The special feature of the 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 of 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 transmission oil temperature is greater than -10°C (+14°F). |
• | The selector lever is not in the neutral (N) or park (P) position. |
• | The system voltage is greater than 9 volts. |
• | No input speed error DTCs P0715, P0716, or P0717 are set. |
• | The output speed is greater than 256 RPM. |
• | The input speed is greater than 400 RPM. |
• | The 4-3 gear shift is active. |
• | 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 4th 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 P1884 sets, the possible cause of the fault could be the TCM.
Step | Action | Value(s) | Yes | No |
---|---|---|---|---|
1 | Did you perform the Diagnostic System Check - Automatic Transmission? | -- | Go to Step 2 | |
2 |
Was a condition found? | -- | 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 or Engine Control Module Replacement in Engine Controls-2.5L | Go to Step 4 |
4 |
Is the voltage within the specified values? | 11-14 V | Go to Step 5 | |
5 | Replace the TCM. Refer to Transmission Control Module Replacement . 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 | Repair and/or replace the transaxle, as necessary. Did you complete the repair? | -- | Go to Step 8 | -- |
8 |
Are there any DTCs displayed that have not been diagnosed? | -- | Go to Step 2 | System OK |
The special feature of the 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 of 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 transmission oil temperature is greater than -10°C (+14°F). |
• | The selector lever is not in the neutral (N) or park (P) position. |
• | The system voltage is greater than 9 volts. |
• | No input speed error DTCs P0715, P0716, or P0717 are set. |
• | The output speed is greater than 256 RPM. |
• | The input speed is greater than 400 RPM. |
• | The 4-3 gear shift is active. |
• | The hold lamp will blink. |
• | 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 4th gear. |
• | Open lock up clutch |
• | The hold 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 P1884 sets, the possible cause of the fault could be the TCM.
Step | Action | Value(s) | Yes | No |
---|---|---|---|---|
1 | Did you perform the Diagnostic System Check - Automatic Transmission? | -- | Go to Step 2 | |
2 |
Was a condition found? | -- | 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. Refer to Transmission Control Module Replacement . 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 | Repair and/or replace the transaxle, as necessary. Did you complete the repair? | -- | Go to Step 8 | -- |
8 |
Are there any DTCs displayed that have not been diagnosed? | -- | Go to Step 2 | System OK |