Answer
Jun 06, 2025 - 03:43 PM
If you're not getting injector pulses on a 2005 Sorento diesel, you’re likely dealing with a control-side issue, meaning the ECU isn’t triggering the injectors, even though the engine is cranking. Here's what you should be looking at:
First thing to check is the crankshaft position sensor. If the ECU isn’t seeing a crank signal, it won’t trigger injection. No RPM signal = no pulse. Same goes for the camshaft sensor, depending on how the system is set up; some diesels need both signals to calculate timing.
Next, confirm that the ECU is actually powered up and grounded properly. Bad grounds, blown ECU fuses, or faulty relays (especially the main relay or fuel system relay) can all kill injector control.
Also worth checking is the immobilizer system. If there’s an issue with the key transponder or immobilizer module, the ECU might crank the engine but block fuel injection completely. A scan tool would help confirm if that’s the case, you'd usually get a security-related DTC.
Then, inspect the wiring harness between the ECU and injectors. Look for corrosion, damaged insulation, loose pins, or signs of rodents. You can also test each injector circuit with a noid light or scope while cranking.
Finally, if the crank/cam sensors are reading fine, power and grounds are good, and there's still no injector signal, then you may be looking at a faulty ECU itself — not super common, but not unheard of either, especially if there was a voltage spike, water ingress, or aftermarket wiring involved.
Start with scan data and crank signal confirmation. That usually tells you which direction to go.
