Telematics Control Unit

TCU DTC Database

Complete diagnostic reference for JLR Telematics, SOS Emergency, and InControl systems. Search and filter through all TCU-related diagnostic trouble codes.

25 DTC Codes All JLR Models InControl & SOS
Search Codes Back to RFA Codes

TCU Programming - Paid Addon Service

Important: If key programming fails due to a damaged or misconfigured TCU, you will need our special TCU addon service. This is NOT included in any Lock50 package and requires remote assistance from the Lock50 team.

TCU programming uses special functions that are not for public release. Even C+ tier users require this paid service to resolve TCU-related issues.

£300 + VAT
for TCU diagnosis & repair
Remote Login Required
Special Functions
Contact us to arrange remote assistance → Contact Us

What is TCU?

The Telematics Control Unit manages connected services including emergency SOS calls, InControl remote features, and vehicle tracking.

Emergency Call System
InControl App Features
GPS & Vehicle Tracking
WiFi Hotspot
NAV
Understanding TCU

What is the Telematics Control Unit?

The central hub for all wireless communication and connectivity features in modern JLR vehicles

The Telematics Control Unit (TCU) is a critical electronic control module in modern Jaguar Land Rover vehicles that serves as the central hub for all wireless communication and connectivity features.

Located typically behind the dashboard or in the roof console area, the TCU integrates cellular (3G/4G/LTE), GPS, and Bluetooth technologies to enable a wide range of connected vehicle services. It acts as the vehicle's "smartphone," constantly communicating with JLR's backend servers and the owner's mobile device.

The TCU contains an internal, non-serviceable backup battery that maintains emergency call functionality even if the main 12V vehicle battery is disconnected. This is a critical safety feature mandated by eCall regulations in many markets.

Without a Functioning TCU

Your JLR vehicle will lose access to InControl Remote services, emergency call capability, navigation updates, WiFi hotspot, and over-the-air updates. While the vehicle will still drive normally, you'll see "SOS System Inactive" or "SOS Limited Functionality" warnings.

Emergency Call (eCall)

Automatically contacts emergency services in a collision, transmitting location and crash data.

4G/LTE Connectivity

Provides WiFi hotspot functionality and enables over-the-air software updates.

GPS Tracking

Real-time vehicle location for InControl Remote, navigation, and stolen vehicle tracking.

Remote Control

Remote locking/unlocking, climate control, and vehicle status via smartphone app.

Security Services

Remote immobilization, geofencing alerts, and intrusion notifications.

Concierge Services

Access to JLR's premium assistance via the SOS/bCall buttons.

Visual Reference

What Do These Modules Look Like?

Visual identification guide for TCU, RFA, and BCM modules found in Jaguar Land Rover vehicles

TCU Module

Telematics Control Unit

TCU Telematics Control Unit Module JLR

Cellular & GPS: Provides 3G/4G/LTE connectivity

InControl Services: Remote features and tracking

Location: Behind dashboard or roof console

SOS Function: Emergency call capability

RFA Module

Remote Function Actuator

RFA JLR Remote Function Actuator Module

Keyless entry and remote functions

Location: Behind dashboard or trunk

RF: 315/433 MHz & UWB

BCM Module

Body Control Module

BCM Body Control Module JLR

Central locking & body electronics

Communicates with RFA

Location: Under dashboard or engine bay

Pro Tip: Module Identification

Always verify the module part number before ordering replacements. Use diagnostic tools like Lock50 or JLR SDD to read module information via OBD-II port. Each module has a unique part number printed on its label that corresponds to specific vehicle models and production years. For TCU modules, check generation (Gen 1-4) to ensure compatibility with your vehicle's cellular network technology.

Part Numbers & Market Data

TCU Specific Part Numbers

When searching on eBay or parts catalogs, you will find two types of numbers: Engineering/Assembly Numbers (found on the sticker) and Service Part Numbers (used for ordering).

1. The "Legacy" 3G Units

Now being Upgraded

Due to the "3G Sunset," many owners are replacing these. They are often made by LG or Harman.

Engineering/Assembly Numbers
DPLA-70718-CAA
J8A2-70718-CAA
Service Part Numbers
LR089861
LR091256
Common Use:

Range Rover L405 (early), Sport L494, Discovery 5

2. The Modern 4G/LTE Units

Pivi Pro Era

These support Software-Over-The-Air (SOTA) updates and are critical for the Pivi Pro system.

Engineering/Assembly Numbers
L8B2-70718-AY
J9C3-70712-AY
Service Part Numbers
LR131948
T2R33785 (Jaguar)
Common Use:

Defender (L663), New Range Rover (L460), Velar

3. The Next-Gen 5G Units

2024+

Newer models (2024MY+) use an updated architecture to support higher data throughput for autonomous driving features and faster infotainment.

Common Suffixes
N8B2 P8B2

Understanding Part Numbers

Engineering Numbers are found on the physical module sticker and contain the original manufacturer part number. Service Numbers are the ordering codes used by dealers and parts suppliers. Always verify both numbers match your vehicle's requirements before purchasing replacement units.

Troubleshooting & Technical Deep Dive

Critical Component: Internal Battery

Often, a "TCU Error" on the dashboard is just a dead internal battery rather than the whole module.

Before Replacing the Entire TCU...

Before spending £200–£500 on a replacement TCU module, check if it's just the internal backup battery that has died. Many "TCU Error" messages are caused by a simple battery failure.

Part Number LR089861
Jaguar Equivalent T2R23864
eBay Price £20–£40 ($25–$50)

Pivi Pro Era (2020–2026) TCU Complexity

For the Pivi Pro era, the TCU is much more complex than previous versions. It is no longer just a "modem"; it is a high-speed gateway (part of the EVA 2.0 architecture) that is hardware-locked to specific global regions and service types.

The Sticker "Color Coding" System

When looking at the sticker on a JLR TCU, the colored markers (often dots or bars) or the prominent label color indicate the Market Configuration and Network Frequency.

RED Sticker / Marker

NAS - North American Specification
  • Frequency: North American LTE bands (AT&T/T-Mobile/Verizon roaming)
  • Emergency: Hardcoded for 911 (FCC compliance)
  • The Trap: Will not provide data services if installed in a European or Chinese vehicle

YELLOW Sticker / Marker

ROW - Rest of World / UK / Europe
  • Frequency: GSM/LTE bands compatible with European carriers
  • Emergency: Hardcoded for eCall (112/999)
  • Best Choice: For UK, Europe, and Australia

BLUE / GREEN Marker

China (PRC) / Japan Specific
  • Frequency: China-specific LTE bands
  • Software: Different firmware for China regulations
  • Warning: Almost impossible to use for App outside China

WHITE / NO MARKER

Universal / Service Replacement
  • Base Unit: Usually for testing purposes
  • Requirement: Must be "provisioned" by the dealer

Pivi Pro (EVA 2.0) TCU Part Numbers

Pivi Pro units are almost exclusively manufactured by LG or Harman. They utilize an internal eSIM.

Region Engineering Number (On Sticker) Service Part Number (To Order) Notes
USA / Canada (NAS) L8B2-70718-AF / M8B2-70718-AB LR144040 / LR161533 4G LTE High Band
UK / Europe (ROW) L8B2-70718-AY / M8B2-70718-AY LR131948 / LR154567 4G LTE with eCall
China L8B2-70718-AC LR131949 Specific for Chinese Firewall
Global 5G (2024+) P8B2-70718-BA LR182344 Newest EVA 2.1 Architecture

Pivi Pro TCU Types: The "L8B2" & "M8B2" Family

In the Pivi Pro era, the TCU is much more than a modem—it is the Master Connectivity Module.

Generation Engineering Number Sticker Color Years Connectivity
Pivi Pro Gen 1 L8B2-70718-AF NAS/Red 2020-2022 4G LTE
Pivi Pro Gen 1 L8B2-70718-AY ROW/Yellow 2020-2022 4G LTE
Pivi Pro Gen 2 M8B2-70718-AB NAS/Red 2023-2024 4G LTE (Faster)
Pivi Pro Gen 2 M8B2-70718-AY ROW/Yellow 2023-2024 4G LTE (Faster)
Next-Gen 5G P8B2-70718-BA Purple 2025-2026 5G Hub

The "Lock50" Reality Check

Since you are using Lock50 HW04, here is what you need to know:

"The App is Dead"

Because the eSIM ID inside the used TCU is still registered to the donor car's VIN in the JLR Global Database, the client cannot "Add Vehicle" in the app. The server will see a mismatch and block the link.

No Remote Climate/Start

Since these features require the App to talk to the Cloud, and the Cloud won't talk to a "mismatched" TCU, the client loses Remote Start/Climate functionality.

The "Workaround" Myth

There is currently no public tool (including Lock50) that can reliably "re-virginize" the eSIM registration on the JLR Cloud side. The only way to get the app back is a Brand New (Virgin) TCU from JLR.

Summary of Part Counts (2010–2026)

Across all JLR models (Range Rover, Defender, Evoque, Jaguar F-Pace, etc.)

12–15
Distinct Hardware Variants
3G
Legacy Units
4G
Pivi Pro Era
5G
Next-Gen (2024+)

The Comprehensive Part Number & Type List

These are the physical Engineering Numbers you will see on eBay/Salvage stickers

Generation Sticker Color Region Engineering Number Service Part #
Pivi Pro 4G (Early) Yellow UK/Europe/ROW L8B2-70718-AY LR131948
Pivi Pro 4G (Early) Red North America L8B2-70718-AF LR144040
Pivi Pro 4G (Mid) Yellow UK/Europe/ROW M8B2-70718-AY LR154567
Pivi Pro 4G (Mid) Red North America M8B2-70718-AB LR161533
Pivi Pro 4G (High) Blue/Purple China/PRC L8B2-70718-AC LR131949
Next-Gen 5G Various Global P8B2-70718-BA LR182344

The Sticker "Cheat Sheet"

R

RED Sticker

High-band LTE
  • High-band LTE (B2/B4)
  • Hard-coded to dial 911
  • If used in UK: often shows "No Service"
  • Won't connect to emergency services abroad
Y

YELLOW Sticker

Mid-band LTE
  • Mid-band LTE (B1/B3/B7/B20)
  • Hard-coded for eCall (999/112)
  • Standard for UK and Europe
  • Best choice for ROW markets
W

WHITE Sticker

Service Exchange
  • Often "Service Exchange" units
  • Usually Virgin (not locked to VIN)
  • "Gold Mine" on eBay!
  • App will work with these

Lock50 HW04 Capability: The "Hard Truth"

You are 100% correct on the mechanics of how this tool works. Here is the technical flow:

1. Sync/Adaptation

Lock50 performs a seed-key calculation to allow the used TCU to talk to the Gateway (GWM) and BCM.

2. The Result

The car starts. The SOS light goes out. The infotainment (Pivi) shows a signal bar.

3. The VIN Conflict

Lock50 cannot change the ICCID (SIM ID) or the EID (eSIM identity) inside the TCU's secure enclave.

4. The App Failure

Because the JLR Cloud (InControl) checks the EID against the VIN, the server refuses the handshake. Client is locked out of the App forever on that module.

Key Takeaway

The App is Dead on used TCUs. Since the eSIM ID is still registered to the donor car's VIN in the JLR Global Database, the client cannot "Add Vehicle" in the app. The server will see a mismatch and block the link. Only a Brand New (Virgin) TCU from JLR will restore App functionality.

Diagnostic "Red Flags"

Internal Battery

LR089861
Battery Age Critical

If the sticker date is older than 3 years, the internal battery is likely dead.

Pro Tip: A dead battery in a "Good" used TCU will still trigger a dash error. Don't discard a TCU without checking this first!

Component Protection

2023+ Models (EVA 2.1)
Protection Level Enhanced

2023+ models have much stricter component protection than earlier generations.

Lock50 HW04 is currently the most reliable way to bypass this, but it still won't fix the App/Cloud issue.

Summary of TCU Quantities (2010–2026)

4
Main Hardware
Architectures
3
Primary Regions
(NAS, ROW, China)
18–22
Unique Engineering
Numbers
EVA 2.1
2023+ Models
Enhanced Security
UK/Europe/ROW
North America (NAS)
China/PRC
Service Exchange (Virgin)
Hardware Reference

TCU Generations & Part Numbers

Complete reference for all JLR Telematics Control Unit versions from 2012 to present

G1

TCU Gen 1

2012-2015
3G UMTS

Part Numbers

FX73-14G370-xx JX73-14G370-xx

Affected Models

Range Rover L405 (13-15MY) Range Rover Sport L494 (14-15MY) Discovery 4 (14-15MY)

Notes: First generation telematics with basic connectivity

G2

TCU Gen 2

2015-2017
3G/4G LTE

Part Numbers

HK83-14G370-xx JK83-14G370-xx

Affected Models

Range Rover L405 (15-17MY) Range Rover Sport L494 (15-17MY) Discovery 5 L462 (17MY) Evoque L538 (15-17MY) Discovery Sport L550 (15-17MY)

Notes: Common water ingress issues, internal backup battery failures

G3

TCU Gen 3

2017-2020
4G LTE Cat-4

Part Numbers

LR110668 LR111537 LR111916

Affected Models

Range Rover L405 (18-20MY) Range Rover Sport L494 (18-20MY) Range Rover Velar L560 (18-20MY) Discovery 5 L462 (18-20MY) Evoque L538 (19-20MY) Discovery Sport L550 (19-20MY)

Notes: Improved reliability, better backup battery management (U2109-09 common on new vehicles)

G4

TCU Gen 4

2020-2023
4G LTE Cat-4/6

Part Numbers

L8B2 M8B2 LR131948 LR136646 LR140282

Affected Models

Range Rover L405 (20-23MY) Range Rover Sport L494 (20-23MY) Defender L663 (20+MY) Range Rover Velar L560 (20-23MY) Discovery 5 L462 (20-23MY) Evoque L551 (20+MY)

Notes: Pivi Pro (EVA 2.0) platform - Enhanced connectivity with improved antenna integration

G5

TCU Gen 5

2024-2026
5G High-Speed

Part Numbers

N8B2 P8B2 LR180000+

Affected Models

New Range Rover L460 (24+MY) New Range Rover Sport L461 (24+MY) Defender L663 (24+MY) Range Rover Velar L560 (24+MY) Evoque L551 (24+MY)

Notes: Pivi Pro (EVA 2.1) platform - 5G high-speed connectivity with advanced V2X capabilities

JLR TCU Eras - Complete Reference

Era Years Connectivity Primary System Part Number Prefixes
Era 1 2010–2015 2G/3G IAM 2.1 / InControl CPLA, DPLA, AW93
Era 2 2016–2019 3G/LTE Touch Pro GPLA, HK83, J8A2
Era 3 2020–2023 4G LTE (Cat 4/6) Pivi Pro (EVA 2.0) L8B2, M8B2, LR131948
Era 4 2024–2026 5G (High-Speed) Pivi Pro (EVA 2.1) N8B2, P8B2, LR180000+
Troubleshooting

Common TCU Issues & Fixes

Quick reference for the most frequently encountered TCU problems and their solutions

Internal Backup Battery Failure

Related DTC U2109-09
Fix

Requires TCU replacement - battery not serviceable. Run vehicle for 60 minutes to charge on new install.

Water Ingress / Corrosion

Related DTCs
B1179-04 U0001-87
Fix

Locate and repair water source before TCU replacement. Check roof drains and antenna seals.

Parasitic Battery Drain

Related DTCs
B117C-04 P0560-04
Fix

TCU not sleeping properly. Check for internal short (8+ amps draw). Replace TCU if excessive.

No Cellular Signal

Related DTC B1177-04
Fix

Check antenna connections, verify in good signal area, may require TCU replacement.

SOS System Limited Functionality

Related DTCs Multiple DTCs
Fix

Check crash sensor circuit, SOS button wiring, microphone/speaker circuits, and TCU power supply.

Service Reference

Important Service Notes

Critical information for technicians working with JLR Telematics Control Units

Programming Required

All replacement TCUs must be programmed and configured with vehicle VIN using JLR SDD/Pathfinder diagnostic equipment.

Backup Battery Charging

After TCU replacement, vehicle must be driven or kept with ignition on for 60 minutes to fully charge internal backup battery.

Water Ingress Check

Always check for water damage before replacing TCU - fix root cause first to prevent repeat failures.

Antenna Verification

Verify GPS and cellular antenna connections are secure and undamaged during TCU diagnosis.

No Substitutes

TCUs are VIN-locked and must be genuine JLR parts - aftermarket units will not function.

Subscription Activation

InControl services may require reactivation after TCU replacement through JLR customer portal.

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TCU DTC Code Database

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TCU Programming - Paid Addon

If key programming fails due to damaged or misconfigured TCU, you need our special TCU addon service. NOT included in any Lock50 package.

Special functions not for public release - even C+ tier users need this paid service.

£300 + VAT
for TCU repair
Contact to arrange →

Need Help with TCU Issues?

Lock50 HW04 provides comprehensive solutions for JLR telematics, communication faults, and advanced module diagnostics.

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