Isuzu 2008MY N Series Workshop Manual page 188

Step
1. Test the signal circuit between the ECM (pin
73 of J-14) and the exhaust temperature
sensor 1 (pin 2 of J-34) for an open circuit or
high resistance.
8
2. Repair the circuit(s) as necessary.
Did you find and correct the condition?
Notice: The exhaust temperature sensor 1 shares
the low reference circuit with other sensors. A fault
condition in the low reference circuit may set DTCs
on sensors that share this circuit.
1. Test the low reference circuit between the
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ECM (pin 79 of J-14) and the exhaust
temperature sensor 1 (pin 1 of J-34) 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
73 of J-14) and the exhaust temperature
sensor 1 (pin 2 of J-34) for a short to any 5
volts reference circuit.
10
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
exhaust temperature sensor 1 (pins 1 and 2 of
J-34).
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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 73 and 79 of J-14).
4. Repair the connection(s) as necessary.
Did you find and correct the condition?
Replace the exhaust temperature sensor 1. Refer
to Exhaust Temperature Sensor in Section 1G
13
Engine Exhaust.
Did you complete the replacement?
Important: Replacement
programmed and learned.
14
Replace the ECM. Refer to ECM Replacement.
Did you complete the replacement?
Action
ECM must
Engine Control System (4HK1)
Value(s)
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be
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Yes
Go to Step 15 Go to Step 12
Go to Step 15 Go to Step 12
Go to Step 15 Go to Step 11
Go to Step 15 Go to Step 13
Go to Step 15 Go to Step 14
Go to Step 15
Go to Step 15
1A-185
No
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