DOCUMENTED DIAGNOSTIC CONTEXT
Diagnostic code articles — Page 40.
Understand what the recorded fault means, which findings change the diagnosis, and what the cited documentation can confirm. Each article states the system or vehicle scope it covers.
Some sources leave details unresolved. Those articles include a visible source note; a code match alone does not establish applicability to your vehicle.
Generic OBD-II
U0499
telematics positioning data fails protection validation
NetworkRead article
Generic OBD-II
U04A4
particulate sensor data fails counter and protection checks
NetworkRead article
Generic OBD-II
U04B1
battery monitor rolling counters fail on the LIN interface
NetworkRead article
Generic OBD-II
U0504
Aviator gearshift data faults with multiple door-latch warnings
NetworkRead article
Generic OBD-II
U0515
Remote-park data validity has an application-specific boundary
NetworkRead article
Generic OBD-II
U053B
radar rejects protected host-vehicle path information
NetworkRead article
Generic OBD-II
U053C
processor-2 data-group integrity failures
NetworkRead article
Generic OBD-II
U053D
video-processing messages arrive with invalid protection
NetworkRead article
Generic OBD-II
U0546
Invalid infotainment data reported by SAIC's brake controller
NetworkRead article
Generic OBD-II
U055A
Special-purpose module data must be judged against the actual upfitter configuration
NetworkRead article
Generic OBD-II
U0565
Gladiator rear-camera data without a picture fault
NetworkRead article
Generic OBD-II
U0566
automatic-braking message rolling counter fails at the brake controller
NetworkRead article
Generic OBD-II
U056B
Camera data arrives with invalid integrity or freshness
NetworkRead article
Generic OBD-II
U0585
grille shutter A initialization-status counter is invalid
NetworkRead article
Generic OBD-II
U0586
grille shutter B initialization-status data fails its counter check
NetworkRead article
Generic OBD-II
U0593
Hybrid drive-controller torque or gear messages fail integrity checks
NetworkRead article
Generic OBD-II
U0594
Ram eTorque data fault with an incompletely seated MGU connector
NetworkRead article
Generic OBD-II
U0599
DC/DC converter voltage and crank-status messages fail validation
NetworkRead article
Generic OBD-II
U059E
engine-out NOx sensor A data fails protection checks
NetworkRead article
Generic OBD-II
U059F
post-catalyst NOx sensor B information fails integrity checks
NetworkRead article
Generic OBD-II
U05A1
The upstream NOx sensor rejects invalid or late PCM information
NetworkRead article
Generic OBD-II
U05A2
Tailpipe NOx invalid-data faults require message context
NetworkRead article
Generic OBD-II
U05A8
third NOx sensor messages fail counter or checksum validation
NetworkRead article
Generic OBD-II
U05AA
Charge-air cooler pump messages fail the alive-counter check
NetworkRead article
Generic OBD-II
U0600
Digital oil-pressure communication needs a SENT-specific interpretation
NetworkRead article
Generic OBD-II
U0601
digital filter-pressure sensor SENT communication fails
NetworkRead article
Generic OBD-II
U0606
throttle sensor 1 SENT communication is invalid
NetworkRead article
Generic OBD-II
U0607
throttle sensor 2 sends unusable SENT information
NetworkRead article
Generic OBD-II
U0608
Throttle B uses a position channel named C in this Ford monitor
NetworkRead article
Generic OBD-II
U060F
the air-flow sensor loses particular LIN messages
NetworkRead article
Generic OBD-II
U0610
Mass-airflow sensor B communication timing failures
NetworkRead article
Generic OBD-II
U0611
Intake-air temperature sensor 1 communication faults
NetworkRead article
Generic OBD-II
U0612
Resolve the sensor-name mismatch before locating the communication fault
NetworkRead article
Generic OBD-II
U0613
Intake-air temperature sensor 2 and shared communication events
NetworkRead article
Generic OBD-II
U0615
Ram coolant-valve communication loss with connector corrosion
NetworkRead article
Generic OBD-II
U0617
coolant bypass valve C SENT data becomes stale
NetworkRead article
Generic OBD-II
U0618
Missing LIN response from coolant bypass valve D
NetworkRead article
Generic OBD-II
U061F
exhaust temperature sensor 1 loses valid SENT communication
NetworkRead article
Generic OBD-II
U0620
exhaust temperature sensor 2 SENT messages are invalid or stale
NetworkRead article
Generic OBD-II
U0623
the auxiliary water pump stops communicating on LIN
NetworkRead article
Generic OBD-II
U0625
fuel-rail pressure sensor communication stays low
NetworkRead article
Generic OBD-II
U062F
Coolant pump C missing its low-temperature-loop LIN response
NetworkRead article
Generic OBD-II
U0632
cooling fan 1 misses its LIN communication deadline
NetworkRead article
Generic OBD-II
U0633
cooling fan 2 fails to return its LIN response
NetworkRead article
Generic OBD-II
U063E
The exhaust heat-exchanger bypass actuator stops replying on LIN
NetworkRead article
Generic OBD-II
U063F
coolant flow valve SENT position stream fails protocol checks
NetworkRead article
Generic OBD-II
U0644
Wastegate position sensor A SENT communication failure
NetworkRead article
Generic OBD-II
U0645
Ram active air-dam communication and connector condition
NetworkRead article
Generic OBD-II
U064F
intake runner swirl-position SENT protocol failure
NetworkRead article
Generic OBD-II
U0650
exhaust pressure valve position feedback loses valid SENT updates
NetworkRead article
Generic OBD-II
U0651
high-pressure EGR position sensor A SENT communication fails
NetworkRead article
Generic OBD-II
U0653
low-pressure EGR position sensor C communication failure
NetworkRead article
Generic OBD-II
U0654
diesel intake throttle position SENT data becomes unusable
NetworkRead article
Generic OBD-II
U0656
variable-geometry turbo position feedback loses valid SENT data
NetworkRead article
Generic OBD-II
U0659
left-front temperature actuator response missing on LIN
NetworkRead article
Generic OBD-II
U065A
right-front climate actuator timeout with an applicability caveat
NetworkRead article
Generic OBD-II
U065D
A fresh-air duct communication fault on SKYACTIV-X
NetworkRead article
Generic OBD-II
U0665
Bank 2 fuel-rail pressure sensor SENT signal loss
NetworkRead article
Generic OBD-II
U0669
low-pressure EGR differential-pressure sensor loses SENT data
NetworkRead article
Generic OBD-II
U0670
fuel-temperature sensor A loses SENT pulse traffic
NetworkRead article
Generic OBD-II
U0671
sensor B fuel-temperature communication needs polarity confirmation
NetworkRead article
Generic OBD-II
U0672
Engine coolant pump LIN communication timeout
NetworkRead article
Generic OBD-II
U0674
Wastegate-position sensor B loses its SENT signal
NetworkRead article
Generic OBD-II
U067C
why the cooling-fan 3 LIN response is missing
NetworkRead article
Generic OBD-II
U0680
Barometric pressure sensor B communication events
NetworkRead article
Generic OBD-II
U0688
Throttle-position sensor G SENT communication failure
NetworkRead article
Generic OBD-II
U068A
Barometric pressure sensor C and source-specific communication labels
NetworkRead article
Generic OBD-II
U068E
SENT communication failure and an EGR sensor-label mismatch
NetworkRead article
Generic OBD-II
U0693
Humidity sensor SENT error reports
NetworkRead article
Generic OBD-II
U0696
when a downstream pressure sensor stops communicating
NetworkRead article
Generic OBD-II
U069A
exhaust-temperature sensor 3 message loss
NetworkRead article
Generic OBD-II
U069B
Exhaust-temperature sensor 4 SENT communication faults
NetworkRead article
Generic OBD-II
U3000
why the module and failure subtype matter
NetworkRead article
Generic OBD-II
U3001
2021 F-150 steering-assist loss after low-voltage starting
NetworkRead article
Generic OBD-II
U3002
missing VIN programming versus a VIN mismatch
NetworkRead article
Generic OBD-II
U3003
module supply voltage outside its allowed window
NetworkRead article
Generic OBD-II
U3004
The BCM is checking accessory-relay output voltage
NetworkRead article
Generic OBD-II
U3006
Brake-controller input power A undervoltage paths
NetworkRead article
Generic OBD-II
U3007
Brake-controller input power B and redundant-supply faults
NetworkRead article
Generic OBD-II
U3008
Ground-path A imbalance detected by the brake controller
NetworkRead article
Generic OBD-II
U3009
Ground-path B imbalance in the brake-control system
NetworkRead article
Generic OBD-II
U300A
Ram headlamp ignition-status faults: stored versus active
NetworkRead article
Generic OBD-II
U300D
Ford transfer-case ignition input and a self-test trap
NetworkRead article
Generic OBD-II
U300E
When local ignition power disagrees with the BCM's message
NetworkRead article
Generic OBD-II
U300F
Ford accessory-status comparison through the instrument cluster
NetworkRead article
Generic OBD-II
U3010
Ford start-status mismatch and why a starter replacement is premature
NetworkRead article
Generic OBD-II
U3011
Ford OFF-state comparison and residual powered circuits
NetworkRead article
Generic OBD-II
U3012
Ford startup brake warnings and a historical ABS communication case
NetworkRead article
Generic OBD-II
U3017
Ram eTorque controller-clock faults in the expanded BPCM update
NetworkRead article
Generic OBD-II
U3018
disagreement between two module power inputs
NetworkRead article
Generic OBD-II
U3019
GM brake-control B/C power correlation
NetworkRead article
Generic OBD-II
U3023
Power A and run/crank inputs disagree
NetworkRead article
Generic OBD-II
U3033
Grand Cherokee security-certificate faults and gateway updates
NetworkRead article
Generic OBD-II
U3035
Ford TRON authentication faults after module replacement
NetworkRead article
Generic OBD-II
U3501
GM control-module input A voltage low
NetworkRead article
Generic OBD-II
U3502
GM control-module input A voltage high
NetworkRead article
Generic OBD-II
U3505
GM control-module input B voltage low
NetworkRead article
Generic OBD-II
U3506
GM control-module input B voltage high
NetworkRead article
Generic OBD-II
U3509
GM control-module input C voltage low
NetworkRead article
Generic OBD-II
U350A
GM control-module input C voltage high
NetworkRead article
These are code references, not a list of confirmed faults on every vehicle. Read the source and applicability notes, then match the exact vehicle, year, engine and scan report.