control Module "B" |
| U0113 | Lost Communication With Emissions Critical Control Information |
| U0114 | Lost Communication With Four-Wheel Drive Clutch Control Module |
| U0115 | Lost Communication With ECM/PCM "B" |
| U0116 | Lost Communication With Coolant Temperature Control Module |
| U0117 | Lost Communication With Particulate Filter Control Module |
| U0118 | Lost Communication With Fuel Additive Control Module |
| U0119 | Lost Communication With Fuel Cell Control Module |
| U0120 | Lost Communication With Starter/Generator Control Module |
| U0121 | Lost Communication With Anti-Lock Brake System (ABS) Control Module |
| U0122 | Lost Communication With Vehicle Dynamics Control Module |
| U0123 | Lost Communication With Yaw Rate Sensor Module |
| U0124 | Lost Communication With Lateral Acceleration Sensor Module |
| U0125 | Lost Communication With Multi-Axis Acceleration Sensor Module |
| U0126 | Lost Communication With Steering Angle Sensor Module |
| U0127 | Lost Communication With Tire Pressure Monitor Module |
| U0128 | Lost Communication With Park Brake Control Module |
| U0129 | Lost Communication With Brake System Control Module |
| U0130 | Lost Communication With Steering Effort Control Module |
| U0131 | Lost Communication With Power Steering Control Module |
| U0132 | Lost Communication With Ride Level Control Module |
| U0137 | Lost Communication With Trailer Brake Control Module |
| U0140 | Lost Communication With Body Control Module |
| U0141 | Lost Communication With Body Control Module "A" |
| U0142 | Lost Communication With Body Control Module "B" |
| U0143 | Lost Communication With Body Control Module "C" |
| U0144 | Lost Communication With Body Control Module "D" |
| U0145 | Lost Communication With Body Control Module "E" |
| U0146 | Lost Communication With Gateway "A" |
| U0147 | Lost Communication With Gateway "B" |
| U0148 | Lost Communication With Gateway "C" |
| U0149 | Lost Communication With Gateway "D" |
| U0150 | Lost Communication With Gateway "E" |
| U0151 | Lost Communication With Restraints Control Module |
| U0152 | Lost Communication With Side Restraints Control Module (Left) |
| U0153 | Lost Communication With Side Restraints Control Module (Right) |
| U0154 | Lost Communication With Restraints Occupant Sensing Control Module |
| U0155 | Lost Communication With Instrument Panel Cluster (IPC) Control Module |
| U0156 | Lost Communication With Information Center "A" |
| U0157 | Lost Communication With Information Center "B" |
| U0158 | Lost Communication With Head Up Display |
| U0159 | Lost Communication With Parking Assist Control Module "A" |
| U0160 | Lost Communication With Audible Alert Control Module |
| U0161 | Lost Communication With Compass Module |
| U0162 | Lost Communication With Navigation Display Module |
| U0163 | Lost Communication With Navigation Control Module |
| U0164 | Lost Communication With HVAC Control Module |
| U0165 | Lost Communication With HVAC Control Module (Rear) |
| U0166 | Lost Communication With Auxiliary Heater Control Module |
| U0167 | Lost Communication With Vehicle Immobilizer Control Module |
| U0168 | Lost Communication With Vehicle Security Control Module |
| U0169 | Lost Communication With Sunroof Control Module |
| U0170 | Lost Communication With Restraints System Sensor "A" |
| U0171 | Lost Communication With Restraints System Sensor "B" |
| U0172 | Lost Communication With Restraints System Sensor "C" |
| U0173 | Lost Communication With Restraints System Sensor "D" |
| U0174 | Lost Communication With Restraints System Sensor "E" |
| U0175 | Lost Communication With Restraints System Sensor "F" |
| U0176 | Lost Communication With Restraints System Sensor "G" |
| U0177 | Lost Communication With Restraints System Sensor "H" |
| U0178 | Lost Communication With Restraints System Sensor "I" |
| U0179 | Lost Communication With Restraints System Sensor "J" |
| U0180 | Lost Communication With Automatic Lighting Control Module |
| U0181 | Lost Communication With Headlamp Leveling Control Module |
| U0182 | Lost Communication With Lighting Control Module (Front) |
| U0183 | Lost Communication With Lighting Control Module (Rear) |
| U0184 | Lost Communication With Radio |
| U0185 | Lost Communication With Antenna Control Module |
| U0186 | Lost Communication With Audio Amplifier |
| U0187 | Lost Communication With Digital Disc Player/Changer Module "A" |
| U0188 | Lost Communication With Digital Disc Player/Changer Module "B" |
| U0189 | Lost Communication With Digital Disc Player/Changer Module "C" |
| U0190 | Lost Communication With Digital Disc Player/Changer Module "D" |
| U0191 | Lost Communication With Television |
| U0192 | Lost Communication With Personal Computer |
| U0193 | Lost Communication With Digital Audio Control Module "A" |
| U0194 | Lost Communication With Digital Audio Control Module "B" |
| U0195 | Lost Communication With Subscription Entertainment Receiver Module |
| U0196 | Lost Communication With Rear Seat Entertainment Control Module |
| U0197 | Lost Communication With Telephone Control Module |
| U0198 | Lost Communication With Telematic Control Module |
| U0199 | Lost Communication With Door Control Module "A" |
Read the codes from your own car
Plug an inexpensive Bluetooth LE or Wi-Fi OBD2 adapter into the port under the dashboard, and Brimly on your iPhone reads the stored, pending and permanent codes, explains each one offline and clears them once the fault is fixed. OBD diagnostics are part of Brimly Forever, a one-time purchase.
Requires iOS 18.1 or later. Free to download, with optional in-app purchases.