Isuzu 2008MY N Series Workshop Manual page 59

1A-56 Engine Control System (4HK1)
Step
Notice: If no airbag system installed, skip to Step
7.
6
Does the scan tool communicate SRS control
unit?
Notice: If no immobilizer system installed, skip to
Step 8.
7
Does the scan tool communicate SRS control
unit?
Test the Keyword serial data circuit for an
intermittently short to ground or intermittently short
to voltage. Then, test the Keyword serial data
circuit for an intermittently open (based on which
8
control module did not communicate) at the
connection in the circuit.
Did you find and correct the condition?
1. Inspect for an intermittent, for a poor
connection and for corrosion at the data link
connector (DLC) (pin 7 of B-31).
9
2. Repair the connection(s) as necessary.
Did you find and correct the condition?
1. Turn OFF the ignition.
2. Disconnect the ECM E-12 and J-14 harness
connectors.
3. Turn ON the ignition, with the engine OFF.
4. Attempt to communicate with the TCM, HSA
10
control unit and SRS control unit.
Does the scan tool communicate with the
TCM, ICU, HSA control unit and SRS control
unit?
Notice: If no Smoother transmission is installed,
skip to Step 12.
1. Turn OFF the ignition,
2. Reconnect the ECM E-12 and J-14 harness
connectors.
3. Disconnect the TCM B-109, B-110, B-111 and
B-112 harness connectors.
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4. Turn ON the ignition, with the engine OFF.
5. Attempt to communicate with the ECM, HSA
control unit and SRS control unit.
Does the scan tool communicate with the
ECM, ICU, HSA control unit and SRS control
unit?
Action Value(s) Yes
—
Go to Step 7
—
Go to Step 8
—
Go to Step 21
—
Go to Step 21
—
Go to Step 16
—
Go to Step 17
No
Go to Diagnostic
System Check -
SRS Controls in
Section 8C SRS
Control System
Go to Diagnostic
System Check -
Immobilizer
Controls in Section
9I Security and Lock
System OK
Go to Step 10
Go to Step 11
Go to Step 12