P27C0: Pressure Control Solenoid N Control Circuit High

What it means

The control circuit for pressure control solenoid N is reporting a high electrical condition.

At a glance

• Usually lights the check-engine light

How it works

The TCM controls pressure control solenoid N through an electrical circuit to regulate transmission pressure. This code sets when the circuit reports a high electrical condition, which may result from a control wire shorted to battery voltage, an open solenoid coil or a poor connector contact.

Common causes

Most likely first.

1. Control wire shorted to B+
2. Open solenoid coil
3. Connector pins corroded - high contact resistance

Symptoms

• Transmission warning light may illuminate
• Harsh or delayed shifting
• Transmission may enter limp mode

How to diagnose it

1. Save freeze-frame data and scan for other solenoid circuit codes to check whether the high condition is isolated to solenoid N.
2. Inspect the solenoid N harness for damaged insulation or a wire contacting a battery-voltage source, and check the connector for corrosion or loose terminals.
3. Check the solenoid N coil for an open circuit using the manufacturer’s procedure and compare the result with its specification.
4. Test the control wire for a short to battery voltage and verify connector continuity using the vehicle wiring diagram.
5. If the solenoid and harness pass, test the TCM output and power circuits to identify a module-side cause.

Common fixes

• Repair the control wire if it is shorted to battery voltage.
• Restore clean, secure contact at a corroded or loose solenoid N connector.
• Replace pressure control solenoid N if its coil is confirmed open.
• Repair the TCM circuit or replace the module only after the solenoid and wiring test correctly.

Can I keep driving?

Avoid towing, high loads and hard acceleration if the transmission shifts harshly or enters limp mode; solenoid N may not control pressure correctly. Stop if the vehicle slips severely or cannot maintain drive.