EC-1488< SERVICE INFOMATION >
[MR TYPE 2]
DTC P2A00 A/F SENSOR 1
DTC P2A00 A/F SENSOR 1
Component Description INFOID:0000000004501225
The air fuel ratio (A/F) sensor 1 is a planar one-cell limit current sen-
sor. The sensor element of the A/F sensor 1 is composed an elec-
trode layer, which transports ions. It has a heater in the element.
The sensor is capable of precise measurement = 1, but also in the
lean and rich range. Together with its control electronics, the sensor
outputs a clear, continuous signal throughout a wide range.
The exhaust gas components diffuse through the diffusion layer at
the sensor cell. An electrode layer is applied voltage, and this current
relative oxygen density in lean. Also this current relative hydrocar-
bon density in rich.
Therefore, the A/F sensor 1 is able to indicate air fuel ratio by this
electrode layer of current. In addition, a heater is integrated in the
sensor to ensure the required operating temperature of about 800 °C
(1,472 °F).
CONSULT-III Reference Value in Data Monitor Mode INFOID:0000000004501226
Specification data are reference values.
On Board Diagn osis Logic INFOID:0000000004500393
To judge the malfunction, the A/F signal computed by ECM from the A/F sensor 1 signal is monitored not to be
shifted to LEAN side or RICH side.
DTC Confirmation Procedure INFOID:0000000004500394
NOTE:
If DTC Confirmation Procedure has been previously conduc ted, always turn ignition switch OFF and wait at
least 10 seconds before conducting the next test.
TESTING CONDITION:
Before performing the following procedure, confirm that battery voltage is more than 11V at idle.
WITH CONSULT-III
1. Start engine and warm it up to normal operating temperature.
2. Turn ignition switch OFF and wait at least 10 seconds. PBIB3353E
PBIB3354E
MONITOR ITEM CONDITION SPECIFICATION
A/F SEN1 (B1) • Engine: After warming up Maintaining engine speed at
2,000 rpm Fluctuates around 2.2VDTC No. Trouble diagnosis name DTC detecting condition Possible Cause
P2A00
2A00 Air fuel ratio (A/F) sensor 1
circuit range/performance • The output voltage computed by ECM from the
A/F sensor 1 signal is shifted to the lean side for
a specified period.
• The A/F signal computed by ECM from the A/F
sensor 1 signal is shifted to the rich side for a
specified period. • Air fuel ratio (A/F) sensor 1
• Air fuel ratio (A/F) sensor 1 heater
• Fuel pressure
• Fuel injector
• Intake air leaks