P1436

Ford

A/C Evaporator Air Temperature Circuit Low

Definition source: Manufacturer reference catalog
Definition verification: Not independently verified for display.
Time: Varies by diagnosis and vehicle | Diagnostic difficulty: Medium
Low Severity

The evaporator temperature sensor reports the temperature of air or the evaporator area to the climate-control system. This code indicates a low signal in that sensor circuit; it does not by itself prove the sensor is faulty. Depending on the vehicle’s control strategy, the air conditioner may cool inconsistently or limit compressor operation.

Report an error with this code

⚠️ Before You Begin (Safety First)

This fault usually does not make the vehicle unsafe to drive. Stop driving if poor defrosting or fogged windows prevent a clear view. Do not open refrigerant lines or attempt refrigerant service; the A/C system is pressurized and requires proper equipment.

Common Symptoms

  • There may be no noticeable symptoms, especially if the climate-control system continues to operate normally.
  • A/C cooling may be weak or inconsistent if the fault causes the system to limit compressor operation.
  • The compressor may cycle differently than expected, depending on how the vehicle’s climate-control system responds to the signal.
  • Evaporator icing or reduced airflow may occur in some circumstances if temperature feedback is inaccurate; this is not guaranteed by the code.

Common Causes

  • A faulty evaporator air-temperature sensor producing a low circuit signal.
  • A short to ground or damaged wiring in the sensor circuit.
  • A loose, corroded or damaged sensor connector.
  • A control-module or circuit issue, after the sensor and wiring have been checked.

Diagnostic Steps

  1. Confirm the stored code and check for related HVAC codes; other codes can help identify a broader circuit or control issue.
  2. With the vehicle safely parked and the system off, visually inspect accessible sensor wiring and connectors for damage, looseness or corrosion. Do not pull on wiring or force access to concealed components.
  3. If a scan tool can display HVAC temperature data, check whether the evaporator-temperature reading is plausible and whether it changes as expected. Interpret it using vehicle-specific service information.
  4. If the fault remains, have the sensor circuit tested against the correct wiring diagram and service procedure. Avoid guessing at terminals or replacing the sensor without confirming the circuit fault.
  5. Leave refrigerant-system work and inaccessible electrical testing to a qualified technician; do not open A/C lines.

When to Call a Professional

Use model-, year- and engine-specific service information. Check for related HVAC codes and, where available, compare the evaporator-temperature reading with other temperature data for plausibility. Inspect the sensor circuit and connectors, then test the sensor and wiring using the correct diagram and procedures. A low circuit signal can result from a sensor fault, wiring damage or a control-module issue; confirm the cause before replacing parts.

Compare component listings

Confirm diagnosis and vehicle fitment before buying. A listing does not prove that a part needs replacement. We may earn a commission from qualifying purchases.

Search Amazon Search eBay

Commonly Asked Questions

Does P1436 prove the evaporator temperature sensor needs replacement?

No. It identifies a low signal in the evaporator air-temperature circuit. The sensor, connector, wiring or control circuit could be responsible, so testing is needed before replacing a part.

Can I keep driving with this code?

Usually, yes. The main concern is reduced A/C or defrost performance. Do not drive if fogged windows or inadequate defrosting prevent a clear view.

Does this code mean the A/C refrigerant is low?

Not by itself. P1436 concerns the evaporator air-temperature circuit, not a direct measurement of refrigerant charge. Refrigerant diagnosis requires separate checks.

Why might the air conditioner behave differently with this code?

The climate-control system uses evaporator temperature information to manage A/C operation. An incorrect or low circuit signal may affect that control, but the exact response varies by vehicle.

Browse Available Code Guides

Previous and next available guides in database record order, across makes. Adjacent entries may share a code number and do not necessarily describe related faults.