With Scan Tool

The Tech 1 can also be used to display HVAC DTCs, clear HVAC DTCs and display HVAC data.

Install the Tech 1 using mass storage cartridge #3000003 to the DLC. Select HVAC system under the appropriate "body option" selection in the cartridge. Below is a list of HVAC data that can be read in the Tech 1.

HVAC Prog # 0-255
HVAC Air Delivery Mode See table

Blower Duty Cycle 0%-50%
A/C Comp On Time A/D Counts
Mix Door Com 0-255
Mix Door Act 0-255

In-car Air Temp (Temp display in) F°/C°
Outside Air Temp (Temp display in) F°/C°

Sun Load Input A/D counts

Mix Full Cold 0=No 1=Yes
Mix Full Hot 0=No 1=Yes

HVAC DTCs in the Tech 1 will display as a three digit number. The H-A/C control HVAC DTC 01 (current) [DTC 101 (history)] will display in the Tech 1 as 001C (current) and DTC 001H (history). The remaining HVAC DTCs will display in a like manner. Looking at other systems on CKT 800 (with a scan tool) and returning to the "HVAC" selection can cause an HVAC DTC 26 to set in the H-A/C control. When diagnosing an HVAC DTC 26, clear the DTC and check for HVAC DTCs again.