DTC P2A00: Air/Fuel Ratio (A/F) Sensor (Sensor 1) Circuit Range/Performance Problem: General Description
The air/fuel ratio (A/F) sensor has a linear signal output in relation to the oxygen concentration. The engine control module (ECM) computes the air/fuel ratio from A/F sensor output voltage and uses the fuel feedback control to improve exhaust emissions. The ECM monitors A/F sensor output voltage during deceleration with the throttle fully closed, and if the output voltage deviates greatly from normal oxygen concentration levels, it detects a malfunction and stores a DTC.
* Output to the scan tool exhibits a relationship between the A/F sensor output and oxygen concentration, which is opposite to the characteristic shown in the graph. That is, a deviation toward the rich side increases the output voltage and one toward the lean side decreases the output voltage as the stoichiometric ratio is 0.
| Execution | Once per driving cycle |
| Sequence | None |
| Duration | 3.5 seconds or more |
| DTC Type | Two drive cycles, MIL ON |
| OBD Status | PASSED/FAILED/EXECUTING/OUT OF (TEST) CONDITION |
| Condition | Minimum | Maximum |
|---|---|---|
| Elapsed time after starting the engine | 60 seconds | - |
| Engine coolant temperature | 156°F (69°C) | - |
| Intake air temperature | -13°F (-25°C) | - |
| Engine speed | - | 4,350 rpm |
| Vehicle speed | 30 mph (48 km/h) | - |
| Fuel feedback | During deceleration | |
| No active DTCs | P0112, P0113, P0117, P0118, P0122, P0123, P0133, P0134, P0135, P0171, P0172, P0222, P0223, P0300, P0301, P0302, P0303, P0304, P0443, P0496, P1109, P1157, P1172, P2101, P2108, P2118, P2122, P2123, P2127, P2128, P2135, P2138, P2176, P2195, P2227, P2228, P2229, P2238, P2252, U0107 | |