Dtc P2228 Or P2229 (Flash Code 71) - Isuzu N 2008 Series Workshop Manual

DTC P2228 or P2229 (Flash Code 71)

Circuit Description
The barometric pressure (BARO) sensor is located
behind of the instrument panel (IP) bezel and fixed on
the crossbeam via bracket. The BARO sensor is a
transducer that varies voltage according to changes the
barometric pressure. The sensor has the following
circuits:
• 5 volts reference circuit
• Low reference circuit
• BARO sensor signal circuit
The BARO sensor provides a signal to the ECM on the
signal circuit, which is relative to the pressure changes
of the barometric pressure. The ECM should detect a
low signal voltage at a low barometric pressure, such
as high altitude place. The ECM should detect high
signal voltage at a high barometric pressure. The ECM
uses this voltage signal to calibrate the fuel injection
quantity and injection timing for altitude compensation.
If the ECM detects an excessively low or high signal
voltage, DTC P2228 or P2229 will set.
Condition for Running the DTC
• DTCs P060B and P0651 are not set.
• The battery voltage is between 18 to 32 volts
• The ignition switch is ON.
Circuit/ System Testing DTC P2228
Step
Did you perform the Diagnostic System Check -
1 Engine Controls?
1. Install a scan tool.
2. Turn OFF the ignition for 30 seconds.
3. Start the engine.
2
4. Monitor the DTC Information with a scan tool.
Is DTC P0651 also set?
Observe the Barometric Pressure (BARO) Sensor
parameter with a scan tool.
3
Is the BARO Sensor parameter less than the
specified value?
1. Turn OFF the ignition.
2. Disconnect
connector.
3. Connect a DMM between the 5 volts reference
4
circuit (pin 3 of B121) and a known good
ground.
4. Turn ON the ignition, with the engine OFF.
Is the DMM voltage more than the specified value?
Action
the BARO sensor harness
Engine Control System (4JJ1)
Condition for Setting the DTC
• The ECM detects that the BARO sensor signal
voltage is less than 0.5 volts for 5 seconds. (DTC
P2228)
• The ECM detects that the BARO sensor signal
voltage is more than 4.0 volts for 5 seconds. (DTC
P2229)
Action Taken When the DTC Sets
• The ECM illuminates the MIL when the diagnostic
runs and fails. Refer to DTC Type Definitions for
Action Taken When the DTC Sets - Type A.
• The ECM uses a BARO substitution of default
value.
• The ECM inhibits EGR control.
Condition for Clearing the DTC
• Refer to DTC Type Definitions for Condition for
Clearing the MIL/ DTC - Type A.
Diagnostic Aids
• If an intermittent condition is suspected, refer to
Intermittent Conditions in this section.
Connector End View Reference: Engine Controls
Connector End Views or ECM Connector End Views
Value(s) Yes
—
Go to Step 2
—
Go to DTC P0651
0.5 volts
Go to Step 4
4.5 volts
Go to Step 5
1A-259
No
Go to Diagnostic
System Check -
Engine Controls
Go to Step 3
Go to Diagnostic
Aids
Go to Step 6