U065E

Code

Generic U — Network/User

Lost Communication With Ram Air Actuator

Brand: Generic

Type: U — Network/User

Views: UK: 17 EN: 30 RU: 25

AI status

Completed

ready

Completed 100%

Page language: EN

Causes

Open/short or chafed wiring between actuator and network/ECU
Corroded or loose connector at the actuator
Faulty ram air actuator (internal controller or motor)
Faulty power or ground to the actuator
CAN/LIN network fault, short to battery/ground, or missing termination
Faulty gateway/ECU or software mismatch after module replacement/update

Symptoms

Malfunction Indicator Lamp (MIL) or dash communication warning illuminated
Specific system warnings related to intake/ram air or reduced engine performance
Actuator does not move when commanded or moves erratically
Other modules report communication errors on scan tool
Possible limp-home mode or altered intake routing/noise

What to check

Read and record U065E plus any other stored network codes and freeze-frame data with a capable scan tool
Check for related codes in other modules (U0xxx family) to identify network-wide issues
Visually inspect actuator connector and wiring for corrosion, damage, or pins pushed out
Verify fuses and battery connections for circuits powering the actuator
With ignition ON, check for presence of battery voltage at actuator power terminal and a good chassis/ECU ground
Check CAN/LIN bus status on scan tool (bus off, error counters) and whether other modules are communicative

Signal parameters

Expected network messages from ram air actuator: periodic status and position messages (message ID varies by vehicle)
Typical bus voltage idle: CANH ≈ 2.5 V, CANL ≈ 2.5 V (differential ~0 V); when active differential pulses present
Network bitrate must match vehicle specification (commonly 125/250/500 kb/s)
Actuator feedback: commanded position vs actual position bytes; update rate typically 1–20 Hz depending on system
Power feed: battery voltage at actuator with ignition ON (approx. VBATT)
Actuator motor current draw when commanded (manufacturer-specific)

Diagnostic algorithm

Verify code: connect OEM-level or bidirectional scan tool, retrieve U065E plus related codes and freeze-frame data; record module responding and timestamp.
Attempt to command/actuate: use bi-directional control to request actuator status or move actuator while watching live data. Note response or lack of response.
Check network health: verify other modules respond. If multiple modules report comms faults, troubleshoot CAN/LIN bus power, ground, termination, and gateway before replacing actuator.
Visual inspection: inspect actuator connector, pins and harness for corrosion, bent pins, water intrusion, or damage. Repair or replace harness/connector as needed.
Power/ground tests: with connector disconnected, check for battery voltage on the power feed with ignition ON and a good ground return. Repair open or high-resistance connections.
Continuity and short tests: check continuity between actuator pins and the ECU/gateway connector; check for short to battery or ground on communication lines.
Electrical signal verification: using an oscilloscope or proper CAN/LIN tester, verify expected network messages at the actuator connector and correct voltage waveform/bitrate. Measure termination resistance across CANH-CANL.
Isolate actuator: disconnect actuator and observe whether network errors clear or other modules recover. If disconnecting actuator clears network faults, suspect actuator or local harness.
Replace suspected failed component: if wiring and network are good but actuator won’t respond, replace actuator module and retest. If issue persists and multiple modules unaffected, consider gateway or ECU replacement or software update.
Final check: clear codes, perform functional tests and a road test or system exercise to confirm the fault does not return.