P0140 Code – O2 Sensor Circuit No Activity Detected
Acasa › Blog › obd2 The P0140 code indicates that the oxygen sensor (O2 sensor) located on Bank 1 Sensor 2 is showing no activity. This sensor is positioned after…
OBD2 is the standard on-board diagnostic system in modern vehicles. The engine control unit logs faults as trouble codes (such as P0171 or P0420), and a scan tool plugged into the OBD port reads them along with live engine data.
This page collects our OBD2 guides: individual code explanations (P0102, P0125, P0129, P0138, P0171, P0420, P0507, P059F and more), brand-specific code guides for Ford and Opel, winter-related codes, live-data checks, and notes on scan tools and VAG security gateway (SFD/SGW) access.
A trouble code does not tell you which part to replace. It only shows where the control unit noticed a problem. That is why each guide goes beyond the code itself: what to check first, which parameters to watch, and when the real cause is somewhere else. The articles are written for roadside and mobile diagnostics, based on real cases.
P0124 Code – Throttle Position Sensor Circuit Intermittent
Acasa › Blog › obd2 The P0124 code indicates that the Engine Control Unit (ECU) has detected an intermittent or unstable signal from the Throttle Position Sensor (TPS) circuit. Unlike…
P0123 Code – Throttle Position Sensor High Input
Acasa › Blog › obd2 The P0123 code indicates that the Engine Control Unit (ECU) has detected a high voltage signal from the Throttle Position Sensor (TPS). A high input…
P0122 Code – Throttle Position Sensor Low Input
Acasa › Blog › obd2 The P0122 code indicates that the Engine Control Unit (ECU) has detected a low voltage signal from the Throttle Position Sensor (TPS). A low input…
P0121 Code – Throttle Position Sensor Range/Performance Problem
Acasa › Blog › obd2 The P0121 code indicates that the Engine Control Unit (ECU) has detected that the Throttle Position Sensor (TPS) signal is outside the expected range or…
P0120 Code – Throttle Position Sensor Circuit Malfunction
Acasa › Blog › obd2 The P0120 code indicates that the Engine Control Unit (ECU) has detected a malfunction in the Throttle Position Sensor (TPS) circuit. The TPS monitors the…
P0118 Code – Engine Coolant Temperature Sensor High Input
Acasa › Blog › obd2 The P0119 code indicates that the Engine Control Unit (ECU) has detected an intermittent or unstable signal from the Engine Coolant Temperature (ECT) sensor circuit.…
P0117 Code – Engine Coolant Temperature Sensor Low Input
Acasa › Blog › obd2 The P0117 code indicates that the Engine Control Unit (ECU) has detected a low voltage signal from the Engine Coolant Temperature (ECT) sensor. A low…
P0116 Code – Engine Coolant Temperature Range/Performance
Acasa › Blog › obd2 The P0116 code indicates that the Engine Control Unit (ECU) has detected that the Engine Coolant Temperature (ECT) sensor signal is outside the expected range…
P0115 Code – Engine Coolant Temperature Circuit Malfunction
Acasa › Blog › obd2 The P0115 code indicates that the Engine Control Unit (ECU) has detected a malfunction in the Engine Coolant Temperature (ECT) sensor circuit. The ECT sensor…