Hello all,

I have been experiencing restricted performance with my car, when in rp mode, I lose the coolant gauge reading, needle drops to bottom. Fluid level is fine, and good to -40F. The CEL finally came on, so I went to AZ and the codes were

0117 Low coolant temp (irrelevant)
0196 Low oil temp (I'm assuming also irrelevant)
1111 reporting a problem with air mixture metering

So, I know I need to clean the maf, but I cannot find the faq here on the site. Also, any reason why rp would cause me to lose the coolant temp gauge? Finally, I also want to clean the TPS sensor connection, but I cannot figure out how to unplug the connector and I don't want to break anything.

All advice or tips are greatly appreciated.

 

Why are you assuming low coolant and oil temps are irrelevant? They most likely are the issue - the codes imply intermittently failing or disconnecting or outside of norm signals from the sensors to the ECM causing it to throws codes and force RP. I'd look for a bad/loose/dirty connection that is shared between both.

The BLACK/GREEN stripe wire supplies power to both sensors so I would suggest you look there first - if it's got an intermittent connection somewhere downstream, this would cause your codes.

P1111 is normal - OBD system pass... where are you getting your code definitions from? Not the Jag reference, obviously.

 

I think he means the actual temp of the oil and coolant is irrelevant and that it is obviously an electrical problem.

 

I think I meant something between the two... I was assuming my rp was caused by the maf, and therefore the low temp readings were irrelevant. However, I never considered that it could be electrical, makes much more sense Quadmaniac. I know from other posts that 1111 is pass for the OBD. I had the codes read at AutoZone, and when the p1111 was displayed, it also showed "air mixture metering." Because I went in assuming it was an maf issue, I took that as a confirmation of the maf problem. I'm still learning my way around under the hood of my new cat, so can you please tell me where to find the black/green strip wire and where the ECM is? Thanks so much.

 

I suspect the fault is in a joint or connection where the black/green wire splits off to go to both sensors. The wiring diagram, available here: http://www.captainjaguarscathouse.co...ec%20Guide.pdf , shows a connection called PI1-6 (connector PI1, pin 6).

Connector PI1 appears to be at the rear of the engine, near the firewall, mid right hand side (from the wiring diagram:
PI1 57-WAY SUMITOMO TS090 / BLACK ENGINE COMPARTMENT / BULKHEAD / REAR OF ENGINE).

There is also a junction that feeds these two sensors (ECTS and EOTS) called PIS1 (a junction that has 1 Black/green wire in and 4 out, probably somewhere near the PI1 connector). I would look for a fault in either the PI1 connector or at the PIS1 junction - likely wires soldered together with shrink tube covering the joint. Look for the connector (PI1), find the green/black wire at pin 6, and follow it to the junction, and from there to each sensor. It's very likley you'll find a corroded connector pin or a loose joint at the junction.

If it was just ONE of the sensors causing CEL codes, I'd predict it was at the sensor's connector... but since it is both sensors, and it's not likely that both connectors have corroded/failed at the same time, AND since they share the same supply input, the above is my best guess as to where to start looking.

BTW, I assume you have the AJ27 engine as the AJ26 does not have the EOTS (oil temp sensor). It appears as if the switch between 26 and 27 was made mid 99 MY.

 

When I was doing some research on my one RP event - I discovered that the instrument cluster has outputs to the engine and or body computers.

So a failed output from the coolant temperature gauge will give you a RP -- this signal first goes to the climate control. The same may be true for the oil.

Its ridicules that the car should go into RP for this fault. The dealer told me this was a prime reason for the instrument cluster to be replaced under warranty.

I have never had it happen again.


Be very careful cleaning the MAF -- I would leave it alone unless you are sure it is causing a fault. We have never been able to save a failed MAF with cleaning.

 

2000 jaguar xj8 vdp wont start had a resticted performance and engine stalled pulled codes p1111 p1367 p1368 p1000 and po351 thru po358