11 captured repliesDiscussion pagination complete · Source accounts, not a confirmed diagnosis
THIS DISCUSSION / SOURCE-DERIVED OVERVIEW
Discussion summary
YOUR RESEARCHwarning lights at 5000 rpm
Reported or suspected cause
mass air flow sensor
Reported cause
No successful repair reported for this finding.
1
Identified cause
0
Suspected cause
0
Reported fixes
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 report identifying a cause
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.
Reported cause · Original poster
Little trip down to Northway today and it was the MAF sensor.
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
Broken switch = no PSM or ABS, hence the lights.Iif you're not getting any performance degradation or other issues it's certainly worth checking - the easiest way is simply to see if your brake lights are working properly when the ABS/PSM lights come on.
Leading evidence: 'mass air flow sensor' (1 discussions report identifying this cause; no attributable repair resolution). Across 1 matching discussions, the most frequently mentioned possible cause is 'mass air flow sensor' (1 discussions; 1 report identifying it and 0 suggest it). The most frequently discussed action is 'Check the easiest way is simply' (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 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
Very grateful for your advice..cleaned sensor with carb cleaner..put it back together and problem appears to be solved...took about 30 mins and saved about £250...here's hoping its a permanent solution.
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
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
Fitted new MAF..running fine.no warning lights after 5000rpm..thanks
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
Broken switch = no PSM or ABS, hence the lights.Iif you're not getting any performance degradation or other issues it's certainly worth checking - the easiest way is simply to see if your brake lights are working properly when the ABS/PSM lights come on.
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.
These are separate views of the same evidence. Frequency alone does not establish a fix, and these counts must not be added together.
Check the easiest way is simply
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
Broken switch = no PSM or ABS, hence the lights.Iif you're not getting any performance degradation or other issues it's certainly worth checking - the easiest way is simply to see if your brake lights are working properly when the ABS/PSM lights come on.
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
Very grateful for your advice..cleaned sensor with carb cleaner..put it back together and problem appears to be solved...took about 30 mins and saved about £250...here's hoping its a permanent solution.
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.
11 eligible posts · 0 unverified posts · 1 discussions match the subject in their title or opening post.
911uk: 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: 20261026T133652Z · outcome-qualification-6. Deterministic extraction; no AI model inference. How we use sources
996 C4 when getting upto 5000 rpm the PSM and ABS orange dash lights come on.
Turn ignition off and re-start and they are off again.
any thoughts
thanks Richard
Migration info. Legacy thread was 67822
Thanks for reply,
is this a simple job as I was thinking abut service anyway and will ask them to check this out
thanks
Richard
Migration info. Legacy thread was 67890
I don't know what year your car is, but there was an issue on pre-facelift 996s that caused the PSM and ABS light to come on and had nothing whatsoever to do with the MAF or any other engine related sensors. This involved an intermittent contact inside the brake pedal switch - the one that sits just above the brake pedal inside the car and switches on the brake lights when you press the pedal. On my old ('99) C4, these things used to fail with monotonous regularity. I even kept a spare in the door pocket! They only cost about £12 (IIRC) to buy and take about 3 minutes to fit as a DIY. The reason this caused the PSM and ABS lights to come on is that both systems rely on this switch to sense whether the car is under braking or not. Broken switch = no PSM or ABS, hence the lights.Iif you're not getting any performance degradation or other issues it's certainly worth checking - the easiest way is simply to see if your brake lights are working properly when the ABS/PSM lights come on.
Ian W
Migration info. Legacy thread was 68829
no it will be the maf sensor if you are revving the car at 5,000 rpm and the lights come on as the signal from the dme is cut thus turning off the the psm system .if there is a problem with the brake lamp switch it will not put any lights on whilst you are accelerating .when the maf sensor is faulty will enter two faults one in the psm system and one in the dme fault memory
Migration info. Legacy thread was 68887
Hi ...had same problem on my 996 C4 tip. Very grateful for your advice..cleaned sensor with carb cleaner..put it back together and problem appears to be solved...took about 30 mins and saved about £250...here's hoping its a permanent solution.
Migration info. Legacy thread was 72528
