XJ8 - giving it some much needed mechanical TLC since purchase as 3rd owner. Using OBDC reader two codes keep appearing P1000 and P0112. I have changed the air filter and MAFS, cleaned the connection with electric cleaner as mentioned in the forums. Any feedback would be appreciated.

 

You probably already know these, but here it is anyways....


P1000 ..OBD Systems Readiness Test Not Complete
- Be sure the connection is complete on the plug and don't disconnect it without completely rotating the key back to the off position.
P0112 - Intake Air Temperature Circuit Low Input
- Faulty Intake Air Temperature (IAT) sensor
- Dirty air filter
- Intake Air Temperature (IAT) sensor harness is open or shorted
- Intake Air Temperature (IAT) sensor circuit poor electrical connection
- Check for cracked wires and/or broken connectors


With you being in Louisiana, its similar to me here in FL, the humidity is our enemy. So any faults in the wiring is accelerated from that. Things such as corrosion on the positive battery terminal wire. It allows it to eat down into the shielding and it doesn't clean off, you have to replace it.

 

We have a new air filter and a new mass air flow sensor. Is the IATS the same as the mass air flow sensor?

 

IATS = Inlet Air Temperature Sensor.

 

But it is integral to the MAF!

 

I cleaned the butterfly flap inside the MAFS. Reached deep down using throttle body cleaner on a lint free rag. All clean and shiny. Checked all the electrical connections around that area. Clear the PBS 12 error and did a test drive about 6 miles. OBDC was connected through Torque on my phone. No errors. Going for a longer drive later today and will watch for check engine light then check any codes.

 

P1000 isn't anything to worry about. Disconnecting the battery cables and touching them together resets the computer and solves minor glitches. MAF and throttle body cleaner are different products. I use the stuff from CRC.

 

Yes, they're both contained in the same unit....

 

Check engine light came on during last night's drive. Ran Torque this morning and it registered P0111 and P0112. Web lookup shows generic Bank 1 Intake Air Sensor low circuit errors. Continuing to look for the cause.

 

I agree with High Horse about corrosion on electrical connections. There are three sets of ground connections to look at. One set behind the headlights on each side secured with a dome nut. Get some electrical contact cleaner and remove the domed nut and clean each wire lug and the surface of the nut with steel wool and the contact cleaner. I coated each of mine with bulb grease before reconnecting. The third set is mounted on a similar stud at firewall in vicinity of the throttle body.


See if the codes go away after cleaning the ground connections.

 

You are looking for a problem with the orange wire to the ecu or the black/green wire to ground in the MAF connector.

JTIS says the orange wire should read .98 volts to ground at 10 degrees C, decreasing voltage with temperature increase. The code is for "voltage too high" which would mean the wire to the sensor or the one from the sensor to ground is probably open, since the sensor pulls current to ground.

It probably would be helpful to set your Torque to read the IATS parameter and see what you have happening.

Have a look at the JTIS troubleshooting procedure:

 

With a lot of expertise on codes, I would like to ask about C1095, "pump motors circuit failure," with an ABS light

I get this from time to time, clear it, and it does not come back. Sometimes it clears itself from one start up to the next.

Does this mean I probably have such a failure or not, if it clears itself?

While there is a fair amount of discussion about it on the site, what is this likely to be and what can I tell my mechanic to try to look for? I figure troubling shooting something electrical is beyond me.

Thanks

 

My XJ6 had the same symptoms. Finally the light came on every time I started moving and it was time to resolder the pump connections in the abs module. Here is a procedure for repairing the module without opening the case:

JagRepair.com - Jaguar Repair Information Resource

 

Yeah, RJ has it spot on. The pump connector is a well known problem, on both the X-300 and the x-308. I am 4 for 4 on these damned connectors on my X-300 / X-308 cars!

 

This procedure is nuts on, I just did this to mine about 6 months ago and haven't had an abs or restricted performance light on since. I never got the codes you have though.
Instead of using the cover for the hole mentioned, I went to the local hardware store (Lowes in this case) and picked up a .15 cent cover plug (from their specialty parts drawer in hardware) the same size as the hole saw I used (3/4" I believe). I used a small bead of silicone under the lip of the plug to seal it, snapped it in and it looked like it belonged there.

 

I'm still searching for the source of my P0112 fault code. Cleaned the MAF sensor w/MAF cleaner and the electrical connection w/ electrical cleaner. The code persist. Switched to the previous MAF. After cleaning it thoroughly the P0112 has gone only to be replaced by P0171 and P0174.

Any suggestions?

 

Try this...
http://repairpal.com/OBD-II-Code-P0171-and-P0174
....I've done the O2 misdiagnose on my truck.

 

When you gently pull the wiring harness off the MAF sensor, check the wires for breakage (go back and re-read ZAP's instruction on which wires), using contact cleaner, clean both male and female plugs, let dry and reinstall seating cleanly and try again. In the end, you may need a new MAF . . .

 

Been driving most of the week and monitoring the OBDC. P0174 and P0171 have been appearing after each clearing of the fault codes. Today removed all the 'pipes' from the air box to the throttle body. All the electrical connections are cleaned as well as the inside of all the 'pipes'. Removed the MAS and replaced with the new MAS that was causing the the other two fault codes. Will drive the XJ8 to day and see what fault codes may appear. I will replace this MAF if something appears in the TORQUE application. More to come ...

 

My GUESS is that each MAF sensor has a different problem!