P1299moderate severityPowertrain
Vacuum Leak Found IAC At Max
on 2012 Jeep Wrangler 3.6L V6 · 4WD
What this code means
The PCM has determined that the idle air control motor is at its maximum closed position but the engine idle is still too high. This strongly indicates a vacuum leak is allowing unmetered air into the engine.
Symptoms
- Check Engine Light
- High idle speed
- Idle does not come down
- Rough idle
- Hissing sound from engine bay
Common causes
- Vacuum hose cracked or disconnected
- Intake manifold gasket leak
- Throttle body gasket leak
- Brake booster vacuum leak
- PCV valve or hose leak
Diagnostic steps
- Perform smoke test on intake system to locate vacuum leak
- Inspect all vacuum hoses for cracks or disconnections
- Check intake manifold gasket area with carb cleaner spray
- Test brake booster vacuum hose
- Inspect PCV system
Repair notes
Locate and repair the vacuum leak that is causing the high idle condition.
Other Powertrain codes on this vehicle
P0001
Fuel Volume Regulator Control Circuit/Open
P0002
Fuel Volume Regulator Control Circuit Range/Performance
P0003
Fuel Volume Regulator Control Circuit Low
P0004
Fuel Volume Regulator Control Circuit High
P0010
Intake Camshaft Position Actuator Circuit/Open Bank 1
P0011
Intake Camshaft Position Timing Over-Advanced Bank 1
P0012
Intake Camshaft Position Timing Over-Retarded Bank 1
P0013
Exhaust Camshaft Position Actuator Circuit/Open Bank 1
P0014
Exhaust Camshaft Position Timing Over-Advanced Bank 1
P0015
Exhaust Camshaft Position Timing Over-Retarded Bank 1