DTC Troubleshooting: P2237

DTC P2237: A/F Sensor (Sensor 1) AFS Circuit High Voltage

NOTE: Before you troubleshoot, review the general troubleshooting information.

DTC Description	Confirmed DTC	Pending DTC
P2237 A/F Sensor (Sensor 1) AFS Circuit High Voltage

Problem verification:

Problem verification

?1.	Turn the vehicle to the ON mode.

?2.	Clear the DTC with the HDS.

?3.	Start the engine, and wait for 1 minute.

?4.

Check for Pending or Confirmed DTCs with the HDS.

DTC Description	Confirmed DTC	Pending DTC
P2237 A/F Sensor (Sensor 1) AFS Circuit High Voltage

Is DTC P2237 indicated?


	YES

The failure is duplicated. Go to step 2.


	NO

Intermittent failure, the system is OK at this time. Check for poor connections or loose terminals at the A/F sensor (Sensor 1) and the PCM. If the on-board snapshot of this DTC is recorded, try to reproduce the failure under the same conditions with the on-board snapshot.?

Open wire check (AFS+ line):

Open wire check (AFS+ line)

?1.	Turn the vehicle to the OFF (LOCK) mode.

?2.	Jump the SCS line with the HDS, and wait more than 1 minute.

?3.

Disconnect the following connectors.

A/F sensor (Sensor 1) 4P connector

PCM connector C (51P)

?4.

Check for continuity between test points 1 and 2.

Test condition	Vehicle OFF (LOCK) mode
	A/F sensor (Sensor 1) 4P connector: disconnected
	PCM connector C (51P): disconnected
Test point 1	A/F sensor (Sensor 1) 4P connector No. 2
Test point 2	PCM connector C (51P) No. 48

Is there continuity?


	YES

The AFS+ wire is OK. Go to step 3.


	NO

Repair an open in the AFS+ wire between the PCM (C48) and the A/F sensor (Sensor 1).?

Open wire check (AFS- line):

Open wire check (AFS- line)

?1.

Check for continuity between test points 1 and 2.

Test condition	Vehicle OFF (LOCK) mode
	A/F sensor (Sensor 1) 4P connector: disconnected
	PCM connector C (51P): disconnected
Test point 1	A/F sensor (Sensor 1) 4P connector No. 1
Test point 2	PCM connector C (51P) No. 47

Is there continuity?


	YES

The AFS- wire is OK. Go to step 4.


	NO

Repair an open in the AFS- wire between the PCM (C47) and the A/F sensor (Sensor 1).?

A/F sensor (Sensor 1) check (substitution):

A/F sensor (Sensor 1) check (substitution)

?1.	Substitute a known-good A/F sensor (Sensor 1).

?2.	Reconnect all connectors.

?3.	Turn the vehicle to the ON mode.

?4.	Reset the PCM with the HDS.

?5.	Do the PCM idle learn procedure.

?6.

Check for Pending or Confirmed DTCs with the HDS.

DTC Description	Confirmed DTC	Pending DTC
P2237 A/F Sensor (Sensor 1) AFS Circuit High Voltage

Is DTC P2237 indicated?


	YES

Check for any authorized service information related to the DTCs or symptoms you are troubleshooting, or substitute a known-good PCM then recheck. If DTC P2237 goes away and the PCM was substituted, replace the original PCM.?


	NO

Replace the original A/F sensor (Sensor 1).?