Hombre XS Space Cab L4-2.2L CPC (1997)
1. The Powertrain OBD System Check prompts the technician to complete some basic checks and stores the freeze frame and failure records data on
the scan tool, if applicable. This creates an electronic copy of the data taken when the malfunction occurred. The information is then stored in the
scan tool for later reference.
2. If the no start condition was due to a open fuse, locate and repair any shorts that may have caused the fuse to open before replacement.
3. This step determines if the fuel pump circuit can be controlled by the PCM. The PCM should energize the fuel pump relay and turn the fuel pump
ON when commanded by the scan tool. If the engine is not cranking or running, the PCM should de-energize the relay and turn OFF the fuel pump
after 2-3 seconds.
4. Jumpering the fuel pump relay injector/fuel pump feed circuit to fuel pump battery feed circuit verifies that the fuel pump relay ignition
feed circuit, the fuel pump feed circuit, the fuel pump and fuel ground are all OK.
7. Check for an open fuel pump relay ground.
16. Replacement PCMs must be reprogrammed and the crankshaft position system variation procedure must be performed. Refer to the latest Isuzu
Technical Communication System (ITCS) information for programming procedures and also refer to the CKP System Variation Learn Procedure.
17. This step checks the fuel pump ground circuit on the body side of the body harness only. If the fuel pump ground circuit is OK, then the
fuel pump relay injector/fuel pump feed circuit or the fuel pump ground circuit in the fuel tank harness or the fuel pump itself is malfunctioning.
20. This test will determine if a short to ground on the fuel pump relay injector/fuel pump feed circuit caused the fuse to open. To prevent
mis-diagnosis, be sure the fuel pump harness is disconnected before the test.
