A no-start condition in a diesel engine can be incredibly frustrating, especially when dealing with the complexities of the 6.0 Powerstroke. This engine, known for its power but also its quirks, often leaves owners and mechanics scratching their heads when it refuses to fire up. This case study dives into a recent diagnostic journey on a 2006 Ford F350 with a 6.0 Powerstroke engine experiencing a crank no start issue. Having extensive experience with the 7.3 Powerstroke, but less so with the 6.0, we approached this challenge methodically, documenting each step to pinpoint the root cause.
Initial Problem and Background
The vehicle in question, a 2006 Ford F350 with 268,000 miles, presented with a straightforward symptom: it would crank vigorously but fail to start. The backstory indicated the truck had been running without issue before suddenly dying and refusing to restart. Prior attempts to resolve the problem involved replacing several key components, including the batteries, high-pressure oil pump (HPOP), injection pressure regulator (IPR), and injection pressure control (IPC) sensor. Despite these replacements, the no-start condition persisted, and the truck sat idle for over a year before landing in our workshop for a fresh diagnosis.
Diagnostic Steps and Initial Findings
Our initial inspection began with a thorough check of the engine wiring, focusing on potential damage, particularly from rodents. The only notable finding was broken connector tabs on the Fuel Injection Control Module (FICM) connectors, though the connections themselves seemed secure. After ensuring proper battery charge and conducting battery tests, we connected a scan tool to gather live data during cranking. The readings were as follows:
- EBP (Exhaust Back Pressure): 14.5 psi
- RPM: 171.8
- HPOP (High-Pressure Oil Pump): 1312.7 psi
- Battery Voltage: 10.5V (starting from 12.1V)
- IPR (Injection Pressure Regulator): 40.2%
- ICP (Injection Control Pressure) Voltage: 1.5V
- FPV (FICM Power Voltage): 10.5V (starting from 12.0V)
- FLP (FICM Logic Power): 10.0V (starting from 12.0V)
- FMP (FICM Main Power): 47.5V
- SYNC: 1 (indicating crankshaft and camshaft synchronization)
These initial readings appeared within acceptable ranges, suggesting the HPOP was generating sufficient pressure and the engine was cranking properly. However, fault codes were present for the trailer brake controller (TBC), glow plug module, and open/short circuits on all eight glow plugs. Crucially, there were no codes directly related to the engine’s inability to start.
To rule out fuel delivery issues, we checked for fuel flow by removing the secondary fuel filter and observing the filter housing while cycling the ignition. The housing filled rapidly, indicating adequate fuel supply to the engine. While a fuel pressure test wasn’t performed due to lack of specialized tools on hand, the rapid fill suggested fuel starvation was unlikely. Voltage checks at the FICM with a multimeter confirmed proper power delivery to the module.
Alt text: Location of the fuel filter housing on a 6.0 Powerstroke engine, a common point to check for fuel delivery issues during crank no start diagnosis.
Injector Buzz Test and FICM Suspicions
A key observation during initial diagnosis was the absence of the characteristic “buzz test” sound from the injectors when the ignition was turned on. In 7.3 Powerstroke engines, this buzz is a clear indicator of injector functionality during key-on. The only audible sound was a humming from the fuel filter area, presumed to be the fuel pump, and occasional vacuum pump operation. An electrical self-test using FORScan (Ford Scan Tool) in Key On Engine Off (KOEO) mode passed, but again, no injector buzz was detected.
To further investigate, a KOEO self-test was conducted using FORScan, which also passed. However, the lack of injector buzz during this test, compared to the audible buzz expected in similar tests on 7.3 Powerstroke engines, raised suspicions about the FICM’s functionality. The absence of injector noise during both key-on and the FORScan self-test was a significant deviation from expected behavior.
Desperate for a sign of life, a shot of starter fluid was administered. The engine fired up and ran briefly on the starter fluid, confirming mechanical engine integrity and highlighting a likely fuel or injection system problem. This test strongly suggested the issue was not compression or timing related, but rather centered around fuel delivery or injector operation.
Parts Replacement and Continued No Start
Based on the accumulated evidence, particularly the lack of injector buzz and the engine firing with starter fluid, the FICM was identified as a prime suspect. Considering the owner’s budget constraints and desire to sell the truck, a decision was made to replace several potentially problematic components: the glow plug relay, injector wiring harness, FICM connector on the main harness, and the FICM itself. The FICM was sourced from a reputable online vendor specializing in automotive computers, and the remaining parts were obtained through standard channels.
Alt text: Close-up view of the Fuel Injection Control Module (FICM) on a 6.0 Powerstroke engine, a critical component in injector operation and a common suspect in crank no start scenarios.
The glow plug relay, injector harness, and FICM connector were replaced first. After clearing codes and attempting to start the engine, the no-start condition persisted unchanged. Diagnostic tests were rerun, revealing the same open/short codes for all eight glow plugs, but the glow plug relay code did not return. Cranking parameters were monitored again, yielding virtually identical readings to the initial diagnosis.
Subsequently, the FICM itself was replaced. With fully charged batteries, another start attempt was made, but the truck remained stubbornly in a crank no start state. Post-FICM replacement diagnostics revealed a P0611 code (FICM performance) along with the recurring glow plug codes. After clearing codes and retesting, only the glow plug codes reappeared.
Repeating the sensor monitoring during cranking after FICM replacement produced the following readings:
- EBP: 14.4 psi
- RPM: 177.0
- HPOP: 1411.3 psi
- Battery Voltage: 11.7V (starting from 13.0V)
- IPR: 40.6%
- ICP Voltage: 1.6V
- FPV: 10.0V (starting from 13.0V)
- FLP: 10.5V (starting from 13.0V)
- FMP: (Value missing in original log, assumed similar to previous)
- SYNC: 1
These readings remained consistent even after FICM replacement, and crucially, the lack of injector buzz during key-on and KOEO tests persisted. The engine still only runs with starter fluid, pointing firmly towards a persistent fuel or injection control issue despite replacing numerous components.
Conclusion and Next Steps
Despite replacing the HPOP, IPR, IPC, FICM, and related wiring components, the 2006 F350 6.0 Powerstroke continues to exhibit a crank no start condition. The consistent readings during cranking, coupled with the engine firing on starter fluid, suggest the core issue lies within the fuel injection system’s electrical control or potentially a deeper, yet undiagnosed, sensor or wiring problem. The persistent lack of injector buzz remains a critical clue. Further investigation should focus on:
- Verifying FICM power and ground circuits under load: While static voltage checks were performed, dynamic testing during cranking is essential to rule out voltage drops or intermittent connections.
- Detailed injector circuit testing: Pinpointing whether the issue is a lack of signal from the FICM to the injectors, or a problem within the injector circuits themselves.
- Crankshaft Position Sensor and Camshaft Position Sensor integrity: Although SYNC is indicated, a deeper dive into the signal quality from these sensors is warranted.
- ECM (Engine Control Module) diagnostics: While less likely given the replaced components, ECM malfunction cannot be entirely ruled out.
This 6.0 Powerstroke Crank No Start Diagnosis case highlights the complexities of modern diesel engine troubleshooting. Systematic elimination, data-driven diagnostics, and a persistent approach are crucial to unraveling even the most stubborn no-start mysteries. The journey continues, and further investigation is needed to finally bring this F350 back to life.
