What does it mean?
P1895 is a Powertrain (engine, transmission, fuel system) fault code. It indicates: Engine Torque Delivered Circuit Malfunction (4L30-E) .
Symptoms
- Malfunction indicator lamp on, usually with codes in both modules
- Harsh, abrupt shifts because engine torque is not reduced during gear changes
- Shift quality changes noticeably with throttle position and load
- Flare followed by a hard engagement on upshifts
- Default (limp) operation in some conditions
- Drivability complaints mainly under acceleration rather than at steady cruise
Likely causes
- Open circuit or broken conductor on the torque signal wire between the modules
- Short to ground or to battery voltage on that wire
- Corroded, spread or backed-out terminals at either module connector
- Poor module ground causing an offset that makes the signal implausible
- ECM output driver for the torque signal failed
- Aftermarket wiring, an add-on tuning box or a previous repair splice interfering with the signal
- Failed input circuit in the TCM
How to fix it
- Read codes from both the engine and transmission modules and compare freeze frame data
- Check battery condition and the power and ground circuits of both modules
- Inspect and clean both module connectors, checking terminal tension
- Test the torque signal wire for continuity end to end and for shorts to ground and voltage
- Back-probe the circuit and observe the signal while accelerating, where the tool allows
- Look for and remove any non-standard splices or add-on devices on the circuit
- Repair the harness; confirm matching calibrations if a module has been replaced, and replace a module only as the last step