I've noticed a few other post that vaguely talk about CLV and STFT/LTFT and I'm wondering if someone could shed just a little bit of light for me. I have a 2000 S Type 3.0 and my Calculated Load Value is 62% and my LTFT for both banks are around -25%. I've seen conflicting info about what's good or not good when it comes to both so I'm a little confused. Oh I do have 1 code on the MIL and its a P1388 (even after dealer reflash). Can someone enlighten me on what the numbers should be in an acceptable range? Thanks

 

I don't normally look at CLV but in any case ignore it until those trims are near 0 (say within +/- 5%).

At what rpm do you see -25%? It means the PCM is seeing the exhaust as so rich that it's subtracting the largest amount of fuel it's willing to do. I don't understand why you don't have rich codes (almost everyone else sees lean codes LOL).

The good news is you probably don't have an air leak.

Ideally you'd get engine hot (warmed up), watch both banks are CL (closed loop) and then look at the trims at idle and about 2500rpm.

If they stay that kind of number, check O2 sensor signals (for your car, voltages) are sane. For HO2S to work they have to be hot (that's HOT) so you may need to drive then park and measure or rev for a minute and measure. The upstream ones should constantly swing from about 0.2V to about 0.8V. The downstream should not swing much if at all.

You need to check the O2s because if they're not working right then the whole engine is out of proper control and you may as well ignore all values (except for diagnosing what's wrong).

If O2s are OK, your MAF may well be reporting the wrong readings but see what others say unless you have access to another free or cheaply.

P1388 is covered elsewhere but reflashing will only fix it if it's being falsely flagged. Sounds like yours is being flagged (non-falsely). The codes PDF (see FAQs, JTIS or Gus's site) will have details I expect.

edit: you can't read many data values per second so only log the O2s (maybe rpm as well) or you won't get a feel for what the volts are doing

 

Here's my latest readout:

2000 Jaguar S-type Engine v6 3.0
Mileage
145000

Stored DTCs

DTC Description
P1388 Variable camshaft timing over retarded, bank 2

Pending DTCs

DTC Description
No DTCs present on code reader



MIL Status
MIL ON

Comprehensive Component Monitor
CCM Complete

Misfire Monitor
MIS Complete

Fuel System Monitor
FUE Complete

Oxygen Sensor Monitor
O2S Complete

Oxygen Sensor Heater Monitor
HTR Complete

Catalyst Monitor
CAT Not Complete

Heated Catalyst Monitor
HCA Not Supported

EGR System Monitor
EGR Complete

EVAP System Monitor
EVA Not Complete

Secondary Air System Monitor
AIR Not Supported

Air Conditioning (A/C) Refrigerant Monitor
ACR Not Supported


Freeze Frame

Parameter Description Value DTC for which Freeze Frame was Stored
P1388

Fuel System 1 Status
Closed Loop

Fuel System 2 Status
Not Supported

Calculated LOAD Value
62.75 %

Engine Coolant Temp
203.00 °F

Short Term Fuel Trim -Bank 1
10.94 %

Long Term Fuel Trim -Bank 1
-25.00 %

Short Term Fuel Trim -Bank 2
4.69 %

Long Term Fuel Trim -Bank 2
-26.56 %

Fuel Rail Pressure
39.57 psi

Engine RPM
2327 rpm

Vehicle Speed Sensor
14.91 mph


Report#
Date: 7-15-2011

 

You don't have P1111 so I suppose you've cleared the codes.
Something's stopping the Cat Monitor.

Back to looking at HO2S voltages.......

 

I never had P1111 show up but I have had P0133 P0153 recently. Sometimes they will show up for awhile and disappear. I have no idea what circuit slow response means though. I guess I'll try looking at the voltages this weekend

 

Read the codes PDF as I said above. Lots of details in it.

Also check those voltages, preferably as waveforms (graphs) so you can really see them.

This is starting to look like awkward DIY as you're going to be trying to figure if the O2s are OK or not, if the wiring is OK or not, if the .... well, you get the idea. Don't skimp on the reading if you're going to DIY.