FAQ
TL;DR: In this Iveco 3.0 HPT case, 1/1 confirmed fix was a leaking vacuum line; "Problem solved by putting a new vacuum line to the PWM turbine solenoid." [Elektroda, zigfridsgusevs, post #19999149]
Why it matters: This FAQ helps Iveco 3.0 HPT owners diagnose injection cut-outs and warning lights without expensive guesswork.
Quick-Facts
- Symptom snapshot: injection light flashes ~3 seconds at ~80–90 km/h and power briefly cuts. [Elektroda, phupawelkulesza, post #16918956]
- Cold weather effect: issue worsened around −15°C, even at 60–80 km/h. [Elektroda, phupawelkulesza, post #17064498]
- Parts swapped before root cause found: regulator, filter, intake sensor, rail sensor, frame pump. [Elektroda, phupawelkulesza, post #17069131]
- Confirmed resolution in-thread: replace leaky vacuum line to PWM turbine solenoid. [Elektroda, zigfridsgusevs, post #19999149]
Quick Facts
- Symptom snapshot: injection light flashes ~3 seconds at ~80–90 km/h and power briefly cuts. [Elektroda, phupawelkulesza, post #16918956]
- Cold weather effect: issue worsened around −15°C, even at 60–80 km/h. [Elektroda, phupawelkulesza, post #17064498]
- Parts swapped before root cause found: regulator, filter, intake sensor, rail sensor, frame pump. [Elektroda, phupawelkulesza, post #17069131]
- Confirmed resolution in-thread: replace leaky vacuum line to PWM turbine solenoid. [Elektroda, zigfridsgusevs, post #19999149]
What do error codes 0085, 005c, and 000b point to here?
In this thread, group “85” was read as an EGR valve-related fault. That insight directed checks toward air and vacuum controls. The discussion focused on boost control and vacuum regulation rather than injectors alone. Treat these codes as starting points for diagnosis, not final proof. Verify live data and actuator control before replacing parts. “You have a problem with the fuel system,” one expert noted, tying pressure control and EGR/boost to the symptom. [Elektroda, Hart3, post #17066443]
How was the injection cut-out finally fixed in this case?
A member resolved it by replacing a leaking vacuum line feeding the PWM-controlled turbine (turbo) solenoid. The leak reduced boost control authority under load and triggered the injection warning with power loss. Quote: “Problem solved by putting a new vacuum line to the pwm turbine solenoid.” This single change ended the intermittent cut-outs after many part swaps. [Elektroda, zigfridsgusevs, post #19999149]
Why does the problem appear around 80–90 km/h under load?
At that speed, aerodynamic load and modest grades raise boost and fuel demands. The poster reported the injection light flashing for about three seconds with a brief power cut near 80–90 km/h. That pattern suggests control instability from vacuum or boost regulation, not constant fuel starvation. Checking the vacuum line and PWM turbo solenoid is warranted before deeper fuel system work. [Elektroda, phupawelkulesza, post #16918956]
Does cold weather make the symptom worse?
Yes. The owner noted significant worsening at about −15°C, with frequent flashing between 60–80 km/h. Cold can stiffen rubber lines and reveal minor vacuum leaks, aggravating boost control. Inspect brittle hoses and connections during winter conditions. Replace any hardened or cracked vacuum tubing and recheck driveability before replacing major components. [Elektroda, phupawelkulesza, post #17064498]
Which parts were replaced but didn’t cure it?
Documented replacements included: CR pump regulator, fuel filter, intake manifold sensor, common-rail pressure sensor, and the frame-mounted pump. Despite these, the fault persisted until the vacuum line fix. Statistic: at least five components were changed before the root cause was found. Prioritize testing over swapping to save time and cost. [Elektroda, phupawelkulesza, post #17069131]
Is the common-rail (CR) pump regulator the culprit here?
Not in this vehicle. The owner replaced the CR pump regulator with no improvement. That result shifts attention to control-side issues such as vacuum plumbing and the PWM turbo solenoid. Always corroborate with commanded versus actual rail pressure logs before calling a regulator bad. Replace only after confirming inability to track pressure targets under load. [Elektroda, phupawelkulesza, post #17068073]
What does the “PWM turbine solenoid” do on this Iveco?
It modulates vacuum to the turbo actuator using a PWM signal from the engine controller (EDC). That vacuum controls turbine vane or wastegate position, governing boost. A leak upstream of the solenoid reduces available vacuum, causing underboost and protective power cuts. “To regulate the vacuum is a PWM controlled valve with EDC,” a contributor explained. [Elektroda, Hart3, post #17071014]
What is the “pear” the owner mentions?
In this context, “pear” refers to the turbo’s vacuum actuator that moves with applied vacuum. If the lever does not rise at key-on, vacuum supply or control is suspect. Check the actuator for smooth travel and verify the vacuum line and PWM solenoid function. Restore proper vacuum before replacing actuators or turbos. [Elektroda, phupawelkulesza, post #17069131]
Quick 3-step: how do I check for the vacuum-line leak to the turbo solenoid?
- Inspect all vacuum hoses to the PWM turbine solenoid for cracks, loose fits, or oil-softened sections.
- Replace suspect hose with fresh vacuum line of correct diameter and secure with clamps.
- Road-test under load to confirm the injection light no longer flashes or cuts power.
“Problem solved by putting a new vacuum line...” [Elektroda, zigfridsgusevs, post #19999149]
What did “make a transfer inquiry” mean in the thread?
The member suggested checking fuel transfer/flow. The owner replied the “attempt made, good transfers,” indicating fuel delivery tests passed. That result de-emphasized the low-pressure fuel side and redirected attention to boost and vacuum control. Use flow checks to rule out supply issues before moving on. [Elektroda, phupawelkulesza, post #16996814]
Does replacing the frame-mounted pump help?
Not here. The frame pump was new and reported to work well, yet the symptom persisted. If a new pump does not change rail pressure stability or the flashing injection light, inspect control-side elements like vacuum lines, solenoid valves, and boost leaks. Avoid repeated pump swaps without data logs. [Elektroda, phupawelkulesza, post #17069131]
What’s the smartest order of diagnosis to avoid parts cannoning?
Start with code readout, then log boost and rail pressure versus targets under load. Smoke-test or visually check all vacuum lines and the PWM turbo solenoid before replacing hardware. An expert cautioned: “Look how many elements have been replaced, isn’t it easier to do a proper diagnosis.” Follow a test-first approach. [Elektroda, Hart3, post #17072984]
