Range Rover Velar B1366-92 With No A/C? Clear Once, Then Let the Return Decide

B1366-92? Clear Once, Then Rescan

Save B1366-92 and the vent-temperature complaint before clearing anything. JLR’s current service message calls for one deliberate test: confirm the code in the HVAC module, clear it, cycle the ignition and rescan. If B1366-92 returns, the workshop replaces HVAC assembly 18N407, retains it and raises an EPQR referencing project P368338 and SSM76485. If it does not return, the message does not authorize assembly replacement; continue normal TOPIx diagnosis for the actual A/C symptom.

If B1366-92 does not return and TOPIx sends the case into normal refrigerant diagnosis, digital manifold gauges can help relate pressure and line temperature on a compatible system. An MRCARTOOL L505 can support that later branch. L505 can support refrigerant pressure and temperature measurements on a compatible system after the code-return branch and JLR refrigerant procedure call for them; it cannot communicate with the HVAC module, reproduce an evaporator-sensor performance fault from pressure alone, authorize 18N407 replacement, evacuate or recover refrigerant or submit the EPQR.

One code clear is useful here because JLR gives it a question to answer. Clearing the same code every visit is not diagnosis; confirming it, clearing once, cycling the ignition and seeing whether it returns is the defined gate between continued testing and HVAC assembly replacement.

Save the code and exact cooling complaint

Before touching the fault memory, record B1366-92 in the HVAC module with status, mileage and any companion codes. Measure left and right vent temperature, note selected temperature, blower speed, outside temperature and how long the system had been running. Ask whether airflow is missing or merely warm. Photograph control settings and save the complete scan. JLR describes A/C not operating as expected, but a weak blower, a warm outlet and an intermittent damper fault are different experiences. The original data lets the post-cycle result be compared with the actual customer complaint.

Confirm the 2023-onward Velar scope

SSM76485 covers Range Rover Velar L560 vehicles from 2023 model year onward, all derivatives, at the communication’s stated revision. Confirm the model and current TOPIx information rather than applying the process to an F-PACE or another Range Rover with the same code. Check repair history for dash, HVAC, evaporator-sensor or battery work. The message says engineering is investigating the cause, so do not expand it into a universal explanation for every B1366-92. If a newer procedure supersedes it, that current information controls.

Do not confuse airflow with air temperature

Hold a tissue near the vent to compare airflow, and use a thermometer to compare temperature. Strong airflow that never cools may involve compressor, refrigerant or temperature-mixing control; little airflow can point toward blower, filter, door or evaporator icing. B1366-92 is described as right-front temperature-damper performance or incorrect operation while the text mentions evaporator-sensor behavior. Preserve that exact wording instead of translating it into ‘low gas.’ Do not connect gauges or add refrigerant simply because the cabin is warm.

Clear B1366-92 only once for the test

With the original scan saved, confirm B1366-92, clear it once and complete the prescribed ignition cycle. Avoid clearing all modules repeatedly, disconnecting the battery or operating a series of unrelated actuator tests between those steps. The purpose is to ask whether this exact fault returns under the controlled reset. Record the time and vehicle state. If another safety or power-supply code demands priority, address it through TOPIx rather than corrupting the one-clear test. A deliberate clear can create evidence; casual clearing destroys it.

Result of the one-clear test	Direction
B1366-92 returns after ignition cycle	Replace 18N407, retain it and file the EPQR
B1366-92 does not return but A/C is still poor	Continue normal TOPIx A/C diagnosis
Airflow low rather than merely warm	Prioritize blower, filter, door or icing evidence
Other power or communication codes present	Address the controlling fault before forcing this branch

Cycle the ignition and rescan immediately

Rescan the HVAC module immediately after the ignition cycle and save the result. If B1366-92 returns, the SSM opens the assembly-replacement branch. If it does not return, the communication does not authorize replacement; reproduce the A/C complaint and follow normal diagnosis. Do not continue cycling until the code happens to come back. Intermittent behavior should be documented with operating state and customer conditions, not manufactured by endless resets. One clear, one cycle and one saved rescan make the decision auditable.

Replace 18N407 only if the code returns

When the code returns through the defined gate, JLR directs replacement of HVAC assembly 18N407. Follow current TOPIx for refrigerant recovery, interior disassembly, electrical isolation, seals, oil balance and programming or calibration. This is extensive work, so protect trim and record every connector. Do not replace only a temperature actuator or evaporator sensor because its name appears in the fault description unless JLR revises the instruction. The returning-code branch—not pressure alone—authorizes the assembly decision in this service message.

Retain the assembly and raise the EPQR

Retain the removed HVAC assembly and raise an EPQR that references project P368338 and SSM76485, confirming the part is held. Attach original and post-cycle scans, symptom measurements and repair details. Engineering retention is part of the diagnostic feedback loop, not administrative clutter. Do not discard or dismantle the assembly before instructions arrive. If the code did not return and another cause is found, document that separate evidence rather than filing an EPQR that implies the JLR branch was met.

Continue normal A/C diagnosis when the gate is not met

If the return-code gate is not met, follow normal A/C diagnosis: confirm airflow, sensor data, compressor request, pressure, line temperatures, refrigerant mass and leak evidence through the exact vehicle procedure. Recover and weigh refrigerant instead of topping off by pressure. After any repair, compare vent performance at the same ambient and settings and rescan. If 18N407 was replaced, complete calibration and prove both temperature zones. Give the owner the before/after temperatures, code-return result and final repair so ‘no A/C’ ends with a reproducible answer.

The value of this JLR instruction is its discipline. Save B1366-92 and the real cabin complaint, clear once, cycle once and rescan. Stop before refrigerant recovery or dash-level disassembly unless a qualified workshop is following the current TOPIx procedure. A returning code sends the workshop to 18N407 replacement, retained-part handling and an EPQR; a non-return sends it back to normal HVAC evidence, where pressures are only one part. Verify the outcome with the final scan and matched vent-temperature test, then keep those records with the invoice so a later intermittent visit starts from evidence instead of another reset. That keeps an expensive repair tied to a repeatable gate and gives the owner a result they can understand.

Official references

• JLR SSM76485—Velar A/C Inoperative and B1366-92
• NHTSA Recall Lookup