What does it mean?
P1698 is a Powertrain (engine, transmission, fuel system) fault code. It indicates: Engine Torque Control Cut Signal Circuit Malfunction (Low Input) .
Symptoms
- MIL on with harsh, jolting gear changes
- Transmission dropping into limp mode with a single fixed gear
- Noticeable driveline shock during upshifts under load
- Engine power feeling reduced or inconsistent
- Related communication codes stored in the transmission module
- Shift flare followed by a hard engagement
Likely causes
- Torque cut signal wire shorted to ground between the two modules
- Open circuit on the signal line so the input sits at its low limit
- Corroded or damaged terminals at either module connector
- Failed output driver in the module that sends the torque cut request
- Poor ground reference shared by both modules, shifting the measured level
- Harness damage left behind by earlier repair work or an accessory installation
- Faulty input circuit in the receiving module
How to fix it
- Scan both modules and note which one reports the fault and which one is missing the signal
- Look up the torque cut circuit in the wiring diagram and check it end to end for continuity
- Measure the circuit for a short to ground with both modules disconnected
- Inspect the connectors and the harness section between the two modules for chafing and corrosion
- Voltage drop test the grounds of both modules under load
- Repair the damaged wiring with a sealed joint and confirm with a road test under load
- Replace the sending module only if the wiring is intact and the output stays low when it is commanded high