Shift Solenoid Control Circuit High
The P0980 code indicates that the Powertrain Control Module (PCM) has detected a high voltage condition in the control circuit of the shift solenoid 'C' (or a specific solenoid depending on the vehicle). This solenoid is responsible for regulating hydraulic pressure to engage specific gears in the automatic transmission. A high voltage reading suggests a short to power, a faulty solenoid, or an issue with the wiring or PCM. This can lead to harsh shifting, transmission slippage, or failure to shift, potentially causing internal transmission damage if ignored.
1. Symptoms You Will Notice
- Check Engine Light illuminated
- Harsh or erratic shifting
- Transmission stuck in a single gear (limp mode)
- Delayed engagement when shifting into drive or reverse
- Decreased fuel economy
2. Most Common Causes
- Faulty or damaged shift solenoid 'C'
- Short circuit to voltage in the control circuit wiring
- Open circuit in wiring or corroded connectors
- Transmission solenoid connector with bent, dirty, or loose pins
- Faulty transmission control module (TCM) or powertrain control module (PCM)
- Internal transmission mechanical issues affecting the solenoid
3. Step-by-Step Diagnosis
Step 1: Scan for codes and record freeze frame data to confirm P0980 and check for related codes.
Step 2: Visually inspect the transmission wiring harness and connectors for damage, corrosion, or loose pins.
Step 3: Use a multimeter to test the solenoid circuit resistance and compare to manufacturer specs (typically 10-30 ohms).
Step 4: Check for voltage at the solenoid connector with the ignition on; if voltage is present when it shouldn't be, there is a short to power.
Step 5: If wiring and solenoid are okay, test the PCM output by commanding the solenoid on/off with a scan tool and monitoring voltage.
4. Frequently Asked Questions
Is it safe to drive with this code?▼
It is not recommended. Driving with a high voltage condition can cause erratic shifting or transmission damage. If the transmission goes into limp mode, you may lose gears and risk an accident.
How much does it cost to fix?▼
The cost typically ranges from $50 to $150 for diagnosis and repair, but can be higher if the solenoid or PCM needs replacement. Parts alone for a solenoid are $20-$100, and labor is $50-$100.
5. Commonly Affected Makes
This is a generic OBD2 code, potentially applicable to any manufacturer using this diagnostic standard.