P07A2

Code

Generic P — Powertrain

Transmission Friction Element A Performance/Stuck Off

Brand: Generic

Type: P — Powertrain

Views: UK: 15 EN: 35 RU: 23

AI status

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Page language: EN

Causes

Low or contaminated transmission fluid
Leaking or damaged clutch pack piston seal or return spring
Valve body spool stuck, scored, or clogged by debris
Faulty transmission control solenoid (shift/pressure control) or valve
Internal hydraulic leak or worn clutch friction material
Wiring harness or connector fault to solenoid/pressure sensor

Symptoms

Gear slipping under load or loss of drive in affected gear
Delayed or harsh shifts; inability to hold gear
Higher than normal engine RPM for selected gear
Transmission warning light or MIL illuminated
Vehicle in limp/limited shift mode
Unusual transmission noises or shudder during attempted engagement

What to check

Read and record freeze-frame data and all transmission-related codes
Check transmission fluid level, condition (burnt smell, metal particles) and temperature
Perform a road test while recording commanded clutch apply, line pressure, engine RPM and vehicle speed
Inspect transmission fluid for contamination and magnetic drain plug for debris
Scan and monitor solenoid command duty cycles and pressure sensor readings
Measure solenoid coil resistance and inspect harness/connectors for damage or corrosion

Signal parameters

Commanded apply status (TCM on/off or duty cycle %)
Measured clutch apply pressure (kPa/psi/bar)
Line pressure and modulation pressure
Engine RPM vs vehicle speed (slip detection)
Transmission output speed sensor and input speed sensor
Solenoid coil resistance (ohms) and commanded PWM frequency

Diagnostic algorithm

Retrieve all diagnostic trouble codes and freeze-frame data; note operating conditions when code set.
Clear codes and perform a controlled road test to reproduce code while logging TCM commands and pressure/speed sensors.
Check transmission fluid level and condition; correct level and replace fluid/filter if contaminated or unknown service history.
Visually inspect wiring and connectors to solenoids and pressure sensors for damage, corrosion, or poor connections; repair as needed.
Measure solenoid coil resistance and, if possible, bench-test solenoid operation. Replace suspect solenoids.
Use a scan tool to command Friction Element A on/off while monitoring apply pressure and clutch engagement. If commanded but no pressure rise, suspect hydraulic/mechanical fault.
Perform transmission hydraulic pressure tests (static and apply pressures) at the specified test ports; compare to manufacturer specs.
If hydraulic pressure is low or apply circuit does not respond, remove and inspect valve body and apply piston/seals for sticking, scoring, or debris; clean or rebuild as required.
If internal wear or clutch damage is confirmed (excessive debris, burned friction material, damaged piston or separator plates), plan for partial or full transmission overhaul/replacement.
After repairs, reset codes and perform a full functional verification road test; ensure no reoccurrence and restore proper shift quality.
If electrical checks pass and hydraulics are within spec but code persists, check for TCM software updates or TCM replacement as directed by manufacturer guidance.