DOCUMENTED DIAGNOSTIC CONTEXT
Diagnostic code articles — Page 38.
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
P3412
Cylinder-2 valve-control output stays high during activation
PowertrainRead article
Generic OBD-II
P3417
Cylinder-3 deactivation circuit open-path check
PowertrainRead article
Generic OBD-II
P3419
Cylinder-3 control circuit fails its off-state low check
PowertrainRead article
Generic OBD-II
P3420
Cylinder-3 deactivation control circuit high
PowertrainRead article
Generic OBD-II
P3425
Cylinder-4 deactivation circuit loses continuity
PowertrainRead article
Generic OBD-II
P3427
Cylinder-4 deactivation output is pulled to ground
PowertrainRead article
Generic OBD-II
P3428
Cylinder-4 deactivation driver reports a supply-side short
PowertrainRead article
Generic OBD-II
P3433
Cylinder-5 deactivation control has an open-path fault
PowertrainRead article
Generic OBD-II
P3435
Cylinder-5 valve-control circuit is pulled low
PowertrainRead article
Generic OBD-II
P3436
Cylinder-5 valve-control output resists the on command
PowertrainRead article
Generic OBD-II
P3441
Cylinder-6 deactivation output has an open-path indication
PowertrainRead article
Generic OBD-II
P3442
Ram cylinder-six deactivation and optional MDS software
PowertrainRead article
Generic OBD-II
P3443
Cylinder-6 deactivation circuit fails the low-state check
PowertrainRead article
Generic OBD-II
P3444
Cylinder-6 deactivation control is held toward power
PowertrainRead article
Generic OBD-II
P3449
Cylinder-7 deactivation control circuit appears open
PowertrainRead article
Generic OBD-II
P3451
Cylinder-7 deactivation output remains grounded
PowertrainRead article
Generic OBD-II
P3452
Cylinder-7 deactivation control short toward supply
PowertrainRead article
Generic OBD-II
P3457
Cylinder-8 valve-control circuit loses its electrical path
PowertrainRead article
Generic OBD-II
P3459
Cylinder-8 deactivation control remains low after release
PowertrainRead article
Generic OBD-II
P3460
Cylinder-8 deactivation output stays high when driven
PowertrainRead article
Generic OBD-II
P3498
Cylinder 1 may fail to return from deactivation
PowertrainRead article
Generic OBD-II
P3499
Cylinder-2 deactivation permits unwanted air pumping
PowertrainRead article
Generic OBD-II
P349A
Cylinder-3 half-engine operation fails its airflow performance check
PowertrainRead article
Generic OBD-II
P349B
Cylinder 4 valve-performance fault after deactivation ends
PowertrainRead article
Generic OBD-II
P349C
Cylinder-5 deactivation does not produce the expected air behavior
PowertrainRead article
Generic OBD-II
P349F
Cylinder-8 deactivation performance leaves an air-pumping error
PowertrainRead article
Generic OBD-II
U0001
The transmission controller reports a CAN bus-off state
NetworkRead article
Generic OBD-II
U0002
Ford ECM transmit CAN buffer remains overloaded
NetworkRead article
Generic OBD-II
U0010
Transit camera-module code after BCM replacement programming
NetworkRead article
Generic OBD-II
U0019
ProMaster CAN-B faults and the BCM configuration step
NetworkRead article
Generic OBD-II
U0028
GM truck communication faults during electrical-load events
NetworkRead article
Generic OBD-II
U0029
a global bus timeout is broader than one missing message
NetworkRead article
Generic OBD-II
U0037
Mustang GTD suspension warnings and VDM software
NetworkRead article
Generic OBD-II
U0073
the ECM detects repeated Bus A off events
NetworkRead article
Generic OBD-II
U0074
Bus B off events require channel-specific interpretation
NetworkRead article
Generic OBD-II
U0075
CAN 1 bus-off detected by the EOCM3 receiver
NetworkRead article
Generic OBD-II
U0076
GM identifies a powertrain sensor CAN bus-off fault
NetworkRead article
Generic OBD-II
U0077
CAN bus fault and the adaptive-cruise fallback in this module
NetworkRead article
Generic OBD-II
U0078
CAN 9 bus-off counted over a sliding sample window
NetworkRead article
Generic OBD-II
U0079
Mazda maps the bus-G code to CAN bus No.7
NetworkRead article
Generic OBD-II
U007A
Bus H has entered the CAN bus-off state
NetworkRead article
Generic OBD-II
U007B
A ten-second bus-off finding on Mazda's CAN No.4
NetworkRead article
Generic OBD-II
U007D
A Mazda bus fault on the diagnostic-connector path
NetworkRead article
Generic OBD-II
U007E
front-camera CAN 8 bus-off and its downstream effects
NetworkRead article
Generic OBD-II
U007F
FlexRay bus-off state in the object-control network
NetworkRead article
Generic OBD-II
U0080
TBM2.0H Ethernet startup delay and stored faults
NetworkRead article
Generic OBD-II
U0100
the brake controller misses expected engine messages
NetworkRead article
Generic OBD-II
U0101
TCM message deadlines differ within one ECM monitor
NetworkRead article
Generic OBD-II
U0102
Transfer-case message timeout after CAN communication is enabled
NetworkRead article
Generic OBD-II
U0103
gear-shift module response missing on LIN bus 2
NetworkRead article
Generic OBD-II
U0104
cruise-control messages stop reaching the ECM
NetworkRead article
Generic OBD-II
U0106
Engine and glow-plug controllers lose expected messages
NetworkRead article
Generic OBD-II
U0109
A fuel-pump communication code may use duty-cycle limits
NetworkRead article
Generic OBD-II
U010C
Turbo-control communication uses separate message timeouts
NetworkRead article
Generic OBD-II
U010E
reductant control module CAN messages exceed their timeouts
NetworkRead article
Generic OBD-II
U010F
The A/C module timeout is separate from a short reply failure
NetworkRead article
Generic OBD-II
U0110
Mazda PHEV no-READY condition with luggage-compartment corrosion
NetworkRead article
Generic OBD-II
U0111
Cherokee hybrid battery communication and coordinated software
NetworkRead article
Generic OBD-II
U0115
The local PCM link that limits Mazda transmission functions
NetworkRead article
Generic OBD-II
U0120
How Mazda times a lost starter-generator message
NetworkRead article
Generic OBD-II
U0121
the TCM loses ABS-controller messages
NetworkRead article
Generic OBD-II
U0122
A brake-controller communication fault can stop headlamp leveling
NetworkRead article
Generic OBD-II
U0125
missing inertial data rather than a generic transmission timeout
NetworkRead article
Generic OBD-II
U0126
Steering-angle module message is missing at the receiver
NetworkRead article
Generic OBD-II
U0127
A TPMS communication code stored by the restraint module
NetworkRead article
Generic OBD-II
U0128
The restraint module can lose parking-brake messages
NetworkRead article
Generic OBD-II
U0129
the ECM misses brake-system control messages
NetworkRead article
Generic OBD-II
U012A
Chassis-control module A messages stop arriving
NetworkRead article
Generic OBD-II
U012D
A missing generator response on the documented LIN channel
NetworkRead article
Generic OBD-II
U0131
a steering-controller message exceeds its deadline
NetworkRead article
Generic OBD-II
U0132
Missing or undersized suspension messages at the brake controller
NetworkRead article
Generic OBD-II
U0134
brake controller did not receive a usable rear-steer status message
NetworkRead article
Generic OBD-II
U0137
Ram trailer-brake communication behind a park-assist warning
NetworkRead article
Generic OBD-II
U0138
Ford AWD controller missing all-terrain module messages
NetworkRead article
Generic OBD-II
U0139
suspension-module messages have two different timeout windows
NetworkRead article
Generic OBD-II
U0140
body-controller messages have several timeout windows
NetworkRead article
Generic OBD-II
U0146
the brake controller loses the gateway status message
NetworkRead article
Generic OBD-II
U0151
restraint-module messages missing at different rates
NetworkRead article
Generic OBD-II
U0154
restraint controller times out waiting for occupant status
NetworkRead article
Generic OBD-II
U0155
cluster communication faults can include a configuration question
NetworkRead article
Generic OBD-II
U0156
2026 CX-5 cockpit communication faults and a revision limitation
NetworkRead article
Generic OBD-II
U0158
Grand Cherokee stored HUD fault after logistics mode
NetworkRead article
Generic OBD-II
U0159
parking-assist braking-request message is late
NetworkRead article
Generic OBD-II
U015C
Ram automated-driving communication and decode-byte evidence
NetworkRead article
Generic OBD-II
U0162
The repeated display-status failures behind Mazda's U0162
NetworkRead article
Generic OBD-II
U0163
F-150 HVAC reporting an APIM communication loss
NetworkRead article
Generic OBD-II
U0164
HVAC communication loss is checked after reset and network recovery
NetworkRead article
Generic OBD-II
U0167
Fiesta BCM losing the remote-function module
NetworkRead article
Generic OBD-II
U0168
S580 ignition-lock communication code stored in the starter alternator
NetworkRead article
Generic OBD-II
U016A
a Transit self-test code on vehicles built without a TCU
NetworkRead article
Generic OBD-II
U016B
Electric A/C compressor messages are missing
NetworkRead article
Generic OBD-II
U016C
Missing pump B feedback is different from an internal-error message
NetworkRead article
Generic OBD-II
U0180
A lighting-module timeout described in the SAIC BCM table
NetworkRead article
Generic OBD-II
U0182
The front-lighting module depends on Mazda's equipment variant
NetworkRead article
Generic OBD-II
U0184
Stored radio communication faults on 2016 RA3/RA4 units
NetworkRead article
Generic OBD-II
U0186
A six-second amplifier communication fault with a useful operating clue
NetworkRead article
Generic OBD-II
U0187
Mazda's disc-player communication diagnosis includes its USB path
NetworkRead article
Generic OBD-II
U0193
Fiesta display reporting missing audio-controller messages
NetworkRead article
Generic OBD-II
U0196
Flex rear entertainment communication and receiver agreement
NetworkRead article
Generic OBD-II
U0197
Hands-free module boot failure and communication diagnosis
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.