99 Acura 3.2TL P1676 Code: FPTDR Signal Line Failure and Engine Stalling Solutions
My 1999 Acura 3.2TL is consistently showing fault code P1676, which stands for 'FPTDR Signal Line Failure'. The car occasionally stalls while driving and then fails to start — it turns over briefly and starts for a second before dying suddenly. This behavior suggests either insufficient fuel delivery or a sensor disconnecting during operation. I'm looking for accurate explanations of what P1676 means and practical steps I can take to diagnose and fix the issue. Any insights from experienced Acura owners or mechanics would be greatly appreciated.
Yes, this vehicle has an automatic transmission. Code P1676 indicates a fault in one of the data lines connecting the Transmission Control Module (TCM) to the Powertrain Control Module (PCM). The issue could stem from a short or open circuit in the wiring harness. Start by visually inspecting the transmission area for any frayed wires, damaged insulation, or loose connections — especially around the TCM and PCM wiring harnesses. If the wiring appears intact, consider that one of the sensors might be causing a short to ground or an incorrect reference voltage. On Honda/Acura systems, the reference voltage is typically 5V. When the engine stalls, check for this reference voltage at key engine sensors such as the MAF (Mass Airflow) or MAP (Manifold Absolute Pressure), using a multimeter and referencing your Haynes manual for wire colors and sensor locations. If you measure no voltage or 12 volts instead of 5V, it likely points to a short or open circuit in the VREF line — most commonly due to a faulty or shorting sensor. While a failing TCM or PCM is possible, it's less common and would require more extensive diagnostics.