GM 93 Transmission Pressure Control Solenoid Circuit Error
How to read it
Code 93 reads as 9 flashes, pause, 3 flashes on the check-engine light. Jump terminals A and B on the ALDL connector with the key off, then turn the key on with the engine off and count the check-engine flashes.
New to flash codes? The How to Read GM OBD-I Codes with a Paperclip walks through the test and what the numbers mean. The general OBD-I guide covers the rest.
What does GM code 93 mean?
Transmission Pressure Control Solenoid Circuit Error
Common causes of 93
- Failed pressure control solenoid
- Open or shorted solenoid wiring
- Stuck pressure regulator valve
- Low fluid or clogged filter
How to fix 93
- Read codes with an ALDL scan tool
- Check fluid level and condition
- Test solenoid resistance at the trans connector
- Inspect the internal harness for rubs
- Check line pressure against spec if equipped
- Replace the solenoid or harness as tests show then retest
Source
Qualified source review
Sources and review
Review: qualified. Read the source limits below.
- GM OBD1 trouble codes, model and year page
live reference page (troublecodes.net)
Supports: code identity and GM meaning
Fetched directly from the linked model page. Single publisher, so the record is qualified, not verified.
https://www.troublecodes.net/GM/gm-93-94-5-7l-vin-p/
Last updated 2026-09-19.
Report a correction for 93. Include your vehicle, the issue and a source if you have one.