3 captured repliesDiscussion pagination complete · Source accounts, not a confirmed diagnosis
THIS DISCUSSION / SOURCE-DERIVED OVERVIEW
Discussion summary
YOUR RESEARCHHeater/AC temp controls not fine tunable
Leading reported evidence
Replace outflow temperature
Suggestion or failed attempt
No successful repair reported for this finding.
0
Reported fixes
0
Unsuccessful attempts
1
Discussions
Read evidence and context
Explicit resolution reports before identified causes, performed actions and suggestions. Within each level, matching component labels precede direct query mentions and inherited thread context; successful versus unsuccessful discussion counts, owner confirmations and independent discussion support determine order. This is not a probability of success.
Discussions that contain suggestions
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Suggestion
So, if you're at 72F and the system has long since "settled" at that cabin temperature and you change the setpoint to say, 78F, it might take a few minutes for the system to fully react, and it will NOT dramatically change the outflow temperature.
Leading evidence: 'Replace outflow temperature' (no explicit attributable resolution; this is a reported action or suggestion). Across 1 matching discussions, The most frequently discussed action is 'Replace outflow temperature' (1 discussions). For that action, 0 discussions report a resolution and 0 report an unsuccessful attempt. No action has an explicit, attributable resolution report under the current rules. These are forum reports and suggestions, not a confirmed diagnosis.
Source reports, not a diagnosis or a success probability. Counts refer to discussions and can overlap.
Explicit resolution reports before identified causes, performed actions and suggestions. Within each level, matching component labels precede direct query mentions and inherited thread context; successful versus unsuccessful discussion counts, owner confirmations and independent discussion support determine order. This is not a probability of success.
Discussions that contain suggestions
1
0 original-poster resolution reports. Counts can overlap; they are not unique people or a success rate.
0 discussions have direct query context; 0 report a fix in that context. Other evidence may inherit the discussion’s subject.
Suggestion
So, if you're at 72F and the system has long since "settled" at that cabin temperature and you change the setpoint to say, 78F, it might take a few minutes for the system to fully react, and it will NOT dramatically change the outflow temperature.
These are separate views of the same evidence. Frequency alone does not establish a fix, and these counts must not be added together.
Replace outflow temperature
No successful repair reported for this finding.
0
Reported fixes
0
Unsuccessful attempts
1
Discussions
Read evidence and context
Discussions that contain suggestions
1
0 original-poster resolution reports. Counts can overlap; they are not unique people or a success rate.
0 discussions have direct query context; 0 report a fix in that context. Other evidence may inherit the discussion’s subject.
Suggestion
So, if you're at 72F and the system has long since "settled" at that cabin temperature and you change the setpoint to say, 78F, it might take a few minutes for the system to fully react, and it will NOT dramatically change the outflow temperature.
0 original-poster resolution reports. Counts can overlap; they are not unique people or a success rate.
0 discussions have direct query context; 0 report a fix in that context. Other evidence may inherit the discussion’s subject.
Suggestion
So, if you're at 72F and the system has long since "settled" at that cabin temperature and you change the setpoint to say, 78F, it might take a few minutes for the system to fully react, and it will NOT dramatically change the outflow temperature.
Counts describe captured discussions, not unique people or a diagnosis. Author identities are not reliably stored. Exact duplicate evidence is counted once across matching discussions; one discussion counts at most once per action/state. Multiple repairs reported together remain a combination. Suggestions and failed attempts do not establish a fix. Matches cover whole discussions and can include related faults, model variants and incomplete threads.
3 eligible posts · 0 unverified posts · 1 discussions match the subject in their title or opening post.
Rennlist: 1 discussions
0 evidence records excluded for query context · 0 excluded by outcome qualification · 0 adjusted by outcome qualification.
0 acknowledgements have no verified action link; they do not establish a repair result.
Generation: 20261026T200546Z · outcome-qualification-6. Deterministic extraction; no AI model inference. How we use sources
My in-law's 2003 996 HVAC controls don't seem to like small changes in temp setting. Note that they've had this issue for a while, but now my wife (for mother's day) asked me to help them fix the freakin thing.
So here's what we have:
1. Fans work in all steps
2. AC blows cold, heater blows hot
3. But it doesn't seem to like small changes in temp setting. I.e. - If I move the HVAC from 70 to 76F, I don't necessarily feel a difference on hotness or coldness of the blower.
4. If I move to 86F (it actually says HI for hi-temp), then it gets *really* hot. If I move to full cold, it gets really cold.
5. If I move to 85 or 83, it's still hot, but barely.
So I am thinking that it's some sort of cabin temperature sensor that may be dirty or "flap" that needs lubricating or something.
Can anyone make a suggestion?
Does his ignition key work smoothly? AC is one of the things that go haywire when the key starts to misbehave.
Have they had any foam, black bits, come out of the vents? If so the foam seals might be deteriorating allowing leakage around the mixing flap(s). You have to pull the battery and heater core to get at the flap. There is a DIY around here somewhere on rebuilding the seals.
http://www4.rcf.bnl.gov/~nieuwhzs/98...p%20Repair.pdf
Pretty sure the sensor lives under the small round "speaker" looking grill in front of the passenger. Maybe pull it out and inspect. Someone might pipe in with Ohms values?? Fuses? C7, D6, E7 all have something to do with climate control - AC.
SOP
The 996 A/C has 2 extra control inputs, an OAT (Outside Air Temperature) sensor in the front "bumper" passenger side, and a "sun" radiation sensor at the interior base of the windshield.
The design goal is such that the system will moderate the airflow in small increments in order to not unduly discomfort the driver/passenger.
On a HOT day with the setpoint at say, 72F, once the cabin atmosphere begins to approach that "target" the system will begin the moderation process. The outflow air temperature will begin to rise to within just a few degrees of your setpoint, the blower speed will decline, and all airflow outlets will begin opening, footwell, dash,...AND windshield.
In BRIGHT sunlight and HIGH OAT the system will be biased toward cooler airflow overall vs a coolish overcast day.
I find that with these NEW systems, Lexus LS series, for instance, if you want QUICK cooldown or warmup then you MUST interact with the system, MAX cooling/heating(***) until the cabin temperature nears your comfort level.
So, if you're at 72F and the system has long since "settled" at that cabin temperature and you change the setpoint to say, 78F, it might take a few minutes for the system to fully react, and it will NOT dramatically change the outflow temperature.
*** ALL sensor inputs are ignored.
This is a source reference. Confirm exact model applicability in the original material.
