Ambient/Battery Temperature Sensor Voltage Too High (Chrysler)
What does P1492 mean?
The P1492 code means the vehicle's onboard diagnostic system has detected: Ambient/Battery Temperature Sensor Voltage Too High (Chrysler). This is a low severity code.
Common Symptoms
- Check Engine Light illuminated
- Incorrect outside temperature display
- EVAP system monitors may not run
- Slightly altered cold-start fuel mixture
- No significant drivability issues
Probable Causes (Ranked by Likelihood)
- Faulty ambient temperature sensor Very High
- Open circuit in the sensor wiring High
- Corroded sensor connector Moderate
- Damaged wiring harness near the sensor Moderate
- PCM input circuit fault Low
Step-by-Step Diagnostic Procedure
-
Read the ambient temperature sensor value on a scan tool. Compare to actual outside temperature.
-
Locate the ambient temperature sensor (usually behind the front bumper) and inspect the connector.
-
Measure the sensor resistance with a multimeter. At 70F it should read approximately 10,000 ohms.
-
Check for open circuits in the wiring between the sensor and PCM.
-
Test the PCM input by applying a known resistance value at the connector.
Frequently Asked Questions
Where is the ambient temperature sensor located?
On most Chrysler and Dodge vehicles, the ambient temperature sensor is located behind the front bumper cover, usually near the center or ahead of the condenser. It is designed to measure outside air temperature.
Can this cause the EVAP monitor to not run?
Yes. The PCM uses ambient temperature to determine when conditions are right for EVAP testing. An inaccurate reading can prevent the monitor from running, causing an emissions test readiness failure.
Is this the same sensor as the one for the dash display?
On some vehicles, yes. On others, there is a separate sensor for the dashboard display and another for the PCM. Check your service manual to determine which sensor your vehicle uses.