U0198 code meaning
Lost Communication With Telematic Control Module
What U0198 means
U0198 marks the telematic control module as silent; that unit holds the cellular modem for remote apps, emergency and assistance calls. Ford's APIM stores it on 2012-2018 Focus Electric, Fusion Energi and C-MAX Energi when the TCU hangs: SSM 46534 and 47198 report a drained battery, dead MyFord Mobile features and no modem ESN, cured by pulling the TCU fuse for five minutes and reprogramming. For the 2023 Super Duty, SSM 51578 treats U0198:87 in the BCM after a self-test as a false history entry to ignore if the MIL is off. Mazda SA-029/20 (Mazda3, CX-30) ties U0198:00 in the BCM to the emergency call unit; GM PIT5422 (Equinox, Terrain) traces it to water in connector X901. U0197 is the phone module, U0499 invalid data.
U0198 at a glance
- Check engine lightUsually not
- Emissions testNot an emissions code
- Limp modeNot expected
- Repair difficultyMedium
- Typical labor0.5 to 3 hours
- Clears after repairWhen cleared with a scanner
Symptoms of U0198
- Remote app, emergency or assistance call unavailable
- Battery drained overnight (Ford plug-in models)
- Network warning in the cluster, often with further U-codes
Common causes of U0198
- Most likelyTelematics unit hung or outdated software (Ford TCU reprogramming)
- PossibleWater or corrosion in a body harness connector (GM X901)
- PossibleLow-speed bus wire pinched or chafed in the roof or body
- Less likelyFalse history entry from a module self-test (Ford Super Duty)
- Less likelyTelematic control module faulty
Check the most likely causes first. Replacing parts by guesswork is the most expensive way to clear a code.
Parts involved
Telematics moduleCAN bus wiring
What each part of U0198 means
| U | Network system: communication between the control modules (CAN bus). |
| 0 | Generic code: it means the same on every make (SAE standard). |
| 98 | The exact fault in that area. |
What to do next
- Note U0198 and any other codes stored with it: several codes together often point to one cause.
- Check for loose connectors and damaged wiring around the parts the code names.
- Check open recalls for your car: some faults are fixed for free by the dealer. Enter your VIN.
- Clear the code only after the repair. If it comes back, the fault is still there.
Buying a used car? Scan it for stored codes before you pay. A recently cleared memory can hide a problem.
Questions about U0198
What does U0198 mean?
U0198 means "Lost Communication With Telematic Control Module". U0198 marks the telematic control module as silent; that unit holds the cellular modem for remote apps, emergency and assistance calls. It is a generic code, so it means the same on every make.
Is it safe to drive with U0198?
U0198 does not normally turn on the check engine light by itself. Watch for the symptoms above and have it checked soon.
Will U0198 fail an emissions test?
U0198 is not an emissions code, so on its own it usually does not fail an emissions test. Other stored codes or a lit check engine light still can.
How hard is U0198 to fix?
Difficulty: medium. A typical repair takes 0.5 to 3 hours of work. This is a job for a workshop.
Will U0198 clear itself after the repair?
Clear the code with a scanner after the repair. If the fault is fixed, it does not come back.