What it means
The control module detects a circuit-high condition in the Bank 1 intake valve control solenoid circuit.
At a glance
- Usually lights the check-engine light
- Affects emissions; the car can fail an emissions test
How it works
The bank 1 intake valve control solenoid circuit operates the intake valve-control mechanism. P0077 sets when the control module detects voltage higher than expected in that circuit, often because a wire is shorted to battery power.
Common causes
Most likely first.
- Wiring shorted to battery
- Connector pins corroded - high contact resistance
- Supply wire pinched against B+ source
Symptoms
- Check-engine light on
- Reduced engine power
- Rough idle or hesitation
- Poor acceleration
How to diagnose it
- Save freeze-frame data and check for related valve-control codes, noting whether reduced power or rough running occurred.
- Inspect the bank 1 intake solenoid connector and harness for pinched insulation or contact with a battery-positive supply.
- With the wiring diagram, test the control circuit for a short to voltage using the manufacturer's procedure.
- Inspect terminals for corrosion, looseness, or damage and check circuit continuity to locate a break or poor connection.
- Test the solenoid coil against the manufacturer's specification; if it passes, investigate the valve-control mechanism for binding.
Common fixes
- Repair wiring shorted to battery power in the bank 1 intake solenoid circuit.
- Replace damaged or corroded connector terminals.
- Reroute and secure wiring pinched against a power source.
- Replace the bank 1 intake valve control solenoid if it fails testing.
Can I keep driving?
Reduced power, rough idle, or hesitation can affect safe acceleration, so avoid hard acceleration and demanding trips. Stop if the engine runs severely rough or loses enough power to make traffic unsafe.
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.