Error Code P1676 is defined as FPTDR (Frame-To-Powertrain Torque Down Request) Signal Line Failure.
This error code is a manufacturer-specific trouble code, meaning it does not apply to all vehicles makes. Rather, it applies only to specific vehicle makes, such as Acura, GM, Honda, Saab, Volkswagen/Audi, and Volvo. Specification on the definition, troubleshooting, and repairs still vary from one make and model to another.
Error Code P1676 happens when the PCM (powertrain control module, also known as ECM or engine control module in other vehicle makes) has detected a malfunction in the data line between the TCM (Traction Control Module) and the PCM.
As with other error codes, this code activates the Check Engine light and registers the error code to the vehicle.
There are a couple of factors that contribute to this error code, such as:
- Open or shorts in the data line
- Problem between the PCM and the ABS/TCS unit
- Failed PCM
How to Check and Fix
The first thing you can do is to reset the PCM. Then, start the engine and wait for about 10 seconds.
If the Error Code is indicated, proceed to the next step.
If the problem doesn’t come back, then the intermittent failure system is fine at this time. You can check the wires at the ABS/TCS control unit and look for signs of poor connections or loose wires. Also, include the wires and connections leading to the PCM.
If the code comes back turn Off the ignition, disconnect the PCM connector E (12P) and the ABS/TCS control unit 16P connector. Check for the continuity between body ground and PCM connector terminal E1.
If there is continuity, repair the short in the wire between the ABS/TCS control unit and the PCM (E1).
If there is none, check the continuity between the ABS/TCS control unit 16P connector terminal No. 1 and PCM connector terminal E1.
Reconnect the PCM connector E (12P)
Connect PCM connector terminals E1 and C28 with a jumper wire. Reset the PCM and then start the engine and wait for around 60 seconds.
If the vehicle indicates another code in the form of Error Code 1678, simply substitute a known-good ABS/TCS control unit and recheck. If the symptom/indication goes away, replace the original ABS/TCS control unit.
If it does not show another error code, replace the PCM and recheck. If the symptom/indication goes away, you need to replace the original PCM.
As with other error codes, it is always recommended to have this problem fixed by a certified specialist, especially if you’re not confident with your knowledge and skills on auto repair.