P0102 GMC Terrain
MAF Sensor Circuit Low Input · Powertrain Code · Medium · Repair: Easy
What is P0102?
The MAF sensor is reading below its expected range. Could indicate a dirty sensor, air leak, or wiring issue.
When the GMC Terrain triggers code P0102 (maf sensor circuit low input), it typically points to an issue in the powertrain system. Below you'll find the most common causes, symptoms, and repair options specific to the GMC Terrain.
This repair is rated easy, meaning basic tools, no lift needed.
Diagnostic data on this page is compiled from publicly available repair resources and technical service bulletins. Always have a qualified mechanic confirm the diagnosis before authorizing repairs on your GMC Terrain.
Common Causes on GMC Terrain
- Dirty or failed MAF sensor producing low voltage signal
- Disconnected or damaged MAF sensor wiring harness
- Severe air leak before the MAF sensor (unmetered air entering after sensor)
- Corroded MAF sensor connector pins
Symptoms
- Check Engine Light on
- Engine runs rich (black exhaust smoke)
- Very rough idle or stalling
- Reduced engine power mode may activate
- Hard starting
Notes for GMC Terrain
Check the MAF connector for green corrosion on pins — GM connectors in the engine bay are prone to moisture intrusion.