DTC Advanced Diagnostics: P2237 (K20C2) - Honda Civic FC/FK 2016-2021

DTC Advanced Diagnostics: P2237

DTC P2237:Air/Fuel Ratio (A/F) Sensor (Sensor 1) IP Circuit High Voltage

General Description

The air/fuel ratio (A/F) sensor (sensor 1) is installed in the exhaust manifold and detects oxygen content in the exhaust gas. The A/F sensor (sensor 1) transmits a signal to the powertrain control module (PCM), and the PCM controls fuel injection duration by comparing the target air/fuel ratio with the A/F sensor (sensor 1) signal. If the IP terminal voltage is within a specified range when the A/F sensor (sensor 1) pump cell voltage is excessively high, the PCM detects a malfunction and stores a DTC.

Monitor Execution, Sequence, Duration, DTC Type

Execution	Continuous
Sequence	None
Duration	15 seconds or more
DTC Type	Two drive cycles, MIL on

Enable Conditions

Condition	Minimum	Maximum
12 volt battery voltage [BATTERY]	9.0 V	–
State of the engine	Running

[ ]: HDS Parameter

Malfunction Threshold

The IP terminal voltage is between 1.93 - 2.07 V for at least 15 seconds.

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) failure
	A/F sensor (sensor 1) IP line open
	PCM internal circuit failure

Confirmation Procedure

Operating Condition

Start the engine. Hold the engine speed [ENGINE SPEED] at 3,000 rpm without load (CVT in P or N, M/T in neutral) until the radiator fan comes on, then let it idle.

With the HDS

None.

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 or by disconnecting the 12 volt battery.