P1885

DTC P1885: 3 - 1 Shift Malfunction

Solenoid Valve, Clutch and Brake Operation
Refer to Solenoid Valve, Clutch and Brake Operation.

Circuit Description
The special feature of 4HP 16 Automatic Transaxle is that it operates without freewheels. Shifting between individual gears takes place by means of overlapping clutch engagement and release. The advantage of overlap shifting are as follows:
- The transaxle can be of more compact design and is lighter on account of the absence of freewheels and the lower number of shift elements.
- Lower drag losses, i.e. higher efficiency.
- Lower peak torque acting on the components and driveline.

However, overlap shifting necessitates high-performance hardware and software, and precision engine signals.

Conditions for Setting the DTC
- Transaxle oil temperature is greater than -10 °C (14 °F).
- Selector lever is not in N (Neutral), P (Park) position.
- System voltage is greater than 9 V.
- No input speed error DTCs P0715, P0716 or P0717.
- Output speed is greater than 256 rpm.
- Input speed is greater than 400 rpm.
- 3 - 1 gear shift is active.

Action Taken When the DTC Sets
- The Malfunction Indicator Lamp (MIL) will illuminate.
- The TCM will record operating conditions at the time the diagnostic fails. This information will be stored in the Failure Records buffer.
- Adopt Emergency/Substitute mode and constant 3rd gear.
- Open lock-up clutch.

Conditions for Clearing the MIL/DTC
- The MIL will turn OFF when the malfunction has not occurred after three-ignition cycle.
- A history DTC will clear after 40 consecutive warm up cycles without a fault.
- Using a scan tool can clear history DTCs.

Diagnostic Aids
When DTC P1885 sets, the possible cause of fault could be TCM.

Troubleshooting