U2515

Code

LAND ROVER U — Network/User

CAN bus — no communication from rear electronic module

Brand: LAND ROVER

Type: U — Network/User

Views: UK: 30 EN: 35 RU: 39

AI status

Completed

ready

Completed 100%

Page language: EN

Causes

Blown fuse or loss of power to the REM
Poor or open ground at the REM
Physical damage, corrosion or disconnected connector at the REM or CAN splice
Broken or shorted CAN_H / CAN_L wiring between REM and main CAN backbone
Missing or incorrect CAN termination (open or shorted termination resistor)
REM internal failure (hardware/software) or module bus-off condition

Symptoms

Loss of rear-specific functions (rear lights, wipers, tailgate, parking sensors, rear door locking) or inoperative rear convenience features
Instrument cluster/messages: warning or ‘Service Rear Module’ type messages
Unable to communicate with REM using diagnostic tool (no response)
Multiple network-related DTCs present on scan tool
Intermittent or permanent loss of functions related to the rear CAN network

What to check

Retrieve full freeze frame and all stored U-/B-/C-/P-codes with a capable scan tool
Check battery voltage (engine off and cranking) and charging system health
Inspect and check fuses and fusible links feeding the REM
Visually inspect REM connector, mating connector, and harness for corrosion, damage, or water intrusion
Measure supply voltage and ground continuity at the REM power/ground pins
Measure CAN_H and CAN_L single-ended voltages at the REM connector (key on, engine off) and check for differential activity

Signal parameters

CAN_H typical idle voltage: ~2.5 V (can rise to ~3.5 V during dominant bits)
CAN_L typical idle voltage: ~2.5 V (can drop to ~1.5 V during dominant bits)
Differential voltage during dominant bits: ~2.0 V (CAN_H > CAN_L)
Differential voltage during recessive: ~0 V (both ~2.5 V)
Bus termination resistance (across CAN_H to CAN_L): ~60 ohms (two 120 ohm terminators in parallel)
Supply voltage to REM: battery nominal ~12–14.5 V (depending on engine running)

Diagnostic algorithm

Connect a full-function scan tool and record all stored and pending codes across all modules; note any related network codes.
Verify battery voltage (>12.2 V recommended) and ensure good charging system. Recharge or replace if low.
Check fuses and power feeds to the REM; verify ignition-switched and constant supplies at the REM connector with a meter.
Verify solid ground(s) at the REM. Measure voltage drop on ground while exercising circuits if intermittent.
With ignition OFF, measure resistance between CAN_H and CAN_L at the REM connector — expect ~60 ohms. If open or much higher, suspect broken termination or open bus.
With ignition ON (key on, engine off), measure single-ended voltages on CAN_H and CAN_L at the REM connector and verify differential behavior while actuating other modules or using a CAN traffic generator.
Use a scope or CAN analyzer to check for normal bus traffic and for a dominant bus state or bus off condition. Identify if the bus is being held dominant by a shorted module or wiring.
Visually inspect and flex test wiring and connectors between the REM and nearest splice/junction; look for water ingress, chafing, or pin corrosion. Repair any damaged wiring or connectors.
If wiring and supply/ground are good but no communication, try disconnecting other modules on the same bus one at a time (if practical and safe) to identify a device pulling the bus down.
If the REM shows no power/ground or failed connector pins, repair the harness/connector and retest.
If all bus wiring, power and ground are confirmed good and the bus otherwise healthy but the REM does not respond, consider module replacement or reflashing. Reprogram/configure replacement REM per manufacturer procedures and clear codes.
After repair, clear all codes and verify correct operation of rear functions and that no related network DTCs return. Road test to confirm intermittent faults are resolved.

Likely causes

Fuse or supply/ground fault at the REM
Open or high-resistance CAN connection at REM harness connector or splice
CAN pair shorted to battery or ground at a nearby harness section
Failed REM or module in bus-off state
Incorrect or failed termination resistor (open or high resistance)

Fault status

⚠️ Status

No communication from Rear Electronic Module (REM) on CAN bus — module not responding. Check REM power, ground, CAN wiring/termination, and module state.

🟡 Repair difficulty: Medium

⏱️ Diagnostic time: 1.0-3.0 hours

Similar codes

Repair manuals

Manual library for LAND ROVER

413

Browse 413 LAND ROVER manuals: repair procedures, diagnostics, wiring diagrams, component locations, service data and Labor Times by year, model and trim.

LAND ROVER

Your experience will help others

+100 karma for a short comment :)

Was this AI description helpful?

Your feedback helps improve AI descriptions.

👍 Like 0 👎 Dislike 0

Send to email