DTC 7 - Zone/Driver Actuator Did Not Reach Cold Stop

DIAGNOSTIC TROUBLE CODE 7 - ZONE/DRIVER ACTUATOR DID NOT REACH "COLD" STOP
When the HVAC Control Module calibrates the Zone/Driver Door Actuator, it moves the actuator toward the HOT position and then toward the COOL position. In the COOL position, circuit C102 of the 21 pin connector should have a value of about 0.6 to 1.2 volts. When the actuator does not reach the COOL position, DTC 7 sets.

Detection
When the voltage at C102 is greater than 2.0 volts, the DRB III will display the DTC.

Possible Causes
- Zone/Driver Door reaches the COLD position and does not respond to changes in control panel settings.
- Zone/Driver Feedback Signal circuit is SHORTED to 5 volts.
- Zone/Driver Actuator is stuck.
- Zone/Driver Door is stuck.
- Zone/Driver Door Actuator Driver circuit is OPEN.
- Zone/Driver Door Actuator Driver circuit is SHORTED to ground. Diagnostics begin momentarily and then STOP with NO LED's until the short is removed, and then both WIPE and INTERMITTENT LED's flash simultaneously.
- Zone/Driver Door Actuator gear is not properly connected.
- Front A/C only unit is installed in a Dual Zone Vehicle.

If there is COOL air flow (driver side Zone control), even though the DTC indicates that the actuator cannot reach the Cool position, there is a short to voltage in the Zone/Driver Feedback Signal circuit (the door is moved to the Cool position, attempting to decrease the feedback voltage).

If the Zone/Driver Actuator fails in the Mid position, both DTC's 7 and 8 will be set.

If the Zone/Driver Door/Actuator fails in the Hot position and is blowing HOT air, DTC 7 is set.

Test Procedures
1. Check if the correct HVAC control module was used.
Disconnect the Actuator connector.
2. Using a voltmeter, measure between pins 1 and 5. If the voltage is not 12 volts + 1 volt, check the actuator driver circuits wiring for a short or open circuit. Measure the voltage between pins 2 and 4. If the voltage is less than 4 volts, check the 5 volt supply circuit. Measure the voltage between pins 3 and
4. If the voltage is less than 4.5 volts, check the actuator feedback circuit.
3. Remove actuator, and check if the gear pins are in the correct track on cam or if they are binding. If OK, go to Step 4. If not OK, repair as necessary.
4. Check for binding doors, if door are binding repair as necessary. If gears and door are OK, replace actuator.
5. Once repairs are completed repeat the Calibration Diagnostic and Cooldown test. Repeating the test is necessary to clear the fault codes.