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Old 18th January 2017, 15:10   #1
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Question Captiva AT: Losing power at high altitude

Hello members,
Recently I have been to Ladakh on my beloved CHEVROLET CAPTIVA LTZ AWD. On the way to high passes (Khardungla pass, Changla pass etc.), my car`s Automatic Transmission keeps on loosing power. Fortunately, I figured out the way to handle this situation by harnessing & releasing power through acceleration in AT mode. Any expert can explain the cause of power lack in AT. Kindly participate so that I can explain the problem more clearly.
Advance thanks.
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Old 18th January 2017, 15:49   #2
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Default Re: Automatic transmission loosing power on high altitudes

Not an expert. Let me try:
Higher Altitude=Rarefied Air
Rarefied Air=Less Oxygen
Less Oxygen=Insufficient combustion
Insufficient combustion=Less power

Stay in lower gears(going to the M mode) and keep your filters clean. Leave the ECU to manage the rest.
Experts, please add in if I have missed something.
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Old 18th January 2017, 16:12   #3
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Default Re: Automatic transmission loosing power on high altitudes

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Originally Posted by aqualeo2040 View Post
Not an expert. Let me try:
Higher Altitude=Rarefied Air
Rarefied Air=Less Oxygen
Less Oxygen=Insufficient combustion
Insufficient combustion=Less power

Stay in lower gears(going to the M mode) and keep your filters clean. Leave the ECU to manage the rest.
Experts, please add in if I have missed something.

Power from less oxygen makes sense and that's true, engine is only able to achieve power in the lower gears. But the issue is when in AT mode, ECU is unable to choose low gears. As there is an issue with M mode in my car, I have to harness the power in AT mode only & quickly release it on getting through high altitude passes. So what went wrong with AT or ECU?

PS: On plains, AT mode runs perfectly fine & uses lower gears on demand without any issue.

Last edited by GTO : 19th January 2017 at 10:12. Reason: Language
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Old 18th January 2017, 17:09   #4
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Could it be more due to the use of diesel in cold weather rather than anything else ?
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Old 18th January 2017, 19:22   #5
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Default re: Captiva AT: Losing power at high altitude

Quote:
Originally Posted by SYSTEMIZED View Post
Hello members,
Recently I have been to Ladakh on my beloved CHEVROLET CAPTIVA LTZ AWD. On the way to high passes (Khardungla pass, Changla pass etc.), my car`s Automatic Transmission keeps on loosing power. Fortunately, I figured out the way to handle this situation by harnessing & releasing power through acceleration in AT mode. Any expert can explain the cause of power lack in AT. Kindly participate so that I can explain the problem more clearly.
Advance thanks.
What do you mean harnessing and releasing power?

Seems like the engine is producing less power because of the high altitude.

Have you checked your air filter?
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Old 18th January 2017, 19:59   #6
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Default re: Captiva AT: Losing power at high altitude

Quote:
Originally Posted by SYSTEMIZED View Post
Hello members,
Recently I have been to Ladakh on my beloved CHEVROLET CAPTIVA LTZ AWD. On the way to high passes (Khardungla pass, Changla pass etc.), my car`s Automatic Transmission keeps on loosing power. Fortunately, I figured out the way to handle this situation by harnessing & releasing power through acceleration in AT mode. Any expert can explain the cause of power lack in AT. Kindly participate so that I can explain the problem more clearly.
Advance thanks.
I know 2 other people apart from you who drove their Captiva AT AWD to Spiti/Ladakh and faced the same issues you have mentioned. The only workaround is to revv the car in neutral and slam it into D. It is a problem with all Captiva AT cars, not specific to your car. Unfortunately there is no low range gearing reduction either to get the car moving.

Similarly Outlander too faces such issues at Altitude.

Last edited by .anshuman : 18th January 2017 at 20:00.
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Old 19th January 2017, 10:44   #7
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Default Re: Captiva AT: Losing power at high altitude

Please check your air filter. Due to duty environment in Ladakh, the air filter get clogged easily. Rarefied air doesn't help either. IIRC, we changed the air filter of my duster near Chang La last year. The difference in power delivery was substantial.

You can also check on any performance filter with better airflow for these trips.

Regards,

Pawan
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Old 19th January 2017, 14:00   #8
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Default Re: Captiva AT: Losing power at high altitude

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Originally Posted by Akshay1234 View Post
What do you mean harnessing and releasing power?

Seems like the engine is producing less power because of the high altitude.

Have you checked your air filter?
I mean rev up the car in "P" mode and shifting into "D" mode to get instant acceleration.

Quote:
Originally Posted by .anshuman View Post
I know 2 other people apart from you who drove their Captiva AT AWD to Spiti/Ladakh and faced the same issues you have mentioned. The only workaround is to revv the car in neutral and slam it into D. It is a problem with all Captiva AT cars, not specific to your car. Unfortunately there is no low range gearing reduction either to get the car moving.

Similarly Outlander too faces such issues at Altitude.
That's a really useful piece of information. I need to clear one thing, will rev up the car from "N" or "P" mode then shifting to "D" do any damage to transaxle or AT?

Last edited by SYSTEMIZED : 19th January 2017 at 14:04.
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Old 19th January 2017, 15:05   #9
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Default Re: Captiva AT: Losing power at high altitude

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Originally Posted by SYSTEMIZED View Post
That's a really useful piece of information. I need to clear one thing, will rev up the car from "N" or "P" mode then shifting to "D" do any damage to transaxle or AT?
When you are stuck at a remote place, will you really care about long term damage? I can guess this will damage, if done repeatedly over long time, but this is the only workaround except for getting the car towed.

Other than this, keep momentum when climbing, use manual mode to keep revs above 2k, do not stop on incline, keep gap with other vehicles.

Also the rear suspension in Captiva is also fragile, the auto leveling system gets damaged easily. Not a car I would recommend for expedition usage.
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Old 19th January 2017, 15:55   #10
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Default Re: Captiva AT: Losing power at high altitude

Quote:
Originally Posted by SYSTEMIZED View Post
Hello members,
Recently I have been to Ladakh on my beloved CHEVROLET CAPTIVA LTZ AWD. On the way to high passes (Khardungla pass, Changla pass etc.), my car`s Automatic Transmission keeps on loosing power. Fortunately, I figured out the way to handle this situation by harnessing & releasing power through acceleration in AT mode. Any expert can explain the cause of power lack in AT. Kindly participate so that I can explain the problem more clearly.
Advance thanks.
Pardon me for a noob question.
Would resetting the ECU at such altitudes help. Just disconnect the battery for 15 mins and plug in again. I guess, this will force the ECU to adjust according to available oxygen levels.
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Old 19th January 2017, 15:59   #11
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Default Re: Captiva AT: Losing power at high altitude

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Originally Posted by gypsyFreak View Post
Pardon me for a noob question.
Would resetting the ECU at such altitudes help. Just disconnect the battery for 15 mins and plug in again. I guess, this will force the ECU to adjust according to available oxygen levels.
Haven`t thought of such tinkering but it can be a possible solution. Let`s see what experts say about this.
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Old 19th January 2017, 17:14   #12
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Default Re: Captiva AT: Losing power at high altitude

As far as I can see, the same thing happens in quite a few MT vehicles also, small or big in those rarefied regions, though the extent and its feel to the driver differs as per the car and its mechanicals. Additionally, MT vehicles have better control on the transmission to downshift and revv so the extent and working is different than AT.

You may have to just adjust to Altitude Adjustment driving habits, as per the car. As Anshuman says above, revv to keep up to 2000 and keep the momentum.

I am sure, Captiva AT must be having Drive mode manual overrides, +/- in Drive 'D' mode.

The best you may be able to do whenever this situation occurs is, shift to manual control, shift to lower gear as much as possible as per situation, M3 -> M2 -> M1 and revv at the same time to try keep above 1500-2000 in the gear whichever is suitable for Captiva and keep the momentum up the hill. However, AT mechanisms as per setup, automatically detect upshift to the higher gear as engine is revved more and also how Captiva's AT is responsive to this is doubtful. But this is one combination you may have at your disposal that will not hurt the transmission of the AT.
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Old 20th January 2017, 17:36   #13
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Default Re: Captiva AT: Losing power at high altitude

Quote:
Originally Posted by SYSTEMIZED View Post
Hello members,
Recently I have been to Ladakh on my beloved CHEVROLET CAPTIVA LTZ AWD. On the way to high passes (Khardungla pass, Changla pass etc.), my car`s Automatic Transmission keeps on loosing power. Fortunately, I figured out the way to handle this situation by harnessing & releasing power through acceleration in AT mode. Any expert can explain the cause of power lack in AT. Kindly participate so that I can explain the problem more clearly.
Advance thanks.
I used to experience similar loss of power in my Cruze LTZ MT when I used to drive up to Ooty. Infact almost every time I have driven up to Ooty I have felt a significant loss of power from almost the same location (read altitude). I estimate at an altitude of about 1800 ~ 2000 metres (I know it sounds really low to affect oxygen levels). I drive a lot in the lower regions of the Nilgiris (Kotagiri and Coonoor) which is at an altitude of about 1600 ~ 1700 metres and the car behaves normally as it does in the plains. However, each time I have climbed higher towards Ooty I have experienced this reduced power delivery. The older Captiva and Cruze shared the same engine.
Contrary to what you have mentioned, I do not feel it has anything to do with the automatic transmission and has more to do with the ECU not coping with the reduced oxygen levels at that altitude.
Like suggested by gypsyFreak, I think resetting the ECU at that altitude to allow it to adjust to the ambient atmosphere might do the trick.
Further, I think it is always better to keep an automatic transmission on manual mode (I dont know if your Captiva has a manual mode) in the hills as you have more control over the gear shifts.
I now drive the new Endeavour 3.2 automatic and I have realized that manual is the way to go when driving uphill and more importantly, downhill.
My two cents.

Last edited by SCORPION : 20th January 2017 at 17:44.
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Old 20th January 2017, 18:25   #14
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Default Re: Captiva AT: Losing power at high altitude

Loss of power usually happens at 4000+ meters (At most of the passes of Ladakh). One thing I forgot to mention here that "SERVICE LAMP" light comes on whenever I travel on high altitudes and AT started losing power.
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Captiva AT: Losing power at high altitude-imag2129.jpg  

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Old 20th January 2017, 20:11   #15
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Default Re: Captiva AT: Losing power at high altitude

Quote:
Originally Posted by SCORPION View Post
I used to experience similar loss of power in my Cruze LTZ MT when I used to drive up to Ooty.
Problems at Ladakh pass altitudes are understandable (not excusable, mind you), but problems in Ooty is ridiculous.
If this can be corroborated by others, needs to be taken with the manufacturer.

Regards
Sutripta
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