Diesel Data: Automotive Repair

Transmission Control System

Name
Code No. 21 pressure switch circuit

Description
Pressure switch error count must equal 255.

Probable cause
- Low/High fluid level in transaxle
- Malfunction of pressure switch assembly
- Harness or connector between OD pressure switch and TCM open or short-circuited
- Malfunction of TCM
- Internal transaxle problem





Diagnosis