P08DC: Shift Solenoid K Control Circuit High

The monitored control line of shift solenoid K sits closer to supply voltage than it should, for instance because it touches a powered wire or, depending on the driver design, because the coil is open. No manufacturer documents this code publicly. GM treats the solenoid A version, P0974, as open or power short and fails it after 1.2 of 1.5 seconds, but lights the MIL only after two trips. Ford's P0974 means a short to power only, because Ford reports opens separately. CARB requires this circuit check. P08DB is the low counterpart, P08DD the open-circuit code. A valve shorted to power may stay energised, giving a wrong gear or harsh engagements.

Symptoms

• Check engine or transmission warning light on
• Wrong gear or harsh engagement
• Possible limp mode

Most likely causes

• Control wire touching a powered conductor
• Open coil on systems that read opens as high
• TCM low-side driver no longer pulls the line down

What to check, in order

Start with the simplest. You can tick off each step.

1. Check the fluid level and condition according to the manufacturer
2. Check the sensor's ground and make sure the signal wire is not receiving voltage from another circuit.
3. Check the transmission connector
4. Read the data with a transmission-compatible scanner
5. Measure the solenoid valve circuit
6. Leave opening the transmission to a specialized repair shop

Good to know

• Repair difficulty: hard
• It can trigger limp mode.
• It affects emissions.

What each character of P08DC means

• P: Powertrain: engine and transmission
• 0: Generic code: same on every make
• 8: Transmission
• DC: Specific fault in that system

Frequently asked questions

Can I keep driving with code P08DC?

Drive as little as possible and gently. If the transmission slips or stays in one gear, go slowly to a repair shop or call for a tow truck.

What causes code P08DC?

The most common causes are: control wire touching a powered conductor; open coil on systems that read opens as high; tCM low-side driver no longer pulls the line down.

Related codes

• P08D3Shift Solenoid J Control Circuit High
• P08D8Shift Solenoid K Electrical
• P08DAShift Solenoid K Control Circuit Range/Performance
• P08DBShift Solenoid K Control Circuit Low
• P08DDShift Solenoid K Control Circuit/Open
• P08E5Shift Solenoid L Control Circuit High
• P0974Shift Solenoid A Control Circuit High

Sources

• gsi.ext.gm.com: 16OBDG03 Transmission Diagnostics
• fordservicecontent.com: OBD Operations Summary Gasoline 2020 2023
• law.cornell.edu: 13 CCR 1968.2

Values and procedures vary by manufacturer. If it affects brakes, steering, fuel or high voltage, see a professional. Updated: 2026-11-04. How we build these pages.