TATA PUNCH-SERVICE MANUAL

HVAC 12 7. WORKING / FUNCTION OF ETC (ELECTRON- IC TEMPERATURE CONTROLLER) The HVAC control panel consists of 8 Push buttons, 1 rotary knobs and 1 Rocker switch that can be used to set the required temperature/Air flow/comfort in- side the cabin. In addition to this the control panel also acts as a control unit for the HVAC system in which all the software calibrations are embedded. A. PROCEDURE OF AUTO LEARNING: 1. With every replacement of ETC Panel calibration shall be initiated automatically. 2. At first ignition ON (After ETC panel replacement) all DC motors will automatically calibrated. While calibration is running AC LED will keep blinking. Once calibration completed AC LED will stop blinking and will restore its previous setting. 3. Turn Off the ignition and Wait for 6 Sec to store calibrated parameter into EEPROM. 4. After completing above mentioned process of Auto Calibration, turn ON ignition. 5. Wait for 5 sec. 6. If Recirc LED does not blink that means no fault present and calibration is done. 7. If Recirc LED do blink that means fault is there and need to enter in Diagnostics mode to check. 8. For Blinking Pattern and timing refer Failure indi- cation during normal mode section . 9. After entering in Diagnostic mode if Leg, Recirc and First Temp Blue LED is blinking that signifies Calibration is failed for respective motor. 10.For Blinking Pattern and timing refer Blinking code display section. 11.If Calibration get failed then Auto Calibration will try calibrating motors at 20 consecutive ignition cycle. Once calibration is successful, then Cali- brated parameters get stored in EEPROM at Ignition OFF. NOTE: Make sure Park lamp is OFF to enter Panel in Sleep state. B. FAILURE INDICATION DURING NORMAL MODE: After every ignition cycle detects the failure (one time) after 5 sec from power up, ETC will indicate the user by blinking the RECIRC blink code in following sequence. This is to inform user about some fault in the system and he should drive to service station to diagnose the fault. 1. Right after ignition On, Blink the RECIRC LED 2 times with 1 sec ON and 1 sec OFF. 2. RECIRC LED is OFF for 2Sec. 3. Repeat the step i and ii for 2 times. 4. Total 10sec time after IGN ON to indicate the fault. Blink RECIRC LED 2Times 1sec ON / 1sec OFF 2Sec OFF Blink RECIRC LED 2Times 1sec ON / 1sec OFF Blink Code during Normal Mode C. MANUAL CALIBRATION OF DC MOTORS: If Auto calibration is not successful there is a provi- sion of maual calibration of motors. After Ignition ON Manual calibration will be per- formed with following key combination in Normal Mode. 1. Blower is at Level 1. 2. Mode selection knob is at "LEG" position. 3. Temperature selection knob is at max hot posi- tion. 4. Recirc key pressed more than 5 seconds. While calibration is running AC LED will keep blink- ing. Once calibration completed AC LED will stop blinking and will restore its previous setting. NOTE: Turn Off the ignition and Wait for 6 Sec to store cali- brated parameter into EEPROM. D. ENTER DIAGNOSTICS MODE: The special diagnostics mode shall be invoke using following sequence: 1. During first 15 sec from power up. With IGN ON, Put blower at level 1 and Temp is at max hot. 2. Keep the OFF button pressed for more than 5 sec. 3. Face mode LED will get turn ON which will indi- cate panel entered in Diagnostics Mode. NOTE: Panel will not enter in diagnostic mode in over and under voltage condition.