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Porsche Club GB

'Fail Safe' mode?

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6 captured repliesDiscussion pagination complete · Source accounts, not a confirmed diagnosis
THIS DISCUSSION / SOURCE-DERIVED OVERVIEW

Discussion summary

YOUR RESEARCH'Fail Safe' mode?

Leading reported evidence

Disconnect battery

Performed · outcome unconfirmed

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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 performed work without a confirmed outcome
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Performed · outcome unconfirmed

Best bet is to see what happens now you have disconnected the battery, which will reset the DME.

'Fail Safe' mode?

Suggestion

It is normal for the alarm siren to go off when you disconnect the battery.

'Fail Safe' mode?
Frequently discussed work

Adjust unit

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Suggestion

This allow values to be stored for the throttle adjusting unit.

'Fail Safe' mode?
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Leading evidence: 'Disconnect battery' (no explicit attributable resolution; this is a reported action or suggestion). Across 1 matching discussions, The most frequently discussed action is 'Adjust unit' (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.

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1 matching discussions · 6 captured posts examined · 0 partial discussions

Compare 4 other evidence results

Disconnect battery, the alarm continued

Performed · outcome unconfirmed

No successful repair reported for this finding.

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Reported fixes
0
Unsuccessful attempts
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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 performed work without a confirmed outcome
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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.

Performed · outcome unconfirmed · Original poster

Also, when I disconnected the battery, the alarm continued for a few more seconds.

'Fail Safe' mode?

Adjust unit

Suggestion or failed attempt

No successful repair reported for this finding.

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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
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

This allow values to be stored for the throttle adjusting unit.

'Fail Safe' mode?

Check done

Suggestion or failed attempt

No successful repair reported for this finding.

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Reported fixes
0
Unsuccessful attempts
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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
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

If it happens again, the only thing to do is to get a diagnostic check done with a Porsche tester.

'Fail Safe' mode?

Disconnect battery and put it

Suggestion or failed attempt

No successful repair reported for this finding.

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Reported fixes
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Unsuccessful attempts
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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
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 · Original poster

I stopped and fired it up again, after which it got me about a mile up the road, when it happened again, but would not drive normally this time, so I limped home and have now disconnected the battery and put it on a proper charge.

'Fail Safe' mode?
Frequently discussed actions (10)

These are separate views of the same evidence. Frequency alone does not establish a fix, and these counts must not be added together.

Adjust unit

No successful repair reported for this finding.

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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

This allow values to be stored for the throttle adjusting unit.

'Fail Safe' mode?

Check done

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

If it happens again, the only thing to do is to get a diagnostic check done with a Porsche tester.

'Fail Safe' mode?

Disconnect battery

No successful repair reported for this finding.

0
Reported fixes
0
Unsuccessful attempts
1
Discussions
Read evidence and context
Discussions that performed work without a confirmed outcome
1
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.

Performed · outcome unconfirmed

Best bet is to see what happens now you have disconnected the battery, which will reset the DME.

'Fail Safe' mode?

Suggestion

It is normal for the alarm siren to go off when you disconnect the battery.

'Fail Safe' mode?

Disconnect battery and put it

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 · Original poster

I stopped and fired it up again, after which it got me about a mile up the road, when it happened again, but would not drive normally this time, so I limped home and have now disconnected the battery and put it on a proper charge.

'Fail Safe' mode?

Disconnect battery will

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

I think that disconnecting the battery will reset the adaption values regardless of the other conditions,

'Fail Safe' mode?

Disconnect battery, the alarm continued

No successful repair reported for this finding.

0
Reported fixes
0
Unsuccessful attempts
1
Discussions
Read evidence and context
Discussions that performed work without a confirmed outcome
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.

Performed · outcome unconfirmed · Original poster

Also, when I disconnected the battery, the alarm continued for a few more seconds.

'Fail Safe' mode?

Disconnect negative terminal of the battery

No successful repair reported for this finding.

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Reported fixes
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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

The way to stop it happening is to switch the ignition on, but don't start the engine, before you disconnect the negative terminal of the battery.

'Fail Safe' mode?

Replace bit )

No successful repair reported for this finding.

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Discussions that contain suggestions
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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

That's interesting Richard the conditions aren't listed in the 986 manual(least not in the battery change bit ).

'Fail Safe' mode?

Reset adaption values regardless of the other conditions

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

I think that disconnecting the battery will reset the adaption values regardless of the other conditions,

'Fail Safe' mode?

Reset dme

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

Best bet is to see what happens now you have disconnected the battery, which will reset the DME.

'Fail Safe' mode?
Coverage and how to read this overview

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.

6 eligible posts · 0 unverified posts · 1 discussions match the subject in their title or opening post.

  • Porsche Club GB: 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: 20261026T113718Z · outcome-qualification-6. Deterministic extraction; no AI model inference. How we use sources

POST 1 / ORIGINAL POSTEROriginal post

When I started my car about a month ago, after a break of a few weeks in the garage, it fired up OK, I left it to run for a few minutes, but when I went to drive it out of the garage it had no power and wouldn't rev over 1500, but continued ticking over just fine. I switched off and restarted, after which it was OK, took it for a quick blast, then parked it up again. Went to start it yesterday, but battery was too weak to fire it up, so I left it trickle charging for 24 hours. Fired up fine this afternoon (no lengthy warm-up) but as soon as I got it on to the road it lost power and went onto it's 1500 rev max. mode again. I stopped and fired it up again, after which it got me about a mile up the road, when it happened again, but would not drive normally this time, so I limped home and have now disconnected the battery and put it on a proper charge. Am I right in assuminmg that this is some kind of fail-safe mode for a low battery or such? If not, any ideas? All gauges showing correct figures. Also, when I disconnected the battery, the alarm continued for a few more seconds. How is this so?

POST 2Original post

It doesn't sound like normal behaviour to me, and I'm not aware of any fail-safe mode for the DME. Best bet is to see what happens now you have disconnected the battery, which will reset the DME. If it happens again, the only thing to do is to get a diagnostic check done with a Porsche tester. It is normal for the alarm siren to go off when you disconnect the battery. The siren has a backup battery built-in. The way to stop it happening is to switch the ignition on, but don't start the engine, before you disconnect the negative terminal of the battery.

POST 3 / ORIGINAL POSTEROriginal post

Many thanks Richard - fingers crossed about the battery.

POST 4Original post

Note on some models , not sure on 996 but definately on 986 when reconnecting the battery you should re-adapt the DME this is partly done by by switching on the igntion for 1 minute then switching of for at least 10 sec then start the car. This allow values to be stored for the throttle adjusting unit. I would be inclined to swap to a good known battery and see if this cures your problem.

POST 5Original post

The procedure you show can be performed at any time but there are other conditions which must be met. This works with all eGas 996's. I think that disconnecting the battery will reset the adaption values regardless of the other conditions,

POST 6Original post

That's interesting Richard the conditions aren't listed in the 986 manual(least not in the battery change bit ). Blomin dificult with a battery change in the snow to get temps over 10deg C .[ ]

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