Isuzu 2008MY N Series Workshop Manual page 107

1A-104 Engine Control System (4HK1)
Step
Connect a 3-amp fused jumper wire between the 5
volts reference circuit and the signal circuit (pins 1
and 3 of E-24).
5
Is the Boost Pressure Sensor parameter more
than the specified value?
Notice: The boost pressure sensor shares the 5
volts reference circuit with other sensors. A fault
condition in the 5 volts reference circuit may set
DTCs on sensors that share this circuit.
1. Test the 5 volts reference circuit between the
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ECM (pin 95 of E-12) and the boost pressure
sensor (pin 3 of E-24) for an open circuit or
high resistance.
2. Repair the circuit(s) as necessary.
Did you find and correct the condition?
1. Test the signal circuit between the ECM (pin
91 of E-12) and the boost pressure sensor
(pin 1 of E-24) for the following conditions:
• An open circuit
• A short to ground
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• A short to the low reference circuit
• High resistance
2. Repair the circuit(s) as necessary.
Did you find and correct the condition?
1. Inspect for an intermittent and for poor
connections at the harness connector of the
boost pressure sensor (pins 1 and 3 of E-24).
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2. Repair the connection(s) as necessary.
Did you find and correct the condition?
1. Turn OFF the ignition.
2. Disconnect the ECM harness connector.
3. Inspect for an intermittent and for poor
connections at the harness connector of the
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ECM (pins 91 and 95 of E-12).
4. Repair the connection(s) as necessary.
Did you find and correct the condition?
Replace the boost pressure sensor. Refer to Boost
Pressure Sensor in Section 1J Induction.
10
Did you complete the replacement?
Important:
programmed and learned.
11
Replace the ECM. Refer to ECM Replacement.
Did you complete the replacement?
Action
Replacement ECM
Value(s)
4.5 volts
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must be
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Yes
Go to Step 8 Go to Step 7
Go to Step 12 Go to Step 9
Go to Step 12 Go to Step 9
Go to Step 12 Go to Step 10
Go to Step 12 Go to Step 11
Go to Step 12
Go to Step 12
No
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