2003 XJ8 Code P1121

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Oct 7, 2013 | 08:28 PM

juliovega914

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From: Sound Beach, NY

2003 XJ8 Code P1121

So I have an '03 XJ8, and it just threw a P1121 on me. Note its p1121 only (besides the p1111 or p1000 code it threw after I cleared codes.) No 16XX codes like you usually see.

About 7k miles ago I replaced the throttle body with a JayTan rebuilt one, so I am not in a rush to blame the TPS just yet. I checked all the fuses, none blown. Anything you guys can tell me?

Oct 7, 2013 | 10:09 PM

sparkenzap

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From: atlanta ga

Well if it is not the TB, it would seam it is a bad wire or connector. Try looking at the connections for corrosion, then clean well with contact cleaner and reseat.

The JTIS diagnostics say:
Pedal position sensor to ECM sense
circuits 1 and 2 open circuit, short
circuit or high resistance

Sensor power supply fault

Sensor reference ground fault

Pedal position sensor failure
Good Luck

Oct 8, 2013 | 03:45 AM

Sean B

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From: Sunny Southport UK

P1121 isn't the TPS but the TPPS (throttle pedal position sensor) on the other side of the tb - this is more likely worn out if not replaced - if it keeps doing it, gradually getting shorter between restricted performance it'll need replacing.

Oct 8, 2013 | 02:34 PM

flay

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From: Romania

As long as none of the PS are available as spare, probably in these cases is more indicated to recommend a full refurb of the throttle body. I assume that they are changing both during the refurb process... or not? Anybody can guarantee this?

Is the car a X308 or X350?

Last edited by flay; Oct 8, 2013 at 02:40 PM.