What it means
The current through pressure control solenoid L does not match the commanded value within tolerance. Coil resistance drift or high-resistance contact.
At a glance
- Usually lights the check-engine light
- The engine or gearbox may go into limp mode
How it works
The TCM varies current through pressure control solenoid L to adjust transmission pressure. P08C0 sets when the measured current does not track the commanded value within tolerance, which can result from coil resistance drift or a high-resistance connection.
Common causes
Most likely first.
- Coil resistance changed by thermal stress
- High-resistance contact in solenoid connector
- Sensor element aged beyond calibration window
Symptoms
- Check engine or transmission warning light on
- Harsh, delayed, or missing shifts
- Possible limp mode (locked in one gear)
- Slipping or shuddering during gear changes
How to diagnose it
- Review freeze-frame data and scan-tool records for solenoid L command and current response when P08C0 set.
- Inspect the solenoid L connector and harness for corrosion, loose terminals, fluid intrusion, or damaged wiring that could add resistance.
- Measure solenoid L coil resistance and compare it with the manufacturer’s specification, checking for abnormal change as the transmission warms.
- Test wiring and terminal voltage drop under the manufacturer’s specified conditions to locate a high-resistance connection.
- If the circuit and coil meet specification, check solenoid L response and related pressure feedback for a performance fault in the valve body.
Common fixes
- Clean and secure a high-resistance solenoid L connector if the terminals remain serviceable.
- Repair damaged or corroded wiring in the L control circuit.
- Replace solenoid L if its coil resistance drifts outside specification.
- Repair valve body wear if electrical current is correct but L’s pressure response remains outside specification.
Can I keep driving?
Limit driving if shifts are harsh, slipping, delayed, or the transmission enters limp mode; incorrect current control can lead to poor hydraulic pressure and further transmission wear. Have the fault checked soon.
A code shows where the control module detected a fault, not always which part failed. Check the causes in order and confirm with a test before replacing parts. Have several codes? Check them together
This is a generic code: it means the same on every make. The car’s maker may add more detail in its own service information.