Vehicle: 2006 Dodge Durango, 2WD, V6-3.7L, VIN K, Automatic Transmission/Transaxle
Problem: This vehicle was towed in because the engine would crank over but not start.
Case Details: First, the technician checked for spark and fuel pressure. The spark was strong; the fuel pressure was within specifications. Next, he checked fuses and the ASD relay. All the fuses were good and the ASD relay was working properly. He then connected a noid light to check injector pulse. There was none.
He connected a scan tool next to expand the diagnostic testing. The scan tool showed that the engine cranking speed was 223 RPM so the crankshaft position sensor was working properly. The technician also noted that there were no diagnostic trouble codes (DTCs). A quick call to ALLDATA Tech-Assist provided some additional testing.
The Tech-Assist consultant suggested testing for battery voltage at the fuel injector’s red wires and to test for a pulsed ground on the other wire at each injector. Since the coils and injectors share the same power source, if there is a spark, there should be no issue with injector power unless there is a bad injector ground wire or power wire.
The consultant further advised that if there was no ground pulse at the injectors, the technician should check the powertrain control module (PCM) grounds before condemning the PCM.
The tech found battery voltage at each injector but no ground pulse. While inspecting the PCM, the technician found that the PCM ground point (G100) was heavily corroded. All seven wires attached at that one ground point either had poor or no ground.
The technician cleaned the ground point, repaired the corroded wires, and replaced the ground connector. After the repairs, the engine started and ran normally. Fixed!