Member Since: 03 Nov 2022
Location: Cornwall
Posts: 30
Failed MAP sensor?
I've been having fun with Restricted Performance codes for the past week. Traced it to a cracked intake manifold that I've patched for now and confirmed with a smoke test that it's no longer leaking.
However I've noticed that when looking at live values in my Gap IID I'm not getting read out for some values, such as "Manifold absolute pressure" and "Mass air flow".
I've thought before that my Gap wasn't reading values correctly when I was trying to diagnose start/stop issues, but I'm fairly certain that this time last week when the RP issues started I could at least get MAP and definitely had both MAF readings (because I remember them being wildly different!).
Is the lack of read out from MAP an indication of a failed or damaged sensor, or is this a Gap issue?
Screenshots of values at various RPM (in neutral at a standstill)
28th Aug 2023 11:44 am
PROFSR G
Member Since: 06 Mar 2017
Location: Lost
Posts: 5044
Manifold pressure (actuations) ie boost pressure actuator, and adjustment, are represented in % for both MAP and boost. Manifold (actual) pressure will read in kPa/psi, both MAF sensors will read in g/s (grams per second) though this value is variable between the two depending on engine speed and load.
Make sure you have "pending faults" active on your IID, if there was a sensor faulty there would be a fault logged or "pending". Psi readings are a bit outdated, try changing the tool set up to kPa (Kilopascals) as it's easier to spot an anomaly.yµ (idµ - eAµ) ψ=mψ
29th Aug 2023 12:08 am
jdumont
Member Since: 03 Nov 2022
Location: Cornwall
Posts: 30
Pending faults is already active, and nothing being returned yet. I've also changed my units to kPa, but units aside should I be expecting values for those two rather than "N/A"?
What values in the Gap tool would you recommend to keep an eye on intake values that may have a bearing on restricted performance issues?
29th Aug 2023 8:20 am
PROFSR G
Member Since: 06 Mar 2017
Location: Lost
Posts: 5044
Yes you should have a value for both MAF and MAPS, it may just be a GAP glitch as I've seen this behaviour before.
Monitoring for performance related faults is not really of much use in the absence of any fault codes.yµ (idµ - eAµ) ψ=mψ
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