P288A

Code

Generic P — Powertrain

Park Lock/Pawl Actuator Circuit High

Brand: Generic

Type: P — Powertrain

Views: UK: 22 EN: 78 RU: 28

AI status

Completed

ready

Completed 100%

Page language: EN

Causes

Short to battery (control wire contacting B+)
Failed/shorted park lock/pawl actuator coil
Faulty PCM/TCM driver transistor or internal electronics
Poor or corroded connector(s) or pin(s) causing abnormal voltage readings
Damaged wiring harness (chafing, pinched, water ingress)
Aftermarket modifications or incorrect replacement actuator

Symptoms

MIL/Check Engine or transmission warning lamp illuminated
Transmission may fail to engage or release Park (vehicle may be stuck in Park or fail to lock into Park)
Key removal or start inhibit related to Park/shift interlock may not work
Shifter position indicator incorrect or inconsistent
Possible inability to shift out of Park or unexpected Park engagement

What to check

Retrieve freeze-frame and live data with a capable scan tool; confirm P288A and any related transmission codes
Visual inspection of transmission harness and connector at the actuator for corrosion, bent pins, water, or damage
Inspect fuse(s) and relay(s) powering the transmission/park circuit
Wiggle test harness while monitoring code or live data to reproduce fault
Backprobe actuator connector and measure voltage and ground at rest and when commanded by scan tool
Measure actuator coil resistance with harness disconnected

Signal parameters

Typical control circuit voltage: ~0 V when OFF; up to battery voltage (~11–14.5 V) when power applied — expected commanded voltages depend on vehicle design
Actuator coil resistance (typical range): ~5–100 ohms (varies by design) — compare to OEM spec
Expected current draw when energized: generally 0.5–3 A (varies by actuator) — excessive or near-zero current indicates fault
Short-detection threshold: voltage higher than expected for commanded state (consult OEM for exact voltage trip)

Diagnostic algorithm

Connect scan tool, note freeze-frame and any related codes (PRNDL, TCM communication, other transmission solenoid faults). Do not assume final cause.
Perform visual inspection: check connector at park pawl actuator for corrosion, loose pins, water ingress, or damaged wiring; repair as needed.
With ignition ON (engine off), backprobe the control and power circuits at the actuator connector. Observe voltage at rest and while commanding the actuator ON/OFF with the scan tool. Record values.
If control circuit shows battery voltage when it should be low (or otherwise higher than spec), disconnect the actuator and repeat measurements. If voltage returns to normal with actuator disconnected, suspect actuator short or wiring to actuator.
Measure coil resistance of the actuator with it disconnected from harness. Compare to OEM spec. Very low resistance indicates a shorted coil; open circuit indicates broken coil.
Check for short to B+: disconnect harness and measure resistance between the control wire and vehicle battery positive; low resistance indicates a short to B+ somewhere in harness.
Inspect wiring along harness routing for chafing against body/frame or melting from heat. Repair damaged sections and replace pliable connectors/pigtails as required.
Bench-test the actuator by applying specified voltage per OEM procedure (use inrush current monitoring and correct polarity). If actuator is faulty, replace it.
If actuator and harness test OK, test PCM/TCM driver output. Confirm driver switches correctly and is not sourcing unexpected voltage. If driver is faulty, verify all wiring and replace control module only after eliminating wiring/actuator faults.
Clear codes and perform road test or actuator exercise to confirm repair; monitor for recurrence and re-check freeze-frame if code returns.

Likely causes

Control wire shorted to B+ at harness or connector
Corroded transmission connector causing intermittent high voltage reading
Actuator internal short or low resistance coil
PCM/TCM output driver failed after actuator fault
Damaged insulation where harness rubs against body or frame

Fault status

⚠️ Status

Park Lock/Pawl Actuator Circuit High — high voltage detected on the park pawl control circuit. Possible short to battery, failed actuator, wiring or PCM/TCM driver fault.

🟡 Repair difficulty: Medium

⏱️ Diagnostic time: 0.5-2.5 hours