P CODE FAMILY

Powertrain code references — Page 84.

Engine, transmission and powertrain diagnostic references. Exact vehicle and module context still matters.

Generic OBD-II

P281D

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.

why solenoid H circuit-low can also mean an open circuit

solenoid H voltage-high diagnosis depends on valve mapping

Pressure Control Solenoid J

a documented park-lock valve stuck-off monitor

how a park-lock valve is diagnosed hydraulically stuck on

Pressure Control Solenoid J Electrical

Pressure Control Solenoid J Intermittent

T93 default-disable valve open-circuit detection

Pressure Control Solenoid J Control Circuit Range/Performance

solenoid J circuit-low and the T87a open-circuit exception

what solenoid J circuit-high actually identifies

Pressure Control Solenoid K

Selector pilot stuck-off is distinguished from a selector spool fault

Selector pilot stuck-on needs both wrong-route movement and a failed profile

Pressure Control Solenoid K Electrical

Pressure Control Solenoid K Intermittent

Selector pilot open-load is an off-state electrical check

Pressure Control Solenoid K Control Circuit Range/Performance

Selector pilot circuit low uses driver evidence, not rod movement

Selector pilot high can originate in a shutdown cross-output test

Shift Fork A Position Circuit

Rod-one plausibility is checked against speed evidence and alternate actuation

Rod-one circuit low includes missing pulses or an undersized duty cycle

Rod-one circuit high can be a missing-pulse or duty-cycle fault

Rod-one intermittent code checks digital frequency, not just dropouts

Shift Fork B Position Circuit

Rod-two consistency uses independent gear evidence before blaming position

Rod-two electrical low is about pulse behavior, not fork travel

Rod-two high requires pulse-loss or excessive-duty evidence

Rod-two intermittent feedback is monitored through its frequency

Shift Fork C Position Circuit

Rod-three consistency is tied to the even-clutch speed references

Rod-three circuit low must be read with its reference-supply status

Rod-three high is a waveform-quality fault on the VREF2 group

Rod-three intermittent diagnosis evaluates signal timing

Shift Fork D Position Circuit

Rod-four plausibility depends on learned position and even-side speed checks

Rod-four circuit low can mean missing transitions or low duty

Rod-four circuit high has two distinct digital-signal routes

Rod-four intermittent feedback is a frequency-window check

Shift Fork A Position Sensor Incorrect Neutral Position Indicated

Shift Fork B Position Sensor Incorrect Neutral Position Indicated

Shift Fork C Position Sensor Incorrect Neutral Position Indicated

Shift Fork D Position Sensor Incorrect Neutral Position Indicated

Shift Fork A Stuck

Shift Fork B Stuck

Shift Fork C Stuck

Shift Fork D Stuck

Rod-one drift can be detected directly or through repeated correction

Repeated rod-two corrections can explain an unrequested-movement code

Rod-three drift uses even-side gear evidence and correction history

Rod-four unrequested movement can be a persistent control burden

Shift Fork Position Sensor A/B Correlation

Shift Fork Position Sensor C/D Correlation

Clutch-one pressure discharge performance means pressure below the model here

Clutch-two low pressure must be compared with what the model expects

Clutch-one charge performance includes excess pressure near the hold state

Clutch-two pressure charge performance depends on its control state

Clutch A Pressure Engagement Performance/Too Low

Clutch B Pressure Engagement Performance/Too Low

Clutch A Pressure Disengagement Performance/Too Low

Clutch B Pressure Disengagement Performance/Too Low

Shift Fork A Actuator Circuit/Open

Shift Fork A Actuator Performance

Shift Fork A Actuator Circuit Low

Shift Fork A Actuator Circuit High

Shift Fork B Actuator Circuit/Open

Shift Fork B Actuator Performance

Shift Fork B Actuator Circuit Low

Shift Fork B Actuator Circuit High

Shift Fork E Position Circuit

Why rod 5 position can disagree with an engaged gear

Low digital output from transmission rod 5

When rod 5 feedback stays high instead of pulsing

Rod 5 pulse frequency outside its valid window

Shift Fork E Position Sensor Incorrect Neutral Position Indicated

Shift Fork E Stuck

Unrequested rod 5 movement and repeated correction

Clutch A Pressure Engagement Too High

Clutch A Pressure Disengagement Too High