Question 1

What does Global fault code P0101 mean?

Accepted Answer

P0101 (Induction): Hesitation; Poor MPG; Black smoke. Fix: MAF Circuit Range.

LOGIC: Airflow signal doesn't match RPM/Throttle logic.

ACTION: Inspect for intake leaks.

FIX: Clean MAF sensor wire.

Question 2

What does Global fault code P0128 mean?

Accepted Answer

P0128 (Cooling): Engine takes too long to warm up; A/C not cooling well. Fix: Coolant Temp Below Thermostat Range.

LOGIC: Thermostat is stuck open, preventing the engine from reaching operating temp.

ACTION: Check coolant level and thermostat operation.

FIX: Replace Thermostat and Coolant.

Question 3

What does Global fault code P0171 mean?

Accepted Answer

P0171 (Fuel): Shaking at idle; Lean hesitation; Poor acceleration. Fix: System Too Lean (Bank 1).

LOGIC: Oxygen sensor reports too much air/too little fuel; fuel trims are maxed out.

ACTION: Check for vacuum leaks or a dirty MAF sensor.

FIX: Clean MAF Sensor or replace a cracked Intake Boot.

Question 4

What does Global fault code P0171 / P0174 mean?

Accepted Answer

P0171 / P0174: Hesitation on acceleration; Hissing sound from engine; Lean misfires; Poor idle. Fix: System Too Lean (Bank 1 or 2).

LOGIC: The Oxygen sensor sees too much unburned oxygen. The PCM has reached its +25% fuel trim limit trying to compensate.

ACTION: 1. Check for vacuum leaks (PCV/Intake). 
2. Inspect Mass Air Flow (MAF) sensor for dirt. 
3. Test fuel pump pressure.

FIX: Clean MAF sensor; replace cracked intake boots; replace fuel pump/filter.

Question 5

What does Global fault code P0217 mean?

Accepted Answer

P0217: Engine Shutdown. Fix: LOGIC: Engine Over-Temperature condition.

ACTION: Check for coolant leaks; verify electric cooling fan operation.

Question 6

What does Global fault code P0300 mean?

Accepted Answer

P0300: Engine shaking/shuddering; Flashing Check Engine Light; Poor fuel economy; Rotten egg smell (catalyst stress). Fix: Random or Multiple Cylinder Misfire Detected.

LOGIC: The Crankshaft Position Sensor detects a decrease in RPM during power strokes, indicating incomplete combustion.

ACTION: 1. Check for vacuum leaks. 
2. Inspect spark plug condition. 
3. Test fuel pressure.

FIX: Replace spark plugs/coils; repair vacuum leaks; clean fuel injectors.

Question 7

What does Global fault code P0606 mean?

Accepted Answer

P0606: No Start. Fix: LOGIC: Internal ECM/PCM processor fault.

ACTION: Check main power/grounds; if power is clean, the module is "bricked."

Question 8

What does Global fault code P2181 mean?

Accepted Answer

P2181 (Cooling): Slow Warm-up Fix: LOGIC: Cooling System Performance.

ACTION: Replace thermostat. Verify the cooling fan isn't running constantly.

Question 9

What does Global fault code U0107 mean?

Accepted Answer

U0107 (Network / Comm): Dead Pedal. The engine idles, but pressing the gas pedal does absolutely nothing. Fix: Lost Communication with Throttle Actuator Control Module.

LOGIC: The PCM has lost the CAN-bus data link to the electronic throttle body.

ACTION: Check the fuse for the "Electronic Throttle" and inspect the connector at the throttle body for pins that have backed out.

Global Fault Codes

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Code	System	Symptom	Full fix
P0101	Induction	Hesitation; Poor MPG; Black smoke.	View fix
P0128	Cooling	Engine takes too long to warm up; A/C not cooling well.	View fix
P0171	Fuel	Shaking at idle; Lean hesitation; Poor acceleration.	View fix
P0171 / P0174	—	Hesitation on acceleration; Hissing sound from engine; Lean misfires; Poor idle.	View fix
P0217	—	Engine Shutdown.	View fix
P0300	—	Engine shaking/shuddering; Flashing Check Engine Light; Poor fuel economy; Rotten egg smell (catalyst stress).	View fix
P0606	—	No Start.	View fix
P2181	Cooling	Slow Warm-up	View fix
U0107	Network / Comm	Dead Pedal. The engine idles, but pressing the gas pedal does absolutely nothing.	View fix