Summary
P0106 means the manifold absolute pressure (MAP) sensor reading doesn't match what the PCM expects for current engine RPM, throttle position, and load. The sensor is working electrically, but its values are implausible. The most common cause is a vacuum leak (35%), followed by a failed MAP sensor (30%) and a clogged vacuum hose to the sensor (15%). Start by checking the vacuum hose and connections to the MAP sensor — a disconnected or cracked hose is a quick, free fix.
Severity: Moderate
Safe to drive: Yes, short distances — engine may run rough and idle poorly
Repair cost: $0–$350 depending on cause
DIY difficulty: Easy to Moderate
What does P0106 mean?
The MAP sensor measures the pressure inside the intake manifold. At idle with the throttle closed, manifold pressure is low (high vacuum). Under wide-open throttle, manifold pressure rises close to atmospheric. The PCM uses this data to calculate engine load and adjust fuel delivery and ignition timing.
P0106 is a rationality check code. The PCM compares the MAP sensor reading against what it expects based on other inputs — throttle position, RPM, and (on vehicles with one) MAF sensor data. When the MAP reading consistently disagrees with these cross-checks, P0106 is set.
This is different from P0107 (low input) or P0108 (high input), which indicate the electrical signal itself is out of range. P0106 means the voltage is within the valid range, but the pressure reading doesn't match reality. A vacuum leak, a clogged hose, or a drifting sensor are the usual suspects.