DTC P2231
Diagnostic Instructions
DTC Descriptor
| DTC P2231 00: HO2S Signal Circuit Shorted to
Heater Circuit Sensor 1 |
Diagnostic Fault Information
Circuit
|
Short to Ground
|
Open/High Resistance
|
Short to Voltage
|
Signal Performance
|
Heater Voltage Supply
|
P0030 00
|
P0030 00
|
-
|
P0131 5A, P0131 12
|
Reference Voltage (Signal)
|
P0131 01
|
P0131 12, P2243 00, P2231 00
|
P0131 02, P2231 00
|
P0133 00, P0131 52, P0131 5A, P0132 52, P0132 5B
|
Pump Current Signal
|
P2626 00
|
P2626 00
|
P2626 00, P2231 00
|
-
|
Trim Current Signal
|
P2626 00
|
P2626 00
|
P2626 00
|
-
|
Heater Low Control
|
P0031 00
|
P0030 00
|
P0032 00
|
-
|
Low Reference (Ground)
|
P2A00 00
|
P0132 02, P2243 04
|
P0132 02
|
-
|
|
| |
Circuit/System Description
The wide band heated oxygen sensor (HO2S) measures the amount of
oxygen in the exhaust stream more quickly and accurately than the
switching style HO2S. The wide band sensor consists of an oxygen
sensing cell, an oxygen pumping cell, and a heater. The exhaust gas
sample passes through a diffusion gap between the sensing cell and
the pumping cell. The engine control module (ECM) supplies a signal
voltage to the HO2S and uses this voltage as a reference to the
amount of oxygen in the exhaust system. An electronic circuit
within the ECM controls the pump current through the oxygen pumping
cell in order to maintain a constant signal voltage. The ECM
monitors the voltage variation on the signal circuit and attempts
to keep the voltage constant by increasing or decreasing the amount
of current flow or reversing the direction of the current flow to
the pumping cell. By measuring the direction and amount of current
required to maintain the signal voltage, the ECM can determine the
concentration of oxygen in the exhaust. The signal voltage is
displayed as a lambda value. A lambda value of 1 is equal to a
stoichiometric air fuel ratio of 60:1. Under normal operating
conditions, the lambda value will remain around 1. When the system
is lean, the oxygen level will be high and the lambda value will be
high, or more than 1. When the system is rich, the oxygen level is
low and the lambda value will be low, or less than 1. The ECM uses
this information to maintain the proper air/fuel ratio.
Conditions for Running the DTC
| • |
The ignition voltage is
between 10-18 V. |
| • |
The engine speed is greater
than 80 RPM. |
| • |
The HO2S 1 heater is at
operating temperature. |
| • |
DTC P2231 runs continuously
when the above conditions are met. |
Conditions for Setting the DTC
| • |
The ECM detects that the HO2S
1 voltage is more than the threshold. |
| • |
DTC P2231 sets within 4 s when
the above condition is met continuously, or within 50 s when the
above condition is met cumulatively. |
Action Taken When the DTC Sets
DTC P2231 is a Type B DTC.
Conditions for Clearing the DTC
DTC P2231 is a Type B DTC.
Reference Information
Schematic Reference
Engine Controls Schematics
Connector End View Reference
Component Connector End Views
Electrical Information Reference
DTC Type Reference
Powertrain Diagnostic Trouble Code (DTC) Type Definitions
Scan Tool Reference
Control Module References for scan tool information
Circuit/System Verification
| 1. |
Clear the DTCs with a scan
tool. |
| 2. |
Operate the vehicle within the
conditions for running and setting the DTC. The DTC should not
set. |
| 3. |
Operate the vehicle within the
Conditions for Running the DTC. You may also operate the vehicle
within the conditions that you observed from the Freeze
Frame/Failure Records data. |
Circuit/System Testing
Note: You must perform the
Circuit/System Verification before proceeding with Circuit/System
Testing.
| 1. |
Ignition OFF, disconnect the
harness connector at the B52A Heated Oxygen Sensor 1. |
| 2. |
Ignition ON, test for 2.9 V
between the B52A Heated Oxygen Sensor 1 reference voltage circuit
terminal 6 and ground. |
| ⇒ |
If less than the specified range, test the
reference voltage circuit for a short to ground or an open/high
resistance. If the circuit tests normal, replace the K20 Engine
Control Module. |
| ⇒ |
If greater than the specified range, test the
reference voltage circuit for a short to voltage. If the circuit
tests normal, replace the K20 Engine Control Module. |
| 3. |
Test for 2.5 V between the
B52A Heated Oxygen Sensor 1 low reference circuit terminal 2 and
ground. |
| ⇒ |
If less than the specified range, test the low
reference circuit for a short to ground or an open/high resistance.
If the circuit tests normal, replace the K20 Engine Control
Module. |
| ⇒ |
If greater than the specified range, test the low
reference circuit for a short to voltage. If the circuit tests
normal, replace the K20 Engine Control Module. |
| 4. |
Test for 2.8 V between the
B52A Heated Oxygen Sensor 1 control circuit terminal 1 and
ground. |
| ⇒ |
If less than the specified range, test the control
circuit for a short to ground or an open/high resistance. If the
circuit tests normal, replace the K20 Engine Control Module. |
| ⇒ |
If greater than the specified range, test the
control circuit for a short to voltage. If the circuit tests
normal, replace the K20 Engine Control Module. |
| 5. |
Test for 2.8 V between the
B52A Heated Oxygen Sensor 1 control circuit terminal 5 and
ground. |
| ⇒ |
If less than the specified range, test the control
circuit for a short to ground or an open/high resistance. If the
circuit tests normal, replace the K20 Engine Control Module. |
| ⇒ |
If greater than the specified range, test the
control circuit for a short to voltage. If the circuit tests
normal, replace the K20 Engine Control Module. |
| 6. |
Ignition OFF, disconnect the
X1 harness connector at the K20 Engine Control Module. |
| 7. |
Test for infinite resistance
between each B52A Heated Oxygen Sensor 1 circuit terminals.
|
| ⇒ |
If less than the specified value, repair as
necessary. |
| 8. |
If all circuits test normal,
replace the B52A Heated Oxygen Sensor 1 and verify the DTC does not
reset. |
| ⇒ |
If the DTC resets, replace the K20 Engine Control
Module. |
Repair Instructions
Perform the
Diagnostic Repair Verification after completing the diagnostic
procedure.
|
