P0514

P0514-BATTERY TEMPERATURE SENSOR PERFORMANCE





For complete wiring diagrams refer to Diagrams/Electrical.


Theory of Operation

There are two parts to this fault code, a key on check and a rationality check. After an 8 hour cold soak, at key ON the readings for the ambient air temperature, battery temperature and intake air temperature and coolant temperature are all compared. If the temperatures differ more than a calibrated amount, then the appropriate sensor fault code would be recorded. The key on monitor is disabled for ambient temperatures below -6.7°C (20° F). This monitor looks for all the sensors to be grouped on one temperature or, in the case that the monitor fails, three sensors grouped at one temperature and one outlier. In the case that all four sensor values are distributed over a range of temperatures this diagnostic will not run. A block heater is one possible cause of such a distribution. The rationality check is referred to as a dither. The dither looks at the temperature reading from the sensor over time and ensures that it changes. This monitor is used to detect a "stuck" sensor. If the sensor reading does not change over a calibrated time limit, the fault will be recorded. Both the key-on and dither portions of this rationality error require that the diagnostic fails in two consecutive drive cycles before the MIL lamp is lit. During this time the ECM uses an default value for the intake air temperature. The ECM turns off the MIL lamp when the diagnostic runs and passes in 4 consecutive drive cycles.

- When Monitored:

Key on engine off and while engine is running.

- Set Condition:

At key on engine off, the intake air temperature sensor reads differently than the battery temperature and ambient air temperature sensors. Or while the engine is running the ECM does not read a change in value from the intake air temperature sensor over time.







Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding.

Diagnostic Test


1. BATTERY TEMP SENSOR

Remove the temperature sensor and reconnect the wiring harness connector to the sensor.

Monitor scan tool, while heating the sensor with an external heat source (DO NOT USE OPEN FLAME).

Does the reading from the sensor increase at least -15° C (5° F). on the scan tool?

Yes

- Refer to the INTERMITTENT CONDITION Diagnostic Procedure. Intermittent Condition

No

- Replace the battery temperature sensor.
- Perform POWERTRAIN VERIFICATION TEST. Powertrain Verification Test