What it means
The TCM detects an open circuit in the control wiring of pressure control solenoid L. No current flows when the solenoid is commanded.
At a glance
- Usually lights the check-engine light
- The engine or gearbox may go into limp mode
How it works
The TCM sends current through the control circuit to operate pressure control solenoid L. P08BF sets when the circuit is open and current cannot flow when L is commanded, so the solenoid cannot regulate its hydraulic pressure as intended.
Common causes
Most likely first.
- Open in solenoid control wire
- Open solenoid coil
- Pin pushed back out of connector body
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
- Scan transmission codes and check freeze-frame data and solenoid L commands to confirm when the open circuit was detected.
- Inspect the solenoid L connector for a pin pushed back into the housing, a loose latch, corrosion, or a disconnected plug.
- Trace the solenoid L control wire and harness for breaks, chafing, or damaged sections between the TCM and transmission connector.
- With power isolated as specified by the manufacturer, check continuity through the solenoid L coil and control wiring against the wiring diagram.
- If wiring and coil continuity are intact, verify terminal contact and test the TCM output using the manufacturer’s procedure.
Common fixes
- Reseat a pushed-back pin or secure a loose solenoid L connector.
- Repair the open or broken solenoid L control wire.
- Replace pressure control solenoid L if its coil is open.
- Repair a failed terminal or TCM output only after tests isolate that fault.
Can I keep driving?
Avoid driving if the transmission shifts harshly, slips, misses shifts, or enters limp mode; solenoid L cannot control pressure while its circuit is open, and continued slipping can damage the transmission. Arrange prompt repair.
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.