Isuzu 20LE - Rough, Unstable, or Incorrect Idle, Stalling Sympton (for Closed Loop System)

6E1-92 DRIVEABILITY AND EMISSIONS
Rough, Unstable, or incorrect Idle, Stalling Sympton (For Closed Loop System)
Step Action Value(s) Yes No
1
Was the “On-Board Diagnostic (OBD) System Check”
performed? -
Go to Step 2
Go to OBD
System
Check
2
1. Read the “Caution” above.
2. Relieve the fuel system pressure and install the fuel
pump pressure gauge to the test fitting.
3. Use a scan tool to command the fuel pump ON.
Is there an immediate pressure build-up which indicates
the pump is running?
-
Go to Step 3 Go to Step 4
3
1. Verify that the pump is not running by removing the
fuel filler cap and listening.
2. Command the pump ON with the scan tool.
Did the pump turn OFF after 2 seconds?
-
Test
completed Go to Step 12
4
1. Ignition OFF.
2. Remove the fuel pump relay.
3. Using a test light connected to ground, probe the
battery feed to the relay.
Did the light illuminate?
-
Go to Step 6 Go to Step 5
5
Repair short or open battery feed to fuel pump relay.
Is the action complete?
-
Verify repair
-
6
1. Connect a test light between the two wires that
connect to the fuel pump relay pull-in coil.
2. Ignition ON.
Did the test light illuminate for 2 seconds and then turn
off?
-
Go to Step 12 Go to Step 7
7
1. With a test light connected to battery (-), probe the fuel
pump relay connector at the wire which runs from the
relay pull-in coil to the ECM.
2. Ignition ON.
Did the test light illuminate for 2 seconds and then turn
off?
-
Go to Step 8 Go to Step 9
8
Locate and repair open in the fuel pump relay ground
circuit.
Is the action complete?
-
Verify repair
-
9
Check for short or open between the ECM and the fuel
pump relay.
Was a problem found?
-
Verify repair Go to Step 10
10
1. Check the fuel pump relay circuit for a poor terminal
connection at the ECM.
2. If a problem is found, replace terminal as necessary.
Was a problem found?
-
Verify repair Go to Step 11
11
Replace the ECM.
Important: The replacement ECM must be programmed.
Refer to On-Vehicle Service in Powertrain Control Module
and Sensors for procedures.
Is the action complete?
-
Verify repair
-