Circuit Description
When a gear is commanded ON, the vehicle speed to input shaft speed ratio is
monitored to assure the correct gear ratio is achieved. Shift solenoid 3 performance
indicates that another gear was commanded, but the actual ratio driving the vehicle
is equal to 3rd gear. This is a calculated value, input shaft speed/vehicle
speed equals gear ratio. Third gear clutch is turned OFF by grounding circuit 1223
at the PCM.
Conditions for Setting the DTC
DTC P0782 is set when flagged on when the PCM has detected the following conditions
for more than 3 seconds twice per ignition cycle:
| • | First gear is commanded by the PCM. |
| • | No noise on the input shaft or vehicle speed signals. |
| • | Vehicle speed is greater than 5 km/h (3 mph). |
| • | Input shaft speed is greater than 224 RPM. |
| • | The speed ratio across the torque converter, engine speed versus input
speed, is less than 180. A speed ratio of 255 would be TCC on. |
| • | The PCM calculated engine load value is greater than 200. |
| • | The input shaft to vehicle speed ratio equals 3rd gear. |
Test Description
Numbered steps below refer to numbered steps on the chart.
- Check for DTCs P0761, P0763, or P0764. They must be eliminated
first as a possible cause of DTC or DTC P0782.
Important: To check the solenoid operation, command
the solenoid quick test using the scan tool.
- Check the solenoid operation. Use the solenoid quick check in the test section.
Listen and compare the noise of the 3rd gear solenoid to that of the other
solenoids. The noise should be similar.
- The problem could be a mechanical failure. This step begins the internal
diagnosis. The air check procedure is in Test Section Diagnosis found at the end of
the DTC charts.
- Cross leaks to/from 3rd clutch oil passages can cause 3rd clutch
to be on at all times. The possible leak due to seals, gaskets, porosity, etc.
- As air pressure is applied and released, the clutch plates should also
apply and release. If the clutch plates are moving normally, the problem is probably
in the valvebody. If clutches are not moving correctly, the problem is in the end
cover or an internal transaxle problem exists.
Repair Verification
Monitor the DTC menu Code Status for Pass Since Code Clear and Pass This Ignition
Cycle. When both have passed, the repair is verified.
Criteria for pass:
| • | Power is present at the solenoids and no active faults exist for this
solenoid. |
Diagnostic Aids
This DTC may set or intermittent 3rd gear starts may be caused by a poor
electrical connection at either the PCM, solenoid connector plate, or UHJB terminals.
Wiggling the connectors while performing a solenoid quick test may help isolate the
problem area.
This DTC will probably be accompanied by DTC P0732 and DTC P0741.
