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Jeep U0101

LOST COMMUNICATION WITH TCM U0140-00-LOST COMMUNICATION WITH BODY CONTROL MODULE (ESM) U0155-00-LOST COMMUNICATION WITH CLUSTER/CCN (ESM

DriveNot yet established by verified evidence. The diagnostic record lists safe-to-drive status as unknown.
ChargeNot yet established by verified evidence. The diagnostic record lists safe-to-charge status as unknown.
ServiceProfessional service is appropriate because the verified evidence concerns module communication and directs diagnostic evaluation of multiple LOC DTCs, battery health, and system voltage. The supplied record does not establish urgency or a specific repair.
Confidence95%

Quick answer

U0101 is a verified Jeep diagnostic trouble code for lost communication with the Transmission Control Module (TCM). In the supplied evidence, it also appears with Electronic Shift Module (ESM) communication faults including U0140-00 and U0155-00. The evidence supports professional diagnosis, but does not establish a specific failed part for every vehicle.

This page separates verified manufacturer/regulator evidence from supporting material. Unsupported causes, repairs or safety conclusions are not guessed.

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DTC Suzuki U0101 Short ExplanationMaxidot Jeep

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1. What does U0101 mean?

U0101 is a verified Jeep diagnostic trouble code for lost communication with the Transmission Control Module (TCM). In the supplied evidence, it also appears with Electronic Shift Module (ESM) communication faults including U0140-00 and U0155-00. The evidence supports professional diagnosis, but does not establish a specific failed part for every vehicle.

2. Technical explanation

The verified diagnostic title/meaning identifies U0101 as “Lost Communication With TCM.” A 2026 official manufacturer communication also documents an instrument-cluster message associated with ESM bus-message DTCs, including U0101-00, U0140-00, and U0155-00. An official 2025 manufacturer communication identifies U0101 among relevant loss-of-communication (LOC) codes and provides diagnostic direction when multiple LOC DTCs are present.

3. What system is affected?

Transmission Control Module (TCM) communication; Electronic Shift Module (ESM) bus-message communication is also referenced in the verified manufacturer communication.

4. How serious is this code?

Not yet established by verified evidence. The diagnostic record lists severity as unknown.

5. Symptoms you may notice

  • Malfunction Indicator Lamp (MIL) illumination is documented in official manufacturer communications for vehicles meeting the applicable bulletin conditions.
  • An instrument-cluster message is documented in an official manufacturer communication for DTCs specific to ESM bus messages.
  • Not yet established by verified evidence whether every vehicle with U0101 will have these symptoms.

6. Possible causes

  • If multiple modules report the same loss-of-communication condition, the official manufacturer communication states that the ESM is not the cause because it is not a gateway module.
  • For multiple LOC DTCs, the official manufacturer communication directs checking battery health and system voltage.
  • Not yet established by verified evidence whether a particular module, wiring connection, battery condition, or other component is the cause on an individual vehicle.

7. Can I still drive the vehicle?

Not yet established by verified evidence. The diagnostic record lists safe-to-drive status as unknown.

8. Can I charge the vehicle?

Not yet established by verified evidence. The diagnostic record lists safe-to-charge status as unknown.

9. What you can safely do

  • Record all stored DTCs and any instrument-cluster messages for the servicing dealer or qualified technician.
  • Arrange professional diagnosis, particularly if multiple loss-of-communication DTCs are present.
  • Do not attempt high-voltage-system repair based on this code.

10. Step-by-step troubleshooting

  1. A qualified technician can read all DTCs and determine whether multiple loss-of-communication DTCs are present.
  2. For multiple LOC DTCs, the official manufacturer communication directs checking battery health and system voltage.
  3. A qualified technician can determine whether multiple modules report the same LOC condition; the communication states that, in that circumstance, the ESM is not the cause.
  4. Not yet established by verified evidence what additional vehicle-specific diagnostic steps or repairs are required.

11. When to contact service

Professional service is appropriate because the verified evidence concerns module communication and directs diagnostic evaluation of multiple LOC DTCs, battery health, and system voltage. The supplied record does not establish urgency or a specific repair.

12. What the service center may check

  • Read and document all DTCs, including whether multiple LOC DTCs are present.
  • Check battery health and system voltage when multiple LOC DTCs are present.
  • Determine whether multiple modules report the same LOC condition.
  • Consider the official manufacturer communications identified below when confirming vehicle applicability and repair procedure.

13. Possible repair or resolution

  • Not yet established by verified evidence. The supplied evidence does not identify a confirmed repair or component replacement for every occurrence of U0101.

14. Affected vehicles

15. Related TSBs / service bulletins

  • NHTSA Manufacturer Communication 11014380: 21-016-25, published February 14, 2025. It lists U0101—Lost Communication With the TCM among DTCs associated with MIL illumination under its bulletin conditions. https://static.nhtsa.gov/odi/ffdd/tsbs/TSBS_RECEIVED_2025-2026.zip#nhtsa_id=11014380
  • NHTSA Manufacturer Communication 11014387: 21-016-25, published February 14, 2025. It lists U0101—Lost Communication With the TCM among DTCs associated with MIL illumination under its bulletin conditions. https://static.nhtsa.gov/odi/ffdd/tsbs/TSBS_RECEIVED_2025-2026.zip#nhtsa_id=11014387
  • NHTSA Manufacturer Communication 11021842: 9100641, published August 5, 2025. It identifies U0101 as a relevant code and states that, with multiple LOC DTCs, battery health and system voltage should be checked; it also states that the ESM is not the cause if multiple modules report the same LOC. https://static.nhtsa.gov/odi/ffdd/tsbs/TSBS_RECEIVED_2025-2026.zip#nhtsa_id=11021842
  • NHTSA Manufacturer Communication PDF 11027642: S2623000002, published January 9, 2026. It documents an instrument-cluster message with ESM bus-message DTCs including U0101-00, U0140-00, and U0155-00. https://static.nhtsa.gov/odi/tsbs/2026/MC-11027642-0001.pdf

16. Recall information

  • Not yet established by verified evidence. No recall information was supplied.

17. Official manufacturer information

Verified applicability is limited to U.S.-market Jeep Grand Cherokee model years 2022–2026 and Jeep Wagoneer model years 2022–2026, with overlapping duplicate applicability entries in the supplied data. Confirm the exact VIN, vehicle configuration, and bulletin eligibility with an authorized Jeep dealer. Verified sources are NHTSA-hosted manufacturer communications.

19. Frequently asked questions

What does U0101 mean?

Verified evidence identifies U0101 as Lost Communication With the Transmission Control Module (TCM).

Does U0101 prove that the TCM has failed?

No. The supplied verified evidence does not establish a failed TCM or any other specific component for every U0101 occurrence.

Can an ESM be blamed when several modules have loss-of-communication codes?

The official manufacturer communication states that if multiple modules report the same LOC, the ESM is not the cause because it is not a gateway module.

What is a verified diagnostic consideration when several LOC codes are present?

The official manufacturer communication directs checking battery health and system voltage when multiple LOC DTCs are present.

Is this code covered by a recall?

Not yet established by verified evidence. No recall information was supplied.

20. Sources & verification

ReferenceVerified
Jeep U0101: LOST COMMUNICATION WITH TCM U0140-00-LOST COMMUNICATION… | EV Diagnostics