Fix P0710 Mechanic’s solutions that WORKED

The P0710: Transmission Fluid Temperature Sensor Circuit Malfunction signifies a malfunction in the transmission fluid temperature sensor circuit. This sensor is crucial for monitoring the transmission’s operating temperature, which is vital for its proper functioning. If the sensor or its circuit has issues, it can lead to incorrect temperature readings, affecting the transmission’s performance and longevity.

P0710 quick overview

Meaning	P0710: Transmission Fluid Temperature Sensor Circuit Malfunction
Is it serious?	Yes, this code can be serious as it may lead to transmission issues and potentially expensive repairs if not addressed promptly.
Possible causes	– Faulty transmission fluid temperature sensor – Wiring issues or damaged connectors in the sensor circuit – Transmission fluid contamination or level issues – Problems with the vehicle’s transmission control module (TCM)
How to diagnose?	Inspect Sensor and Wiring: Check the transmission fluid temperature sensor and its wiring for damage or corrosion. Test Sensor Circuit: Perform electrical testing on the sensor circuit for continuity and shorts. Monitor Transmission Temperature: Use diagnostic tools to monitor the actual transmission temperature. Check Transmission Fluid: Ensure the transmission fluid is clean and at the correct level. Evaluate TCM: Investigate the Transmission Control Module for faults or software updates.

How to fix P0710 – learn from mechanics

I looked into P0710 service cases at iatn.com website where in the private forums the mechanics seek advice from other mechanics. I looked up a bunch of cases to help you decide how to fix your issue and see what would a real mechanic do to solve it.

Case #1: Jeep

Vehicle Information: 2005 Jeep Grand Cherokee Limited 5.7L

Issue + Repair History:

• Check engine light on and transmission sometimes won’t upshift.
• Turning off and restarting the Jeep temporarily resolves the issue.
• Pulled codes: P0700, P0710, U0404, P0607.
• Cleared codes, and vehicle shifted fine after driving.
• Checked connections and shift linkage, which looked good.

Other OBD2 Codes + Test Results:

• Codes – P0700, P0710, U0404, P0607

Suggestions to Fix Issue:

• Replace the Electronic Shift Module (ESM) as per TSB 21-016-06.
• Look into the shifter module, which might be causing the issue.
• Research possible cost-effective options for replacing the ESM or shifter bezel.

Final Fix:

• Replaced the ESM with a used shift assembly from a local wreck yard at a fraction of the cost of a new module.
• No more lights, shifts great, and customer is happy.

Case #2: Nissan

Vehicle Information: 2008 Nissan Altima S 2.5L

Issue + Repair History:

• Customer experienced a “buzzing” noise and the check engine light came on during a trip.
• Stored code P0710 in the PCM indicating transmission temperature sensor high or low.
• Fluid temperatures started low but reached as high as 271 degrees during a test drive.
• Transmission did not cool down during driving.
• Vehicle has 149,000 miles on it.

Computer Codes & Descriptions:

• P0710 – Transmission Temperature Sensor High or Low

Suggestions to Fix Issue:

• Check for a blocked oil cooler line, as temperatures above 175-180°F can damage the transmission.
• Consider that the transmission might need replacement due to possible internal wear and high temperatures.
• Flush the entire transmission system if replacing.
• Contact Nissan for an estimate on an OE remanufactured transmission unit.

Final Fix:

• The high temperature was due to internal wear in the transmission.
• Nissan dealer confirmed the need for a new transmission but it was not under warranty.
• Scheduled to install a Nissan transmission unit at approximately $2,200 plus 5 quarts of CVT fluid at $20 per quart.

Case #3: Ford

Vehicle Information: 2005 Ford E-350 Super Duty 6.0L

Issue + Repair History:

• Check engine light and overdrive switch flashing on cold starts.
• Temperature reading -40, then reads correctly after warming up.
• Temp sensor checked and within specs.
• Replaced transmission temperature sensor with a dealer part.
• Van is used frequently for highway driving as part of a fleet.

Other OBD2 Codes + Test Results:

• P0710 – Trans Temp Sensor Fault
• P0713 – Temp Sensor High Input

Suggestions to Fix Issue:

• Check for wiring problems, especially circuits going open.
• Examine connector faces for pushed out pins or intermittent contact.
• Check signal at ECM for possible broken wire.
• Inspect wiring harness at common problem areas: over the back of the transmission, underside of the doghouse, and where the harness crosses at the left front of the engine.

Final Fix:

• Identified the problem as wiring related.
• Replaced the internal wiring harness assembly with an updated part from Ford.
• After replacement, resistance measured only .2 ohms above the temp sensor, solving the problem.

Case #4: Lexus

Vehicle Information: 2003 Lexus RX300 3.0L

Issue + Repair History:

• ATF temperature light came on during a long drive, followed by the MIL.
• Stored code P0710 for transmission fluid temperature sensor malfunction.
• Initial difficulty in finding a replacement switch or part number.
• Transmission wire harness part #82125A did not clearly show the temp sensor.

Related Repair History:

• Sought to replace the transmission fluid temp sensor.

Computer Codes & Descriptions:

• P0710 – Trans Fluid Temp Switch Malfunction

Suggestions to Fix Issue:

• Temp sensor is part of the transmission wire harness.
• Recommended to test at the plug for any wiring issues.
• Check if the long drive caused overfilling or foaming of the transaxle fluid, potentially affecting the sensor.

Final Fix:

• Confirmed that the ATF temp sensor is part of a short harness, part number 82125-06010.
• Replaced the internal wire harness, accessed through the trans pan.
• Refilled with Toyota T4 transmission fluid, resolving the issue.

Case #5: Chrysler

Vehicle Information: 2005 Chrysler 300 Limited 3.5L

Issue + Repair History:

• Check engine light on, transmission in limp mode (1st gear).
• Codes displayed: P0717 (input speed sensor 1 circuit no signal), P0657 (solenoid supply voltage circuit), P0710 (transmission temperature sensor circuit).
• Replaced input speed sensor with OEM part, but issues persisted after test drive.

Related Repair History:

• First time encountering this transmission issue.
• Previous unrelated repair over a year ago for cooling fan assembly.

Other OBD2 Codes + Test Results:

• P0717 – Input Speed Sensor 1 Circuit No Signal
• P0657 – Solenoid Supply Voltage Circuit
• P0710 – Transmission Temperature Sensor Circuit

Suggestions to Fix Issue:

• Check all fuses, including any that might be missing.
• Read input shaft speed sensor output on scanner to diagnose.
• Inspect wiring for damage or loose connections.
• Consider possibility of wiring harness melting or damage.
• Check transmission connector for ATF leakage.
• Investigate potential TCM (Transmission Control Module) issues.

Final Fix:

• Discovered chewed MAP & CAM sensor wires indicating rodent damage.
• Found chewed wires in the transmission harness near the firewall.
• Repaired the damaged wires, resolving the issue.

Advice	Brief Description of Diagnostic Step
Check Wiring and Connectors	Inspect the wiring harness and connectors for damage, corrosion, or loose connections.
Examine Transmission Fluid Temperature Sensor	Investigate the condition and functionality of the transmission fluid temperature sensor.
Test Sensor Circuit	Perform electrical tests on the sensor circuit, including checking for continuity and shorts.
Look for Potential Wiring Harness Issues	Search for any signs of wear, rubbing, or damage on the wiring harness, especially near hot components or moving parts.
Consider Transmission Control Module (TCM)	Check the TCM for faults or the need for updates, as it can impact sensor readings.
Monitor Transmission Temperature	Use diagnostic tools to monitor transmission temperature and verify sensor readings.
Check for External Factors Affecting the Sensor	Look for issues like fluid contamination, overheating, or mechanical damage affecting sensor performance.
Replace Sensor if Necessary	If diagnostics indicate, replace the transmission fluid temperature sensor with an OEM or compatible part.