| Subject: | Information on Seki Automatic Transaxle Shift Concerns |
| Models: | 1987-92 Chevrolet Sprint |
This information provides additional diagnostics to aid in diagnosing
shift concerns on the Seki automatic transaxle and identifies the most common
failure types resulting in any of the following shift complaints:
The most common failure types are the Vehicle Speed Sensor (VSS)
in the transaxle, shift solenoids, valve body or related wiring.
Important: During Preliminary inspection, note any installed aftermarket accessories
and beware that certain aftermarket accessories or improper installation techniques
may also cause these symptoms.
To help isolate if the fault is the external wiring or within the transaxle,
perform the following procedure:
- Disconnect the electrical connector on the transaxle (connector
is located beside the battery).
- Road test and manually shift the transaxle.
| • | If transaxle shifts properly, suspect the transaxle external wiring
and verify electrical connections |
| • | If transaxle does not shift properly, suspect an internal mechanical
failure such as a valve body or other failed internal component |
The most common "external" type failures for the following
conditions are:
No Up-Shift / 1st Gear Only
Check VSS in the transaxle.
3rd Gear Start
| • | Check shift solenoids and TPS for proper operation and readings. |
| • | Verify wiring from PCM to ATCM (Automatic Transmission Control
Module). |
| • | If all checks good the VSS in the transaxle may be the cause. |
