Isuzu N 2008 Series Workshop Manual page 315

1A-312 Engine Control System (4JJ1)
Step
Repair the open circuit or high resistance between
the ECM Main (10A) fuse and the solenoid valve
22
(pin 1 of J26).
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 the following conditions:
• An open circuit
23
• A short to battery or ignition voltage
• High resistance
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.
24
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).
25
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 the harness connector of the
26
ECM (pin 15 of J14).
4. Repair the connection(s) as necessary.
Did you find and correct the condition?
Replace the exhaust brake solenoid valve.
27
Did you complete the replacement?
Important:
programmed and learned.
28
Replace the ECM. Refer to ECM Replacement.
Did you complete the replacement?
Reconnect
components, fuse or harness connector(s).
29
Did you complete the action?
Circuit/ System Testing Exhaust Brake Control System Check (2 of 2)
Step
1. Install a scan tool.
2. Turn ON the ignition, with the engine OFF.
3. Apply the exhaust brake switch ON and OFF
while observing the Exhaust Brake Switch
1
parameter with a scan tool.
Does the scan tool indicate ON and OFF with each
switch transition?
Action
Replacement ECM
all previously disconnected
Action
Value(s)
—
—
—
—
—
—
must be
—
—
Value(s)
—
Yes
Go to Step 29
Go to Step 29 Go to Step 26
Go to Step 29
Go to Step 29 Go to Step 27
Go to Step 29 Go to Step 28
Go to Step 29
Go to Step 29
Go to Step 3
Yes
Go to Step 2 Go to Step 3
No
—
—
—
—
—
No