GM 22 Throttle Position Sensor Error Signal Low
How to read it
Code 22 reads as 2 flashes, pause, 2 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 22 mean?
Throttle Position Sensor Error Signal Low
Common causes of 22
- Open TPS signal wire or unplugged sensor connector
- Sensor ground circuit open
- Failed sensor with low output across the sweep
- Short to ground in the signal wiring
How to fix 22
- Read TPS voltage through the ALDL port and confirm it stays near zero
- Inspect the connector and ground splice for opens and corrosion
- Sweep the throttle while watching voltage for dropouts
- Test reference voltage at the sensor before condemning it
- Replace the sensor only after power and ground test good
Source
Qualified source review
Sources and review
Review: qualified. Read the source limits below.
- GM and Chevrolet OBD1 Trouble Codes (ALDL Fault Code List)
live reference page (troublecodes.net)
Supports: code identity and GM meaning
Fetched directly. Single publisher, so the record is qualified, not verified. Causes and check order are curator-written from the circuit the code names.
https://www.troublecodes.net/gm/
Last updated 2026-09-19.
Report a correction for 22. Include your vehicle, the issue and a source if you have one.