AutoCodesPontiac – P1684 Pontiac

P1684 Pontiac Code - Transmission Control Module Power Up Temperature Sensor Performance

Quick Answer

The Transmission Control Module (TCM) power up the temperature sensor is located inside of the control solenoid (w/body and TCM) valve assembly and has no serviceable parts. Common causes include Reprogram TCM and recheck code, Replace Transmission Control Module (TCM) Sensor/body assembly one piece. Severity is High - diagnose this code as soon as possible. Driving is not recommended if the warning light is flashing, the engine runs poorly, or safety-related symptoms are present.

What it means
P1684 Pontiac indicates Transmission Control Module Power Up Temperature Sensor Performance.
Common causes
Common causes include Reprogram TCM and recheck code, Replace Transmission Control Module (TCM) Sensor/body assembly one piece.
Severity
High - diagnose this code as soon as possible.
Can I drive?
Driving is not recommended if the warning light is flashing, the engine runs poorly, or safety-related symptoms are present.
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Code Popularity 2,983
How popular is this code, among other codes? Low
Table of contents Created and updated by William Orellana on Sep 09, 2019
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Code P1684 Pontiac Description

The Transmission Control Module (TCM) power up the temperature sensor is located inside of the control solenoid (w/body and TCM) valve assembly and has no serviceable parts. The TCM power up temperature sensor provides the temperature pof the TCM at TCM power up. This temperature readings is used in various shifting and diagnostic routines in the TCM software. This fault is handled inside the TCM and no external circuit are involved.
OBDII Code P1684 Pontiac - Transmission Control Module Power Up Temperature Sensor Performance - AutoCodes.com
P1684 Pontiac Code - Transmission Control Module Power Up Temperature Sensor Performance

What are the Possible Causes of the DTC P1684 Pontiac?

  • Reprogram TCM and recheck code
  • Replace Transmission Control Module (TCM) Sensor/body assembly one piece

How to Fix the DTC P1684 Pontiac?

Review the 'Possible Causes' above and visually examine the corresponding wiring harness and connectors. Check for damaged components and inspect connector pins for signs of being broken, bent, pushed out, or corroded.

What is the Cost to Diagnose the Code?

Labor: 1.0

To diagnose the P1684 Pontiac code, it typically requires 1.0 hour of labor. Rates vary by location, vehicle, and shop. Many shops charge between $80–$150 per hour; dealerships and metro areas may be higher, independents may be lower.

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Need Help with the Code?

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About the author: William Orellana is a Master Mechanic and Mechanical Engineer with over 30 years of experience diagnosing and repairing vehicles. Learn more about his background.

Frequently Asked Questions about P1684 Pontiac Code

1. What does the OBDII code P1684 mean for a Pontiac?

P1684 indicates an issue with the Transmission Control Module (TCM) detecting a problem with the power-up temperature sensor’s performance.

2. What are the common symptoms of code P1684 in a Pontiac?

Symptoms may include transmission shifting issues, the check engine light turning on, reduced fuel efficiency, and erratic or delayed gear changes.

3. What causes the P1684 code to appear in a Pontiac?

Common causes include a faulty power-up temperature sensor, wiring issues, poor electrical connections, or a malfunctioning Transmission Control Module.

4. Can I drive my Pontiac with the P1684 code active?

While the vehicle may still be drivable, it’s not recommended to ignore the issue as it can lead to further transmission damage or reduced performance.

5. How is the P1684 code diagnosed in a Pontiac?

A mechanic will use an OBDII scanner to verify the code, inspect the TCM and temperature sensor, check for wiring or connection issues, and possibly test the transmission fluid temperature sensor.

6. How do you fix the P1684 code on a Pontiac?

Repairs may include replacing the power-up temperature sensor, repairing damaged wiring, cleaning or reconnecting electrical connections, or replacing the TCM if necessary.

7. Can low transmission fluid cause the P1684 code?

Low or degraded transmission fluid is unlikely to directly cause P1684 but can contribute to overheating or other transmission problems that may trigger related codes.

8. How much does it cost to repair the P1684 code on a Pontiac?

Repair costs vary but may range from $100 to $500 depending on whether the issue involves sensor replacement, wiring repairs, or TCM replacement.

9. Is the P1684 code specific to Pontiac vehicles?

No, while P1684 is common in certain Pontiac models, it can appear in other vehicles with similar TCM systems, but the exact definition may vary.

10. How can I prevent the P1684 code from reoccurring in my Pontiac?

Regular maintenance, checking transmission fluid levels, ensuring proper electrical connections, and addressing any TCM issues promptly can help prevent this code.

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