DTC P2A00: A/F Sensor Circuit Slow Response (Bank 1 Sensor 1); DTC P2A03: A/F Sensor Circuit Slow Response (Bank 2 Sensor 1): Procedure

WARNING: This page is about a different car, the 2010 Toyota Camry. However, it is still accessible from the selected car via links, so may be relevant.

CHECK ANY OTHER DTCS OUTPUT (IN ADDITION TO DTC P2A00 AND/OR P2A03)

Connect the Techstream to the DLC3.
Turn the ignition switch to ON.
Turn the Techstream on.
Enter the following menus: Powertrain / Engine / Trouble Code.

Read the DTCs.

Result

Display (DTC Output)	Proceed to
P2A00 and/or P2A03	A
P2A00 and/or P2A03 and other DTCs	B

HINT:

If any DTCs other than P2A00 or P2A03 are output, troubleshoot those DTCs first.

B → See step 9

A: Go to next step

INSPECT AIR FUEL RATIO SENSOR (HEATER RESISTANCE)

Disconnect the A/F sensor connector.

Fig 1: Identifying C15 & C35 A/F Sensor Connector
Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

Measure the resistance according to the value(s) in the table below.

Standard resistance (Bank 1 sensor 1)

Tester Connection	Condition	Specified Condition
1 (HA1A) - 2 (+B)	20°C (68°F)	1.8 to 3.4 Ω
1 (HA1A) - 4 (A1A-)	Always	10 kΩ or higher

Standard resistance (Bank 2 sensor 1)

Tester Connection	Condition	Specified Condition
1 (HA2A) - 2 (+B)	20°C (68°F)	1.8 to 3.4 Ω
1 (HA2A) - 4 (A2A-)	Always	10 kΩ or higher

Reconnect the A/F sensor connector.

NG → See step 10

OK: Go to next step

CHECK HARNESS AND CONNECTOR (A/F SENSOR - ECM)

Disconnect the A/F sensor connectors.

Fig 2: Identifying C15, C35 And C55 Connector Terminals
Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
Turn the ignition switch to ON.

Measure the voltage according to the value(s) in the table below.

Standard voltage

Tester Connection	Condition	Specified Condition
C15-2 (+B) - Body ground	Ignition switch ON	11 to 14 V
C35-2 (+B) - Body ground	Ignition switch ON	11 to 14 V

Turn the ignition switch off.
Disconnect the ECM connector.

Measure the resistance according to the value(s) in the table below.

Standard resistance (Check for open)

Tester Connection	Condition	Specified Condition
C15-1 (HA1A) - C55-86 (HA1A)	Always	Below 1 Ω
C15-3 (A1A+) - C55-93 (A1A+)	Always	Below 1 Ω
C15-4 (A1A-) - C55-116 (A1A-)	Always	Below 1 Ω
C35-1 (HA2A) - C55-109 (HA2A)	Always	Below 1 Ω
C35-3 (A2A+) - C55-120 (A2A+)	Always	Below 1 Ω
C35-4 (A2A-) - C55-119 (A2A-)	Always	Below 1 Ω

Standard resistance (Check for short)

Tester Connection	Condition	Specified Condition
C15-1 (HA1A) or C55-86 (HA1A) - Body ground	Always	10 kΩ or higher
C15-3 (A1A+) or C55-93 (A1A+) - Body ground	Always	10 kΩ or higher
C15-4 (A1A-) or C55-116 (A1A-) - Body ground	Always	10 kΩ or higher
C35-1 (HA2A) or C55-109 (HA2A) - Body ground	Always	10 kΩ or higher
C35-3 (A2A+) or C55-120 (A2A+) - Body ground	Always	10 kΩ or higher
C35-4 (A2A-) or C55-119 (A2A-) - Body ground	Always	10 kΩ or higher

Reconnect the ECM connector.
Reconnect the A/F sensor connector.

NG → REPAIR OR REPLACE HARNESS OR CONNECTOR

OK: Go to next step

PERFORM CONFIRMATION DRIVING PATTERN
NEXT: Go to next step

CHECK WHETHER DTC OUTPUT RECURS (DTC P2A00 AND/OR P2A03)

Read the DTCs using the Techstream.

Enter the following menus: Powertrain / Engine / Trouble Code / Pending.

Result

Display (DTC Output)	Proceed to
P2A00 and/or P2A03	A
No output	B

B → See step 11

A: Go to next step

REPLACE AIR FUEL RATIO SENSOR
1. Replace the air fuel ratio sensor. Refer to REMOVAL .
NEXT: Go to next step
PERFORM CONFIRMATION DRIVING PATTERN
NEXT: Go to next step

CHECK WHETHER DTC OUTPUT RECURS (DTC P2A00 AND/OR P2A03)

Read the DTCs using the Techstream.

Enter the following menus: Powertrain / Engine / Trouble Code / Pending.

Result

Display (DTC Output)	Proceed to
No output	A
P2A00 and/or P2A03	B

B → See step 12

A → END

GO TO DTC CHART. Refer to DIAGNOSTIC TROUBLE CODE CHART
REPLACE AIR FUEL RATIO SENSOR. Refer to REMOVAL
CHECK FOR INTERMITTENT PROBLEMS. Refer to CHECK FOR INTERMITTENT PROBLEMS
REPLACE ECM. Refer to REMOVAL