Systematic diagnostic approach for complete loss of drive or reverse in JF015E CVT transmissions.
A vehicle with no drive or reverse can unexpectedly move. Always use wheel chocks, work on level ground, and never work under a vehicle supported only by a jack.
Complete loss of drive or reverse is a serious transmission issue that prevents vehicle operation. The JF015E uses a forward clutch assembly and reverse brake band to provide directional control. When these components or their hydraulic systems fail, the transmission cannot transfer power to the wheels.
Before diving into complex diagnostics, always verify these simple issues that can mimic transmission failure:
Verify parking brake is fully released. Sticking parking brake can prevent movement.
Check that selector is actually moving the transmission lever. Broken linkage gives the appearance of transmission failure.
Extremely low fluid (from major leak) can cause complete loss of hydraulic function.
Verify driveshafts are connected. Transmission may function but vehicle won't move.
Connect scan tool and retrieve all TCM fault codes. Common codes include P0868 (pressure low), P0841 (pressure sensor), or P0734-P0736 (gear ratio errors).
Using scan tool live data, monitor line pressure in Drive and Reverse. Should be 35-45 bar minimum.
If Pressure Normal ➜
Mechanical failure (clutch/brake)
If Pressure Low ➜
Hydraulic issue (pump/valve body)
Check for external fluid leaks from seals, gaskets, or cooler lines. Internal leaks (valve body) won't be visible but show as low pressure.
If external checks are inconclusive, transmission must be removed for internal inspection of clutch pack, brake band, valve body, and pump.
Symptoms: No forward movement in Drive, but Reverse works normally.
Cause: Worn clutch plates, broken return springs, or clutch piston seal failure. Usually occurs gradually with slipping before complete failure.
Solution: Transmission removal, clutch pack replacement, inspect valve body.
Symptoms: No reverse, but Drive functions normally.
Cause: Broken reverse brake band, failed servo piston, or adjust mechanism failure.
Solution: Replace brake band assembly and servo components.
Symptoms: No drive or reverse, engine revs freely, low hydraulic pressure.
Cause: Worn pump gears, damaged pump body, or broken pump drive mechanism.
Solution: Replace oil pump assembly, inspect pump drive components.
Symptoms: No drive or reverse, or intermittent engagement, normal engine sound.
Cause: Stuck valves from contamination, worn valve bores, or solenoid failures.
Solution: Valve body removal, cleaning, or replacement. Address fluid contamination source.
Record all symptoms, fault codes, and test results. Pattern recognition across multiple data points often reveals the root cause faster than guessing.
Many "transmission failures" are actually simple linkage or sensor issues. Always verify the basics before tearing into the transmission.
Hydraulic pressure data tells you immediately whether the issue is mechanical (clutch/brake) or hydraulic (pump/valve). Don't guess - test.
Burnt, black fluid with metal particles indicates catastrophic internal failure. Clean fluid with sudden failure suggests specific component breakage.
We provide complete diagnostic and repair services for no-drive and no-reverse issues.