Dtc P2237 Oxygen (A/F) Sensor Pumping Current Circuit / Open (Bank 1 Sensor 1)

Lexus IS250 IS220d GSE20 ALE20 2AD-FHV ENGINE CONTROL SYSTEM

DESCRIPTION

MONITOR DESCRIPTION

WIRING DIAGRAM

INSPECTION PROCEDURE

CHECK OTHER DTC OUTPUT (IN ADDITION TO DTC P2237)

INSPECT AIR FUEL RATIO SENSOR (HEATER RESISTANCE)

INSPECT A/F RELAY

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

DTC P2237 Oxygen (A/F) Sensor Pumping Current Circuit / Open (Bank 1 Sensor 1)

DTC P2238 Oxygen (A/F) Sensor Pumping Current Circuit Low (Bank 1 Sensor 1)

DTC P2239 Oxygen (A/F) Sensor Pumping Current Circuit High (Bank 1 Sensor 1)

DTC P2252 Oxygen (A/F) Sensor Reference Ground Circuit Low (Bank 1 Sensor 1)

DTC P2253 Oxygen (A/F) Sensor Reference Ground Circuit High (Bank 1 Sensor 1)

DESCRIPTION

  • HINT:
For more information on the A/F sensor and TOYOTA D-CAT* .
This DTC is related to the A/F sensor, although the caption is the oxygen sensor.
If P2237, P2238 and/or P2239 is present, refer to the DTC table for TOYOTA D-CAT system .
These DTCs are recorded when A/F sensor has malfunction, although the caption is the oxygen sensor.
  • *: Diesel Clean Advanced Technology.

The A/F sensor has the characteristic of providing output voltage which is proportional to the existing air- fuel ratio. The A/F sensor output voltage (*1) is used to provide the ECM with feedback to control the air-fuel ratio.


The A/F sensor is located after the DPNR (*2) catalytic converter. This sensor has been developed based on structure and technology of a sensor that is being used for gasoline engines. The cover portion of the sensor has been changed for use in the diesel engine with TOYOTA D-CAT in order to eliminate the influence of the sensor temperature and particulate matter (PM).


In order to reduce both PM and nitrogen oxides (NOx), the ECM adjusts the air-fuel ratio to slightly RICH (but it is LEAN compared with a stoichiometric air-fuel ratio) based on signals from the A/F sensor. When the ECM exercises DPNR catalyst regeneration by adding fuel using the exhaust fuel addition injector, the air-fuel ratio is also properly adjusted through the sensor.


*1: The voltage value changes inside the ECM only.


*2: Diesel Particulate-NOx Reduction system.


Dtc P2237 Oxygen (A/F) Sensor Pumping Current Circuit / Open (Bank 1 Sensor 1). 2AD-FHV ENGINE CONTROL SYSTEM. Lexus IS250 IS220d GSE20 ALE20

  • HINT:
  • The ECM provides a pulse width modulated control circuit to adjust current through the heater. The A/F sensor heater circuit uses a relay on the B+ side of the circuit.

Dtc P2237 Oxygen (A/F) Sensor Pumping Current Circuit / Open (Bank 1 Sensor 1). 2AD-FHV ENGINE CONTROL SYSTEM. Lexus IS250 IS220d GSE20 ALE20

DTC No.DTC Detection ConditionTrouble Area
P2237 ECM internal error (5.0 seconds)
(1 trip detection logic)		 ECM
P2238
P2252		 A/F sensor circuit low (bank 1 sensor 1)
AF+ is less than 1.0 V for 5.0 seconds or more
(1 trip detection logic)
Open or short in A/F sensor circuit
A/F sensor
A/F sensor heater
A/F relay
A/F sensor heater and relay circuit
ECM
P2239
P2253		 A/F sensor circuit high (bank 1 sensor 1)
AF+ is more than 4.0 V for 5.0 seconds or more
(1 trip detection logic)
Open or short in A/F sensor circuit
A/F sensor
A/F sensor heater
A/F relay
A/F sensor heater and relay circuit
ECM

MONITOR DESCRIPTION

The A/F sensor varies its voltage output in proportion to the air-fuel ratio. If impedance (alternating current resistance) or voltage output of the sensor deviates greatly from the standard range, the ECM interprets this as an open or short in the A/F sensor circuit.


WIRING DIAGRAM

Dtc P2237 Oxygen (A/F) Sensor Pumping Current Circuit / Open (Bank 1 Sensor 1). 2AD-FHV ENGINE CONTROL SYSTEM. Lexus IS250 IS220d GSE20 ALE20

INSPECTION PROCEDURE

  • NOTICE:
  • After replacing the ECM, the new ECM needs registration and initialization .
1.CHECK OTHER DTC OUTPUT (IN ADDITION TO DTC P2237)

Connect the intelligent tester to the DLC3.

Turn the engine switch ON (IG) and turn the intelligent tester ON.

Enter the following menus: "Powertrain / Engine / DTC".

Read DTCs.

  • Result:
  • Display (DTC output)Proceed to
    P2237 and "P2238, P2239, P2252 and/or P2253"A
    P2237B
B
REPLACE ECM
A
2.INSPECT AIR FUEL RATIO SENSOR (HEATER RESISTANCE)
Dtc P2237 Oxygen (A/F) Sensor Pumping Current Circuit / Open (Bank 1 Sensor 1). 2AD-FHV ENGINE CONTROL SYSTEM. Lexus IS250 IS220d GSE20 ALE20

Disconnect the P35 A/F sensor connector.

Measure the resistance between the terminals of the A/F sensor.

  • Standard resistance:
  • Tester ConnectionConditionSpecified Condition
    +B (2) - HAF2 (1)20°C (68°F)1.8 to 3.4 Ω

Reconnect the A/F sensor connector.

NG
REPLACE AIR FUEL RATIO SENSOR
OK
3.INSPECT A/F RELAY
Dtc P2237 Oxygen (A/F) Sensor Pumping Current Circuit / Open (Bank 1 Sensor 1). 2AD-FHV ENGINE CONTROL SYSTEM. Lexus IS250 IS220d GSE20 ALE20

Remove the A/F relay.

Check for continuity in the A/F relay.

  • Standard resistance:
  • Tester ConnectionSpecified Condition
    3 - 510 kΩ or higher
    Below 1 Ω
    (Apply battery voltage to terminals 1 and 2)

Reinstall the A/F relay.

NG
REPLACE A/F RELAY
OK
4.CHECK HARNESS AND CONNECTOR (A/F SENSOR - ECM)
Dtc P2237 Oxygen (A/F) Sensor Pumping Current Circuit / Open (Bank 1 Sensor 1). 2AD-FHV ENGINE CONTROL SYSTEM. Lexus IS250 IS220d GSE20 ALE20

Disconnect the P35 A/F sensor connector.

Disconnect the E59 ECM connector.

Check the resistance between the wire harness side connectors.

  • Standard resistance (Check for open):
  • Tester ConnectionSpecified Condition
    AF2+ (P35-3) - AF2+ (E59-103)Below 1 Ω
    AF2- (P35-4) - AF2- (E59-126)Below 1 Ω
    HAF2 (P35-1) - HAF2 (E59-104)Below 1 Ω
  • Standard resistance (Check for short):
  • Tester ConnectionSpecified Condition
    AF2+ (P35-3) or AF2+ (E59-103) - Body ground10 kΩ or higher
    AF2- (P35-4) or AF2- (E59-126) - Body ground10 kΩ or higher
    HAF2 (P35-1) or HAF2 (E59-104) - Body ground10 kΩ or higher

Reconnect the A/F sensor connector.

Reconnect the ECM connector.

NG
REPAIR OR REPLACE HARNESS OR CONNECTOR
OK
REPLACE ECM