P0714-TRANSMISSION TEMPERATURE SENSOR INTERMITTENT
For a complete wiring diagram, refer to the Wiring Information.
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Theory of Operation
The Electrohydraulic Control Unit Assembly of the NAG1 transmission contains a temperature sensor to monitor the transmission oil temperature. This sensor is wired in series with the transmission Park/Neutral switch. The Transmission Control Module (TCM) expects to see a valid voltage level from the sensor when the shifter is in Reverse or any forward Drive position. The TCM also expects to see an open circuit condition when the shifter is in the Park or Neutral position. When the controller detects an open circuit when in Reverse or any forward drive position the DTC will set. Note: The TCM substitutes the Transmission Temperature reading with Engine Temperature due to an open circuit condition in Park or Neutral.
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When Monitored:
Continuously with the ignition on and the Transmission Temperature below 170 °C (338 °F).
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Set Condition:
When the TCM detects the Temperature sensor input changes more than 10 °C (18 °F) between each 20 mSec sensor read.
Possible Causes |
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| WIRING AND CONNECTORS |
| TRANSMISSION TEMPERATURE SENSOR - P/N SWITCH |
| TRANSMISSION CONTROL MODULE (TCM) |
Always perform the NAG1 Pre-Diagnostic Troubleshooting procedure before proceeding. (Refer to 28 - DTC-Based Diagnostics/MODULE, Transmission Control (TCM) - Standard Procedure).
1. CHECK WIRING AND CONNECTORS
| 1. | Ignition on, engine not running. |
| 2. | With the scan tool, monitor the Transmission Temperature. |
| 3. | Apply the parking brake. |
| 4. | With the brakes firmly applied, place the gear selector in Drive. |
| 5. | While monitoring the scan tool, wiggle the wires and connectors from the TCM to the Electrohydraulic Control Unit. |
Did the transmission temperature fluctuate while wiggling the wires?
Yes
- Repair the wiring and/or connectors as necessary.
- Perform the TRANSMISSION VERIFICATION TEST. (Refer to 28 - DTC-Based Diagnostics/MODULE, Transmission Control (TCM) - Standard Procedure).
No
- Go To 2
| 1. | Replace the Transmission Temperature Sensor in accordance with the Service Information. |
| 2. | Perform the TRANSMISSION VERIFICATION TEST. (Refer to 28 - DTC-Based Diagnostics/MODULE, Transmission Control (TCM) - Standard Procedure). |
| 3. | With the scan tool, read Transmission DTCs. |
Did DTC P0714 reset?
Yes
- Using the schematics as a guide, check the Transmission Control Module (TCM) terminals for corrosion, damage, or terminal push out. Pay particular attention to all power and ground circuits. If no problems are found, replace the TCM in accordance with the Service Information.
- Perform the TRANSMISSION VERIFICATION TEST. (Refer to 28 - DTC-Based Diagnostics/MODULE, Transmission Control (TCM) - Standard Procedure).
No