DTC Advanced Diagnostics: P2626
DTC P2626:Air/Fuel Ratio (A/F) Sensor (Sensor 1) Circuit (LAF-CA, LAFCP) Open Malfunction

General Description


The driver IC for air/fuel ratio (A/F) sensor (sensor 1) is built into the powertrain control module (PCM). The diagnosis data acquired by the driver IC are called up directly by application specific integrated circuit (ASIC) chip and are considered along with the measured values in order to detect faults in the system and the sensor. At the same time, a distinction is made between SPI faults (transmission faults), chip faults (ex. incorrect placement of components or faulty driver IC), short circuits, as well as overloads at the individual pins. If the calculated parallel resistance between LAF CP and LAF CA is a specified value, the PCM stores a DTC.

Monitor Execution, Sequence, Duration, DTC Type
Execution
Continuous
Sequence
None
Duration
0.5 second or more
DTC Type
Two drive cycles, MIL on

Enable Conditions
Condition
Minimum
Maximum
12 volt battery voltage [Battery]
10.7 V
16.1 V
Other
A/F sensor (sensor 1) is in active condition (heated up enough)
[ ]: HDS Parameter

Malfunction Threshold
The calculated parallel resistance between LAF CP and LAF CA is greater than 296 ?.

Possible Cause
NOTE: The causes shown may not be a complete list of all potential problems, and it is possible that there may be other causes.
A/F sensor (sensor 1) LAF CP line open
A/F sensor (sensor 1) LAF CA line open
A/F sensor (sensor 1) failure
PCM internal circuit failure

Confirmation Procedure
Operating Condition
Start the engine. Hold the engine speed [Engine Speed] at 3,000 rpm without load (in neutral) until the radiator fan comes on, then let it idle.

Diagnosis Details
Conditions for setting the DTC
When a malfunction is detected during the first drive cycle, a Pending DTC is stored in the PCM memory. If the malfunction returns in the next (second) drive cycle, the MIL comes on and a Confirmed DTC and the freeze data are stored.

Conditions for clearing the DTC
The MIL is cleared if the malfunction does not return in three consecutive trips in which the diagnostic runs. The MIL, the Pending DTC, the Confirmed DTC, and the freeze data can be cleared with the scan tool Clear command.