[5th Gen : 08+]: Is HVAC Calibration Required After Replacing Actuator
#1
06-06-2019, 10:24 AM
Is HVAC Calibration Required After Replacing Actuator
Must you have your HVAC calibrated after replacing an actuator? Last week a clicking sound started coming from the rear AC on my 2013 SXT plus I was able to determine it was coming from the mode select actuator rather than heat actuator every time switching from floor to headliner mode an annoying clicking sound can be heard. The actuator still works as you can feel the air being switch from the floor to the headliner. I ordered a new OEM 68299450AA actuator just received it got all the tools to take the trim off the rear luckily the faulty actuator is at the top I plan to change it this weekend. I don't have a scan tool I was wondering is it necessary to have the HVAC calibrate at the dealer to assure that every actuator are operating properly
#2
06-06-2019, 06:41 PM
#4
06-09-2019, 07:59 AM
Yesterday I decided to change out my faulty blend door actuator after removing the trim and upon close inspection I notice the actuators had only 2 wires. Being an electrician by trade with a lot of control and building automation experience I realize this was noting more than an output device receiving a signal such as a damper motors, zone valves or VAV boxes these motors have built in potentiometers to determine their position. They don't have a power off position they need an input signal to move so once a set position is chosen the actuator won't move till it receives a different input signal.
There's no need to disconnect the battery just unplugged the blend door actuator at set position and replace. The blend door actuators are made to only fit in a certain position you might have to fit in the spline and rotate the whole actuator assembly to line up properly with the mounting holes.
Checked operation of mode door it worked perfectly open fully for headline mode closed fully for floor mode and stop in the middle for bi-level mode. The input signal is sent from the climate control head signal is likely 0-5 vdc. The CC is the smart device that reads the resistance of potentiometer and determines at what position each actuators is then determines what polarity to signal to open or close the actuators.
There's no need to disconnect the battery just unplugged the blend door actuator at set position and replace. The blend door actuators are made to only fit in a certain position you might have to fit in the spline and rotate the whole actuator assembly to line up properly with the mounting holes.
Checked operation of mode door it worked perfectly open fully for headline mode closed fully for floor mode and stop in the middle for bi-level mode. The input signal is sent from the climate control head signal is likely 0-5 vdc. The CC is the smart device that reads the resistance of potentiometer and determines at what position each actuators is then determines what polarity to signal to open or close the actuators.
Last edited by Mopar340; 06-09-2019 at 09:00 AM.
#5
06-09-2019, 09:32 AM
You’re not wrong on the operation of the actuator, but there’s plenty of reasons to disconnect the negative battery cable while doing so.
1) It will clear any DTC’s that were stored as a result of the faulty actuator. Some control modules won’t allow operation at all while codes are present.
2) Depending on the requested command and the position of the actuator when it failed, the control module may try to complete the command when the key is turned on, resulting in a false range of motion and requiring a recalibration anyway.
3) It ensures the module is shut down during the replacement and prevents potential damage in case of an accidental short to voltage/ground situation. The actuator you replaced only had 2 wires, but some have 5 or 6 and a constant power feed as long as the module is on. With the battery hooked up, the module will stay on even if the key is off because the data network keeps it active for a time (varies).
4) Depending on what you have to remove to access the actuator (such as a rear trim panel that covers floor to ceiling) there’s potential for the air bags to be activated if the wiring is somehow damaged during removal or installation. Just as with the HVAC module, disconnecting the battery ensures the air bag module is shut down to prevent this.
These are all general statements not specific to your van - I’d have to read up on your van to know for sure which ones apply - but they cover enough automobiles today that (to me) it’s worth taking an extra minute to disconnect the battery and make sure they don’t happen.
1) It will clear any DTC’s that were stored as a result of the faulty actuator. Some control modules won’t allow operation at all while codes are present.
2) Depending on the requested command and the position of the actuator when it failed, the control module may try to complete the command when the key is turned on, resulting in a false range of motion and requiring a recalibration anyway.
3) It ensures the module is shut down during the replacement and prevents potential damage in case of an accidental short to voltage/ground situation. The actuator you replaced only had 2 wires, but some have 5 or 6 and a constant power feed as long as the module is on. With the battery hooked up, the module will stay on even if the key is off because the data network keeps it active for a time (varies).
4) Depending on what you have to remove to access the actuator (such as a rear trim panel that covers floor to ceiling) there’s potential for the air bags to be activated if the wiring is somehow damaged during removal or installation. Just as with the HVAC module, disconnecting the battery ensures the air bag module is shut down to prevent this.
These are all general statements not specific to your van - I’d have to read up on your van to know for sure which ones apply - but they cover enough automobiles today that (to me) it’s worth taking an extra minute to disconnect the battery and make sure they don’t happen.
#6
06-11-2019, 10:14 AM
You’re not wrong on the operation of the actuator, but there’s plenty of reasons to disconnect the negative battery cable while doing so.
1) It will clear any DTC’s that were stored as a result of the faulty actuator. Some control modules won’t allow operation at all while codes are present.
2) Depending on the requested command and the position of the actuator when it failed, the control module may try to complete the command when the key is turned on, resulting in a false range of motion and requiring a recalibration anyway.
3) It ensures the module is shut down during the replacement and prevents potential damage in case of an accidental short to voltage/ground situation. The actuator you replaced only had 2 wires, but some have 5 or 6 and a constant power feed as long as the module is on. With the battery hooked up, the module will stay on even if the key is off because the data network keeps it active for a time (varies).
4) Depending on what you have to remove to access the actuator (such as a rear trim panel that covers floor to ceiling) there’s potential for the air bags to be activated if the wiring is somehow damaged during removal or installation. Just as with the HVAC module, disconnecting the battery ensures the air bag module is shut down to prevent this.
These are all general statements not specific to your van - I’d have to read up on your van to know for sure which ones apply - but they cover enough automobiles today that (to me) it’s worth taking an extra minute to disconnect the battery and make sure they don’t happen.
1) It will clear any DTC’s that were stored as a result of the faulty actuator. Some control modules won’t allow operation at all while codes are present.
2) Depending on the requested command and the position of the actuator when it failed, the control module may try to complete the command when the key is turned on, resulting in a false range of motion and requiring a recalibration anyway.
3) It ensures the module is shut down during the replacement and prevents potential damage in case of an accidental short to voltage/ground situation. The actuator you replaced only had 2 wires, but some have 5 or 6 and a constant power feed as long as the module is on. With the battery hooked up, the module will stay on even if the key is off because the data network keeps it active for a time (varies).
4) Depending on what you have to remove to access the actuator (such as a rear trim panel that covers floor to ceiling) there’s potential for the air bags to be activated if the wiring is somehow damaged during removal or installation. Just as with the HVAC module, disconnecting the battery ensures the air bag module is shut down to prevent this.
These are all general statements not specific to your van - I’d have to read up on your van to know for sure which ones apply - but they cover enough automobiles today that (to me) it’s worth taking an extra minute to disconnect the battery and make sure they don’t happen.
Unlike popular belief disconnecting the battery will not clear any stored codes in OBD-2 memory they must be erased with a scan tool. OBD-2 climate control codes I believe only monitors crucial points like refrigerant pressures, compressor operation evaporator and condenser temp.
Climate control unit has to read the position of every actuator at every start up it doesn't matter when the actuator failed or when it's replaced at the very next ignition on cycle the CCU will read the position of new actuator before initiating any command. The actuators only fit one way the spline is keyed they're impossible to be installed in the wrong position.
Everything is made out of plastic even the connector it's a plastic female so the wires and pins are insulated impossible to short out
The trim panel which needed to be removed didn't have any air bag component in them and a short will not cause the air bags to go off I know this for a fact my car had a shorted clock spring which is part of the air bag circuitry it caused an air bag warning light along with steering warning indication had to bring it to the dealer to be scanned the short cause the SRS unable to read the resistance of the air bag and the position of the steering wheel.for the SAS.