DTC P0712: TRANS TEMP SENSOR VOLTAGE TOO LOW
Circuit Description
Circuit is monitored continuously while ignition is on and engine is running. DTC sets if transmission temperature sensor voltage is less than 1.55 volts for 2.2 seconds.
Possible Cause
- Transmission temperature sensor wiring harness defective.
- Governor pressure/temperature sensor defective.
- Transmission temperature signal circuit shorted to ground.
- Transmission temperature signal circuit shorted to sensor ground circuit.
- PCM defective.
Diagnostic Procedure
1. Turn ignition on. Using scan tool, read DTCs. If good trip counter for DTC P0712 is displayed and is equal to zero, go to next step. If good trip counter is not displayed, or is not equal to zero, go to step 11 .
2. Turn ignition off. Disconnect transmission solenoid harness connector. Disconnect PCM harness connectors. Inspect connectors and terminals for damage. Repair as necessary. Measure resistance between ground and 5-volt supply circuit at transmission solenoid harness connector terminal No. 2. If resistance is 100 k/ohms or less, repair circuit for short to ground. If resistance is more than 100 k/ohms, go to next step.
3. Measure resistance between sensor ground circuit and 5-volt supply circuit at transmission solenoid harness connector terminals No. 2 and 3. If resistance is 100 k/ohms or less, repair 5-volt supply circuit for short to sensor ground circuit. If resistance is more than 100 k/ohms, go to next step.
4. Measure resistance between ground and temperature sensor signal circuit at transmission solenoid harness connector terminal No. 8. If resistance is 100 k/ohms or less, repair circuit for short to ground. If resistance is more than 100 k/ohms, go to next step.
5. Measure resistance between sensor ground circuit and sensor signal circuit at transmission solenoid harness connector terminals No. 3 and 8. If resistance is 100 k/ohms or less, repair sensor signal circuit for short to sensor ground circuit. If resistance is more than 100 k/ohms, go to next step.
6. Ensure transmission solenoid harness connector is disconnected. Remove transmission oil pan. Disconnect governor pressure/temperature sensor harness connector. Inspect connector and terminals for damage. Repair as necessary. Measure resistance between ground and 5-volt supply circuit at governor pressure/temperature sensor harness connector terminal "A". See Fig. 38 . If resistance is 100 k/ohms or less, replace transmission solenoid assembly (internal transmission harness). See REMOVAL & INSTALLATION in appropriate SERVICING article in AUTOMATIC TRANSMISSIONS. If resistance is more than 100 k/ohms, go to next step.
7. Measure resistance between sensor ground circuit and 5-volt supply circuit at governor pressure/temperature sensor harness connector terminals "A" and "D". If resistance is 100 k/ohms or less, replace transmission solenoid assembly (internal transmission harness). See REMOVAL & INSTALLATION in appropriate SERVICING article in AUTOMATIC TRANSMISSIONS. If resistance is more than 100 k/ohms, go to next step.
8. Measure resistance between terminals "C" and "D" at governor pressure/temperature sensor (component side) connector. See TRANSMISSION TEMPERATURE SENSOR RESISTANCE table. If resistance is within specifications, go to next step. If resistance is not within specification, replace governor pressure/temperature sensor. See REMOVAL & INSTALLATION in appropriate SERVICING article in AUTOMATIC TRANSMISSIONS.
9. Measure resistance between ground and temperature sensor signal circuit at governor pressure/temperature sensor harness connector terminal "C". If resistance is 100 k/ohms or less, replace transmission solenoid assembly (internal transmission harness). See REMOVAL & INSTALLATION in appropriate SERVICING article in AUTOMATIC TRANSMISSIONS. If resistance is more than 100 k/ohms, go to next step.
10. Measure resistance between temperature sensor signal circuit and sensor ground circuit at governor pressure/temperature sensor harness connector terminals "C" and "D". If resistance is 100 k/ohms or less, replace transmission solenoid assembly (internal transmission harness). See REMOVAL & INSTALLATION in appropriate SERVICING article in AUTOMATIC TRANSMISSIONS. If resistance is more than 100 k/ohms, replace PCM. See appropriate REMOVAL, OVERHAUL & INSTALLATION article in ENGINE PERFORMANCE.
11. Conditions required to set DTC are not currently present. Inspect all applicable connectors and terminals for damage. Repair as necessary. If connectors and terminals are okay, see INACTIVE DTC CONDITION under SELF-DIAGNOSTIC SYSTEM. Testing is complete.