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Home >> Isuzu >> 2007 >> i-290 LS, Standard >> Repair and Diagnosis >> External Pages >> Different car >> Section 86 (Engine Control System & Fuel System - 3.7L - Diagnosis & Troubleshooting) >> Fuel Injector Circuit Diagnosis >> Diagnostic Aids

Diagnostic Aids

WARNING: This page is about a different car, the 2007 Isuzu i-370, 2007 GMC Canyon, and 2007 Chevrolet Colorado. However, it is still accessible from the selected car via links, so may be relevant.
Fuel Injector Circuit Diagnosis

Step Action Yes No
Schematic Reference: Engine Controls Schematics
Connector End View Reference: Powertrain Control Module Connector End Views or Engine Controls Connector End Views
1 Did you perform the Diagnostic System Check - Vehicle? Go to Step 2  Go to Diagnostic System Check - Vehicle
2 Is DTC P0201, P0202, P0203, P0204, or P0205 set? Go to DTC P0201, P0202, P0203, P0204, or P0205 Go to Step 3 
3 Inspect the Injectors fuse.
Is the fuse open?
Go to Step 4  Go to Step 6 
4
  1. Turn OFF the ignition.
  2. Disconnect the multi-way harness connector of the fuel injectors.
  3. Probe the ignition 1 voltage circuit of the fuel injector, fuse side, with a test lamp that is connected to battery voltage. Refer to Probing Electrical Connectors .
Does the test lamp illuminate?
Go to Step 9  Go to Step 5 
5 Turn ON the ignition, with the engine OFF.
Does the test lamp illuminate?
Go to Step 13  Go to Step 8 
6
  1. Turn OFF the ignition.
  2. Disconnect the multi-way harness connector of the fuel injectors.
  3. Turn ON the ignition, with the engine OFF.
  4. Probe the ignition 1 voltage circuit of the fuel injector, fuse side, with a test lamp that is connected to a good ground. Refer to Probing Electrical Connectors .
Does the test lamp illuminate?
Go to Step 7  Go to Step 10 
7 Test for continuity between the ignition 1 voltage circuit terminal and a fuel injector terminal, at the multi-way harness connector, fuel injector side. Refer to Testing for Continuity .
Does the DMM display OL?
Go to Step 11  Go to Step 12 
8 Test the ignition 1 voltage circuit of the fuel injector, between the multi-way harness connector and the fuel injectors for a short to ground. Refer to Circuit Testing and Wiring Repairs .
Did you find and correct the condition?
Go to Step 14  Go to Intermittent Conditions 
9 Repair the short to ground in the ignition 1 voltage circuit of the fuel injector. Refer to Wiring Repairs .
Did you complete the repair?
Go to Step 14  -
10 Repair the open in the ignition 1 voltage circuit between the PCM 1 fuse and the multi-way connector. Refer to Wiring Repairs .
Did you complete the repair?
Go to Step 14  -
11 Repair the open or high resistance in the ignition 1 voltage circuit of the fuel injectors between the multi-way connector and the splice. Refer to Wiring Repairs .
Did you complete the repair?
Go to Step 14  -
12 Repair the poor connection at the multi-way harness connector. Refer to Connector Repairs .
Did you complete the repair?
Go to Step 14  -
13 Repair the short to a PCM ground in the ignition 1 voltage circuit of the fuel injector. Refer to Wiring Repairs .
Did you complete the repair?
Go to Step 14  -
14 Operate the system in order to verify the repair.
Did you correct the condition?
System OK Go to Step 3