Pass your 310S, 310T, or 310J exam with less guesswork.

8 Topic areas

Sample notes

• Compression readings — Healthy gas engines run 130–180 psi and must be within ~10% across cylinders.
• CAN bus check — With the key off, CAN-H to CAN-L should read about 60 Ω (120 Ω terminator at each end).
• Fuel trims — Big positive LTFT at idle = vacuum leak. Big positive under load = fuel-delivery problem.

8 Topic areas

Sample notes

• Air brake basics — Typical governor range is roughly 100–125 psi cut-in / cut-out; low-pressure warning must activate by 60 psi.
• Diesel injection — Modern common-rail systems run 1,800–2,500 bar. Never crack a high-pressure line with the engine running.
• DPF regen — Active regen injects post-combustion fuel to burn soot — watch EGT and backpressure data during diagnosis.

Topic areas

Sample notes

• Air brake basics — Tractor protection valve trips ~40-60 psi to save tractor air if trailer separates.
• ABS — Trailer ABS power is typically pin 7 (blue wire) on the J560 connector.