Isuzu N 2008 Series Workshop Manual page 182

Step
Does the test lamp remain illuminated with each
5
command?
Repair the open circuit or high resistance between
the ECM Main (10A) fuse and the solenoid valve
6
(pin 1 of J26). Check the ECM Main (10A) fuse first.
Did you complete the repair?
1. Test the control circuit between the ECM (pin
15 of J14) and the solenoid valve (pin 2 of
J26) for an open circuit or high resistance.
7
2. Repair the circuit(s) as necessary.
Did you find and correct the condition?
1. Test the control circuit between the ECM (pin
15 of J14) and the solenoid valve (pin 2 of
J26) for a short to ground.
8
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
solenoid valve (pins 1 and 2 of J26).
9
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 a poor
connection at harness connector of the ECM
10
(pin 15 of J14).
4. Repair the connection(s) as necessary.
Did you find and correct the condition?
Replace the exhaust brake solenoid valve.
11
Did you complete the replacement?
Important: Replacement
programmed and learned.
12
Replace the ECM. Refer to ECM Replacement.
Did you complete the replacement?
1. Reconnect all previously disconnected fuse or
harness connector(s).
2. Clear the DTCs with a scan tool.
3. Perform the Exhaust Brake Control with a
13
scan tool.
4. Command the solenoid valve ON and OFF.
Does the solenoid valve click with each command?
Observe the DTC Information with a scan tool.
14
Are there any DTCs that you have not diagnosed?
Action
ECM must
Engine Control System (4JJ1)
Value(s)
—
—
—
—
—
—
—
be
—
—
—
Yes
Go to Step 8 Go to Step 7
Go to Step 13
Go to Step 13 Go to Step 10
Go to Step 13 Go to Step 12
Go to Step 13 Go to Step 11
Go to Step 13 Go to Step 12
Go to Step 13
Go to Step 13
Go to Step 14 Go to Step 3
Go to DTC List
1A-179
No
—
—
—
System OK