DTC Troubleshooting: P2238, P2241 (V6: PZEV models)

DTC Troubleshooting: P2238, P2241

DTC P2238: Rear A/F Sensor (Bank 1, Sensor 1) IP Circuit Low Voltage
DTC P2241: Front A/F Sensor (Bank 2, Sensor 1) IP Circuit Low Voltage

NOTE:

	Before you troubleshoot, record all freeze data and any on-board snapshot, and review the general troubleshooting information.
	Information marked with an asterisk (*) applies to the front bank (Bank 2).

DTC Description	Confirmed DTC	Pending DTC	Freeze Frame
P2238 Rear A/F Sensor (Bank 1, Sensor 1) IP Circuit Low Voltage
P2241 Front A/F Sensor (Bank 2, Sensor 1) IP Circuit Low Voltage

Problem verification:

Problem verification

?1.	Press the engine start/stop button to select the ON mode.

?2.	Clear the DTC with the HDS.

?3.

Check for Pending or Confirmed DTCs with the HDS.

DTC Description	Confirmed DTC	Pending DTC	Freeze Frame
P2238 Rear A/F Sensor (Bank 1, Sensor 1) IP Circuit Low Voltage
P2241 Front A/F Sensor (Bank 2, Sensor 1) IP Circuit Low Voltage

Is DTC P2238 and/or P2241^* 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), the PGM-FI subrelay, and the PCM.?

Shorted wire check (IPB1 (IPB2)^* line):

Shorted wire check (IPB1 (IPB2)^* line)

?1.	Press the engine start/stop button to select the OFF mode.

?2.	Jump the SCS line with the HDS.

?3.

Disconnect the following connectors.

PCM connector C (51P)

A/F sensor (Sensor 1) 8P connector

?4.

Check for continuity between test points 1 and 2.

Test condition	OFF mode
	A/F sensor (Sensor 1) 8P connector: disconnected
	PCM connector C (51P): disconnected
Test circuit	IPB1 (IPB2)^*
Test point 1	PCM connector C (51P) No. 37 (GRN)
	PCM connector C (51P) No. 38 (PUR)^*
Test point 2	Body ground

Is there continuity?


	YES

Repair a short in the IPB1 (IPB2)^* wire between the PCM (C37 (C38)^*) and the A/F sensor (Sensor 1), then do the repair verification.


	NO

The IPB1 (IPB2)^* wire is OK. Go to step 3.

PCM internal circuit check:

?1.	Exit the SCS mode with the HDS.

?2.	Reconnect PCM connector C (51P).

?3.	Press the engine start/stop button to select the ON mode.

?4.

Measure the voltage between test points 1 and 2.

Test condition	ON mode
	A/F sensor (Sensor 1) 8P connector: disconnected
Test circuit	IPB1 (IPB2)^*
Test point 1	Rear A/F sensor (Bank 1, Sensor 1) 8P connector No. 2 (GRN)
	Front A/F sensor (Bank 2, Sensor 1) 8P connector No. 2 (PUR)^*
Test point 2	Body ground

Is there about 0.2 V or less?


	YES

Update the PCM if it does not have the latest software, or substitute a known-good PCM, then do the repair verification.


	NO

The PCM internal circuit is OK. Replace the A/F sensor (Sensor 1), then do the repair verification.

Repair verification (OBD STATUS check):

?1.	Press the engine start/stop button to select the OFF mode.

?2.	Reconnect all connectors.

?3.	Exit the SCS mode with the HDS.

?4.	Press the engine start/stop button to select the ON mode.

?5.	Reset the PCM with the HDS.

?6.	Do the PCM idle learn procedure.

?7.

Monitor the OBD STATUS for DTC P2238 and/or P2241^* in the DTCs MENU with the HDS.

DTC Description	OBD Status
P2238 Rear A/F Sensor (Bank 1, Sensor 1) IP Circuit Low Voltage
P2241 Front A/F Sensor (Bank 2, Sensor 1) IP Circuit Low Voltage

Does the HDS indicate PASSED, FAILED, or NOT COMPLETED?


	PASSED (P2238)

Troubleshooting is complete. If the PCM was substituted, replace the original PCM. Check for other DTC after this troubleshooting. If any other Pending or Confirmed DTCs were indicated, go to the indicated DTC's troubleshooting.?


	PASSED (P2241)


	FAILED (P2238)

Go to step 1 and recheck. If the PCM was updated, substitute a known-good PCM, then check the OBD STATUS again.


	FAILED (P2241)

Go to step 1 and recheck. If the PCM was updated, substitute a known-good PCM, then check the OBD STATUS again.


	NOT COMPLETED

Keep idling until a result comes on.