U05A0

Code

Generic U — Network/User

Invalid Data Received from Evaporative Emission System Leak Detection Control Module

Brand: Generic

Type: U — Network/User

Views: UK: 26 EN: 42 RU: 22

AI status

Completed

ready

Completed 100%

Page language: EN

Causes

Faulty or intermittent CAN/LIN bus communication
Damaged wiring or poor connectors between modules
Faulty EVAP leak detection control module
Low battery voltage or intermittent power/ground to the module
Grounding issues or high resistance connections
Software mismatch, corrupted module firmware, or required calibration update

Symptoms

Malfunction Indicator Lamp (MIL) or warning lamp illuminated
EVAP system leak detection not available or incomplete readiness monitor
Communication errors reported on scan tool; module may be listed as not responding
Possible drivability unaffected but EVAP functions/errors persist
Intermittent or persistent stored U05A0 (communication/data) code

What to check

Connect a capable scan tool and confirm all stored codes and freeze frame data
Verify the EVAP LDCM ID appears on the network and attempt live data/communication
Check for other related U- and P-codes that indicate network or power issues
Measure battery voltage with key on and engine running (should be ~11–14.5 V)
Inspect connectors and wiring at the EVAP module for corrosion, bent pins, or damage
Perform wiggle test of harness while monitoring communication and DTCs

Signal parameters

Module supply voltage: nominal 11–14.5 V with key on/engine running
Ground: near 0 V; connector pin-to-chassis resistance should be very low (
CAN idle common-mode voltage: ≈2.5 V (CANH and CANL near 2.5 V) with differential inactive
CAN active differential: CANH ≈3.5 V, CANL ≈1.5 V during dominant bits (verify with oscilloscope)
LIN or single-wire serial (if used): idle voltage near battery/2 or specified by manufacturer — observe waveform for corruption
Termination resistance: approx. 60 Ω across CANH–CANL (two 120 Ω terminators in parallel)

Diagnostic algorithm

Retrieve and record all DTCs and freeze frame data with a scan tool; note whether the EVAP LDCM module is listed and responsive.
Attempt to communicate directly with the EVAP LDCM using a factory-level scan tool; confirm supported PIDs and ability to read live data.
Visually inspect the EVAP module connector and wiring for damage, corrosion, bent pins, water intrusion, or evidence of shorting.
With key on (engine off), measure module supply voltage and ground at the connector; confirm proper battery voltage and good ground continuity.
Measure CANH/CANL (or LIN) voltages at the module connector with a DMM; if suspect, capture waveform with an oscilloscope while exercising the bus (key cycles, module communication).
Check termination resistor across CANH–CANL. If out of range, trace and repair missing or extra termination devices or shorts.
Perform wiring continuity and resistance checks between the EVAP module and the PCM/ECU backbone; look for opens, shorts to power or ground, or high resistance.
If wiring and power/grounds are good, verify software/calibration levels and reflash or update modules per manufacturer procedures; ensure replacement modules are correctly programmed.
Clear codes, then perform communication checks and a drive/monitor cycle to confirm the fault does not return. If intermittent, stress-test harness routing and connectors.
Replace the EVAP leak detection control module only after confirming wiring, power, grounds, and software are correct.

Likely causes

Open, short, or high-resistance in CAN/LIN wiring to EVAP LDCM
Corroded or loose connector pins at the EVAP module
Failed EVAP leak detection control module electronics
Missing or weak ground/power supply to module (voltage below ~11 V during key on)
Incorrect module programming or incompatible replacement module

Fault status

⚠️ Status

Controller received invalid or corrupted data from the evaporative emission system leak detection control module. Communication/data integrity fault between modules; EVAP LDCM not providing expected/valid messages.

🟡 Repair difficulty: Medium

⏱️ Diagnostic time: 1.0-3.0 hours