HVAC System LED Flash Code Information
Flash codes are communicated via a blinking LED located near the connectors on the HVAC control module. The blinking LED can be seen from under the instrument panel on the driver side (without disassembly). When the ignition is cycled on, the module immediately confirms the software level by flashing a 3 digit code. Each digit can be 0 - 9 and is blinked two times during an ignition cycle.
Diagnostic flash codes are 4 digit codes where each digit can be 0 - 4. Numbers 1 - 4 are indicated by a fast series of consecutive blinks (dots). Zeros are represented by long blinks (dashes). If there is an error condition, the module will blink a 4 digit diagnostic code typically for as long as the error condition exists. See the following table for blink behavior versus code digit value.
| Digit Value | LED Behavior |
|---|---|
| 0 | One Long Blink (dash) |
| 1 | One Short Blink (dot) |
| 2 | 2 short consecutive blinks (2 dots) |
| 3 | 3 short consecutive blinks (3 dots) |
| 4 | 4 short consecutive blinks (4 dots) |
The module can blink multiple 4 digit codes if multiple error conditions exist. After all codes are blinked, there will be a long pause and this list of active codes will be repeated until all codes are cleared. The blank time between blinks gets progressively longer for the following conditions:
- Between blinks of a digit.
- Between digits.
- Between codes.
- Between repeating code list.
For a complete list of the HVAC System Flash Codes, Refer to: Climate Control System .