The special feature of a 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 advantages of overlap shifting are as follows:
• | The transaxle can be a 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.
• | The engine is running. |
• | DTC P0781, P0782, P1881, P1883, P1884, P1885, P1886 are not set. |
• | The selector lever is not in the neutral (N) or park (P) position. |
• | Engine torque is unstable state. |
• | The malfunction indicator lamp (MIL) will illuminate. |
• | The transmission control module (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 |
• | The MIL lamp will turn OFF when the malfunction has not occurred after 3 ignition cycles. |
• | A history DTC will clear after 40 consecutive warm-up cycles without a fault. |
• | Using a scan tool can clear history DTCs. |
When DTC P0783 sets, the replacement of T/M is recommended.
Step | Action | Value(s) | Yes | No |
---|---|---|---|---|
1 | Did you perform the Diagnostic System Check - Automatic Transmission? | -- | Go to Step 2 | |
2 |
Was the condition found and corrected? | -- | Go to Diagnostic System Check - Engine Controls in Engine Controls-2.0L | Go to Step 3 |
3 | Inspect the electronic control module (ECM). Was a condition found? | -- | Go to Engine Control Module Replacement in Engine Controls-2.0L | Go to Step 4 |
4 |
Is the voltage within the specified values? | 11-14 V | Go to Step 5 | |
5 | Replace the TCM. Did you complete the replacement? | -- | Go to Step 6 | -- |
6 |
Has the last test failed or is the current DTC displayed? | -- | Go to Step 7 | System OK |
7 | Replace the transaxle assembly. Refer to Transmission Replacement Did you complete the replacement? | -- | Go to Step 8 | -- |
8 |
Has the last test failed or is the current DTC displayed? | -- | Go to Step 2 | System OK |