P0538 1999 Ford F150 Code - A/C Evaporator Temperature Circuit High Input
Quick Answer
The A/C Evaporator Temperature (ACET) sensor contains a thermistor which receives a reference voltage from the Powertrain Control Module (PCM). Common causes include Faulty A/C Evaporator Temperature (ACET) Sensor, A/C Evaporator Temperature Sensor harness is open or shorted, A/C Evaporator Temperature Sensor circuit poor electrical connection. Severity is Low - monitor the vehicle and repair when practical. The vehicle can usually be driven if no severe symptoms are present, but symptoms should be checked before extended driving.
- What it means
- P0538 1999 Ford F150 indicates A/C Evaporator Temperature Circuit High Input .
- Common causes
- Common causes include Faulty A/C Evaporator Temperature (ACET) Sensor, A/C Evaporator Temperature Sensor harness is open or shorted, A/C Evaporator Temperature Sensor circuit poor electrical connection.
- Severity
- Low - monitor the vehicle and repair when practical.
- Can I drive?
- The vehicle can usually be driven if no severe symptoms are present, but symptoms should be checked before extended driving.
Code P0538 1999 Ford F150 Description
The PCM maintains evaporator core temperature and prevents icing of the evaporator core, by disengaging the A/C compressor clutch when the evaporator A/C Evaporator Temperature sensor reading falls below acceptable levels, and by engaging the A/C compressor clutch when the discharge air temperature rises above acceptable levels.
The A/C Evaporator Temperature sensor is located inside of the heater core and evaporator core housing in the air-stream leaving the evaporator core.
The Diagnostic Trouble Code (DTC) indicates the A/C Evaporator Temperature sensor signal input is greater than Self-Test minimum. Self-Test maximum is 4.5 volts.
What are the Possible Causes of the DTC P0538 1999 Ford F150?
- Faulty A/C Evaporator Temperature (ACET) Sensor
- A/C Evaporator Temperature Sensor harness is open or shorted
- A/C Evaporator Temperature Sensor circuit poor electrical connection
- Faulty Powertrain Control Module (PCM)
How to Fix the DTC P0538 1999 Ford F150?
Review the 'Possible Causes' above and visually examine the corresponding wiring harness and connectors. Check for damaged components and inspect connector pins for signs of being broken, bent, pushed out, or corroded.
What is the Cost to Diagnose the Code?
Labor: 1.0
To diagnose the P0538 1999 Ford F150 code, it typically requires 1.0 hour of labor. Rates vary by location, vehicle, and shop. Many shops charge between $80–$150 per hour; dealerships and metro areas may be higher, independents may be lower.
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Frequently Asked Questions about P0538 1999 Ford F150 Code
1. What are the common symptoms of OBDII code P0538 in a 1999 Ford F150?
- The common symptoms include a malfunctioning air conditioning system, lack of cold air from the vents, and possible issues with climate control.
2. What does the OBDII code P0538 "A/C Evaporator Temperature Circuit High Input" indicate in a 1999 Ford F150?
- This code suggests that the A/C evaporator temperature sensor is detecting a high input signal, which may lead to improper cooling performance.
3. What are the possible causes of OBDII code P0538 in a 1999 Ford F150?
- The code can be triggered by a faulty A/C evaporator temperature sensor, wiring issues, sensor connector problems, or a malfunction in the climate control system.
4. How can I diagnose the root cause of OBDII code P0538 in my 1999 Ford F150?
- Diagnosing the issue involves checking the A/C evaporator temperature sensor, inspecting the sensor wiring and connector for damage, and testing the climate control system for any faults.
5. Can I continue driving my 1999 Ford F150 with OBDII code P0538 without repairing it?
- It is not recommended to ignore this code, as it can lead to poor A/C performance and discomfort while driving. Getting it repaired promptly is advisable.
6. Is it possible to reset OBDII code P0538 in a 1999 Ford F150 without fixing the underlying issue?
- While you can clear the code using an OBDII scanner, it will likely reappear if the root cause is not addressed. Resetting without fixing the problem is only a temporary solution.
7. How much does it typically cost to repair OBDII code P0538 in a 1999 Ford F150?
- The cost of repair can vary depending on the exact cause of the issue. It can range from replacing a sensor or repairing wiring to addressing more complex climate control system issues.
8. Are there any DIY tips for fixing OBDII code P0538 in a 1999 Ford F150?
- DIY enthusiasts can start by checking the sensor and its wiring for visible damage. However, for accurate diagnosis and repair, it is recommended to consult a professional mechanic.
9. Can extreme weather conditions affect the triggering of OBDII code P0538 in a 1999 Ford F150?
- Yes, extreme heat or cold can potentially impact the A/C system and trigger this code. It is essential to maintain the A/C system regularly to prevent such issues.
10. Will OBDII code P0538 cause any long-term damage to my 1999 Ford F150 if left unresolved?
- Ignoring this code can lead to continued poor A/C performance, discomfort while driving, and potential strain on other components in the climate control system. Resolving it promptly is advisable.
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