Isuzu N 2008 Series Workshop Manual page 154

Step
1. Test the control circuit between the ECM (pin
10 of J14) and the relay (pin 5 of X19) for the
following conditions:
• An open circuit
• A short to ground
5
• A short to battery or ignition voltage
• High resistance
2. Repair the circuit(s) as necessary.
Did you find and correct the condition?
Repair the open circuit or high resistance between
the ECM (10A) fuse and the glow relay coil side
6
(pin 3 of X19). Check the ECM (10A) fuse first.
Did you complete the repair?
1. Remove the glow relay.
2. Inspect for an intermittent and for a poor
connection on each relay terminal.
7
3. 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
8
ECM (pin 10 of J14).
4. Repair the connection(s) as necessary.
Did you find and correct the condition?
Replace the glow relay.
9
Did you complete the replacement?
Important: Replacement
programmed and learned.
10
Replace the ECM. Refer to ECM Replacement.
Did you complete the replacement?
1. Reconnect all previously disconnected fuse,
relay or harness connector(s).
2. Clear the DTCs with a scan tool.
3. Perform the Glow Relay Control with a scan
11
tool.
4. Command the relay ON and OFF.
Does the glow relay click with each command?
Observe the DTC Information with a scan tool.
12
Are there any DTCs that you have not diagnosed?
Action
ECM must
Engine Control System (4JJ1)
Value(s)
—
—
—
—
—
be
—
—
—
Yes
Go to Step 11 Go to Step 8
Go to Step 11
Go to Step 11 Go to Step 9
Go to Step 11 Go to Step 10
Go to Step 11
Go to Step 11
Go to Step 12 Go to Step 3
Go to DTC List
1A-151
No
—
—
—
System OK