I own a 2001 Jaguar XKR Convertible, 4.0L supercharged. It
is my fourth Jaguar.

The check engine light is on. I took the car to my local
Jaguar dealer. They diagnosed the fault as P1647 ... upper
oxygen sensor driver's side (US car). The sensor was
replaced.

Dealer thought the problem was fixed. Dealer was wrong.

The fault continues. Frustrated, I took the car to
my local mechanic. He verified the fault as P1647, upper
oxygen sensor driver's side (same diagnosis). He replaced the sensor. The fault continues. The part used each time is LNE1684BB, which
is the OEM part.

Frustrated, I have tried to isolate this check engine light
failure on my own. As a result, I have reproduced the fault,
and recorded an absolutely REPEATABLE set of steps. This
information was sent to Jaguar Coventry, who tossed the
inquiry [or enquiry] back over the pond to Jaguar customer service US.

The steps I validated:

Engine off. Insert Car Diagnostic Scanner Tool. Turn
ignition to ON. Do not start the car.

After verifying protocols, tool reads P1647 fault.

Reset the fault.

Turn ignition OFF. Remove tool.

Drive car. CHECK ENGINE light stays OFF. Doesn't matter if
it is highway, local, 5 minutes, or 2 hours. No check engine
light appears.

Stop engine.

Restart car. Within 10 seconds, check engine light
re-appears. Driving car does not reset light. Again, doesn't
matter what drive pattern is used.

Repeat process with Car Diagnostic Scanner Tool. (Diagnose
fault as P1647, reset fault, remove tool.)

Drive car. Check engine light remains off.

When car is re-started, whether 5 minutes or 2 days later,
check engine light re-appears.

Pattern is 100% repeatable.

Initial use following reset with tool is successful. Next
engine start ALWAYS FAILS.

Replacing upper oxygen sensor with OEM part does not change
the pattern.

Replacements was US$650 cost at dealer, and US$450 with my local
mechanic.

Contacted Jaguar Coventry. They forwarded this letter to
Jaguar North America. I again asked them to please review my
inquiry. The dealer was useless. My local mechanic achieved
the same result.

Jaguar Customer Relationship Center Representative (I will
withhold person's name) said go to authorized Dealer.
Obviously, the representative did not read my information. I
again sent the message.

Received same response with additional: dealers have
technical team to diagnose and support you.

Unfortunately, it was the technical team that already failed the diagnosis
and charged me plenty for their efforts.

This is not a sensor issue.

Anyone out there have experience with resetting P1647 error
code and keeping it reset? The Jaguar dealer and its
technical team is useless. What's worse, all they do is pass
the buck back and forth across the pond.

 

Welcome to the forum holiday,

I've moved your question from General Tech Help to XK8/XKR forum. Members here with the same model will be able to help.

Please follow this link New Member Area - Intro a MUST - Jaguar Forums - Jaguar Enthusiasts Forum to the New Member Area - Intro a MUST forum and post some info about yourself and your vehicle for all members to see. In return you'll get a proper welcome and some useful advice about posting to the forum.

Graham

 

 

I just posted a response to your thread on the Jag-Lovers site a few minutes ago.

Here is my response...................

In reply to a message from RGrisar sent Sat 6 Aug 2016:

The fault is a 'two-trip' fault meaning that the fault has
to occur twice for the DTC to be logged.
If you check the ECM after the first 'trip' you will likely
see the CODE PENDING. The second time you drive the car, the
ECM logs the fault and sets the MIL.

Many DTCs require the fault to occur TWICE before it is
logged in the module and set the MIL to 'ON'.

I would check the pins and harness from the sensor to the ECM.

If the wiring and connectors are OK, then the fault might be
with the ECM ITSELF.

Semiconductors have been known to fail at times.

bop gauff
--
Bob Gauff Owning and Repairing Jaguars Since the Early 70's
Decatur, TX., United States
--Posted using JagFORUM--

 

The old adage is that if you can't fix it with a hammer you have an electrical problem. The dealer and the mechanic have hammered it, with no success. Since your problem is repeatable I think you have an electric problem.
When you plug in the scanner and clear the code you are establishing a low amperage connection in the electrical system. Then you start it up and all is good. The next time you are introducing a HIGH amperage connection in the electrical system and the problem returns.
My first thought was weak battery but I think more that it is a poor connection. I would start with disconnecting the battery and cleaning the terminals. Then I would go to the connection in the engine bay and dismantle and clean it. Next I would also check and clean the HIGH Voltage fuse connections in the spare tire bay.
Now the last point you need to clean is the is the engine to chassis ground. It is a braided wire running from the engine/transmission to the frame. Passenger side I think.
The problem with these cats are they are very sensitive to voltage and throw all different types of false codes. When they don't get the right voltage readings
Once you have tried all that try repeating your findings and let us know.

 

Thank you Vern. I will check and clean each item you mentioned Sunday. The XKR has 160,000 miles (plus) and lower engine is coated with oil. So suggesting that a compromised electrical connection makes a lot of sense.

 

Let me be sure I understand this...you have spent $1100 to replace a $30 part that while aggravating to replace only takes about an hour tops to do.

The first time the Jag dealer did it without fixing the problem and you let them off the hook? Dealer's are to be held accountable, that's why they get away with charging so much. They diagnosed the problem and charged you to fix it, now they are responsible to FIX IT! At the very least refund all charges, Doctors are the only ones that get away with charging and not curing/fixing the diagnosed issue!

 

Hello Bob Gauff (Dallas TX).

Your reply is spot on. I have cleaned/polished all contacts but still have check engine light failure. I would like to add a small bit of info based on your earlier reply. When the fault code P1647 is NOT reset (high current start), the failure delays between 15 and 20 seconds. Does not matter if car is in neutral or driven. Result always identical. This makes me think the problem is related to the sensor's heater. Perhaps there is a delay until the heater cuts out, and the hotter engine kicks in? So, based on my Jaguar Electrical Guide, page 80, I see a line item that says "EM82-4 HO2S, UPSTREAM ‘A’ BANK – VARIABLE CURRENT (microA)" This suggests to me that there is a pin on the ECM that is not receiving or providing a correct current at the correct time. What are your thoughts please. Thank you very much, Bob G.

 

As Bob says, it's a 2-trip code (like many codes). (Jaguar document this in their codes PDF that's on this and other sites.)

It's a heater circuit fault or sensor circuit fault which may not be the sensor - and after the changes probably isn't!

The heater circuit is easily tested. Working sensor heater is about an ohm usually. I hope someone's tested that and also done pinpoint testing (end to end connection testing of wiring etc).

 

Would be worth checking to see if you are getting power sent to the heater and check its fuse/relay.

 

Interesting- I am having the EXACT same issue. I haven't switched the o2 sensor yet though.

Race- what fuse are you talking about?

 

Don't know but assume the power to the O2 heater must come via a fuse or relay.

 

I HAVE a new o2 sensor, just not looking forward to the teardown required to replace...

 

I kept getting the same code for the upper drivers side sensor. I put in a new one, still same issue. Keep in mind I had recently replaced my Octopus hose which is at the rear of the motor where the O2's connect. Turns out one of the few wires on the PLUG the sensor plugged into had a wire pulled out. I just happen to look close at it cause I was so mad at it still throwing code, one wire was pulled out of the plug. In the plug there are a few wires, 3 or 4 I forget, each wire is held in the plug with a tiny *** rubber grommet in each hole of the plug, I pulled that out and pushed it and the wire back into the hole in the plug, checked them all on the plug from the sensor and the plug it went into. All good no more codes.

 

When I first got my car eleven years ago I had O2 sensor problems. Got new sensors and problem returned. Went to local guy and he monitored the O2 voltage and found the voltage to vary up and down as it should for a short time and then it would stop as in should not. Called Houston and got a new couple of sensors. Also got information that said not to over tighten the sensor when installing. Same info came with new sensor. After making first contact when installing sensor tighten only half of a turn more and no more. Did that and they are still working with no codes.

 

To the several
Jaguar Forums members who replied to my post, THANK YOU VERY MUCH. Here is the current status. Replaced sensor. Polished / cleaned every relay and fuse lug. Checked each related wire for continuity. Measured resistance in applicable wires. Still shows check engine light. Fault code remains P1647P along with P1000. Have not tried suggestion by EZDriver (yet) but plan to execute soon (... tighten only half of a turn more and no more). Delay only because of mechanic's expense. Frustrated. Does anyone know of a method to permanently disable the check engine light?

 

What happens when you swap the plugs? Does the fault move? Mine did-so I knew it was a bad O2 sensor. My issue was resolved after replacing.

 

Here is the diagnostic proceedure from the JTIS, While you've verified some measurements I'm not sure what you used for reference. Try this if it all looks correct you may need to send the ECM out for testing, Do a search there is a reputable company that can perform this many here have used.

Under no circumstances must the sensor wiring be cut to facilitate removal, should this prove necessary.Before commencing this test, check the sensor connections and harness, check for exhaust leaks, engine misfire, etc. See 'visual inspection chart' and 'possible causes'.Early production vehicles have wire colour codes that are different from that shown. Use connector pin numbers for wire identification.

CHECK THE H02S VARIABLE CIRCUIT FOR HIGH RESISTANCE
Disconnect the battery negative terminal.Disconnect the H02S electrical connector, EM23.Disconnect the ECM electrical connector, EM82.Measure the resistance between EM23, pin 03 (G) and EM82, pin 05 (G).Is the resistance greater than 5 ohms? REPAIR the high resistance circuit. For additional information, refer to the wiring diagrams. CLEAR the DTC. TEST the system for normal operation.

CHECK THE H02S VARIABLE CIRCUIT FOR SHORT TO HIGH VOLTAGE
Reconnect the battery negative terminal.Turn the ignition switch to the ON position.Measure the voltage between EM82, pin 05 (N) and GROUND.Is the voltage greater than 1 volt? REPAIR the short circuit to high voltage. For additional information, refer to the wiring diagrams. CLEAR the DTC. TEST the system for normal operation.

CHECK THE H02S VARIABLE CIRCUIT FOR SHORT TO GROUND
Turn the ignition switch to the OFF position.Measure the resistance between EM82, pin 05 (N) and GROUND.Is the resistance less than 10,000 ohms? REPAIR the short circuit to GROUND. For additional information, refer to the wiring diagrams. CLEAR the DTC. TEST the system for normal operation.

CHECK THE H02S CONSTANT CIRCUIT FOR HIGH RESISTANCEMeasure the resistance between EM23, pin 04 (G) and EM82, pin 11 (G).Is the resistance greater than 5 ohms? REPAIR the high resistance circuit. For additional information, refer to the wiring diagrams. CLEAR the DTC. TEST the system for normal operation.

CHECK THE H02S CONSTANT CIRCUIT FOR SHORT TO HIGH VOLTAGEMeasure the voltage between EM23, pin 04 (G) and GROUND.Is the voltage greater than 1 volt? REPAIR the short circuit to high voltage. For additional information, refer to the wiring diagrams. CLEAR the DTC. TEST the system for normal operation.

CHECK THE H02S CONSTANT CIRCUIT FOR SHORT TO GROUNDMeasure the resistance between EM23, pin 04 (G) and GROUND.Is the resistance less than 10,000 ohms? REPAIR the short circuit to GROUND. For additional information, refer to the wiring diagrams. CLEAR the DTC. TEST the system for normal operation. INSTALL a new H02S. CLEAR the DTC. TEST the system for normal operation.

If the DTC is repeated, contact Dealer technical support for advice on possible ECM failure.

 

Like ezdriver said, swapping the sensors would show a bad sensor if the fault moved. If your scanner has live data just view that and look at the o2 voltage. The 2 upstream sensors should do about the same thing and so should the 2 down stream sensors.

It looks like your code is for the bank 2 upstream (pre cat). You can just look at the voltage. Compare it to the bank 1 upstream. The numbers do not need to be an exact match but they should behave similarly. The JTIS procedure Jam posted should pinpoint the problem unless it is intermittent, although it sounds like the problem is pretty constant.

 

Finally -- Success. The check engine light is out. I want to share this success story with the many wonderful Jaguar Forum people who helped.

I bought the 2001 Jaguar XKR two years ago. Basically a great car with a handful of inherited issues. One by one these were resolved, except the check engine light.

The car said P1647, which is the upper (Lambda) Oxygen Sensor on the left (US driver's) side. OK. I checked the dealer price for the repair. Almost $1000.00. That seemed a bit much for a 16 year old car that cost $6500.

So, naturally, I tried to go cheap. Found a replacement O2 Sensor on eBay. I think it was $50 for two. Made an arrangement with my local garage mechanic. Yes, he said he would do the work. He estimated about 3 hours since he had not done anything like this before, and he primarily works on American muscle cars. OK. Let's do it.

He decided to go to the location from the top, instead of dropping the exhaust. He said that he would need addition parts (exhaust seal for example) and who knows if these were available locally. He removed and replaced the existing O2 Sensor and installed the new (cheap) one. He had to cut the connector off the original part and splice the wires to reuse the connector. After installation, I still had the O2 sensor failure.

He said that I needed to get an original Jaguar part. That these aftermarket parts and worthless. He said that if I provided the OEM part, he would do the reinstall at his cost. I don't know about your experience, but I bet the Jaguar dealer would not make an offer like this.

So I contacted my long-term supplier on the West Coast who helped me for years with my XKE. If you have or have had an XKE you probably know them. They quoted about $200 for an aftermarket part and $350 for a genuine OEM part. I hesitated. I told them I needed to shop around.

Called some of the obvious Jaguar parts suppliers. The winner was SNG BARRATT. The quoted about $210 for the OEM part including shipping. Ordered the OEM part from them. Delivery was delayed by UPS due to the tropical rain storm that passed through North Carolina, but patience prevailed, and the part arrived.

With the part now firmly in hand, scheduled the repair with my regular mechanic. Then the day came. He opened up the engine and found the hardness side has a male connector, and the supplied part has a male connector. Unbelievable. To cut through the story quickly, SNG BARRATT has a printing error in their catalog on page 103.

After calling multiple times and explaining the error in the catalog that caused them to send me the wrong part, we determined the correct part for my car. This time with a female connector. And the price including shipping was $160. They agreed to issue a credit for the wrong part once it was returned.

A week later the part arrived. Went to the mechanic and he again scheduled the repair. We verified that this time the part had the correct female connector.

The day came. The repair was performed. I went to pick up the car, and he said the repair was not complete. In removing and replacing the water overflow tank, he broke one of the plastic tubes. He was reattaching it with some kind of thermo-glue and it needed overnight to set. Then he would test the car to verify the repair.

OK. The next day I stopped bye mid day to see if the car was repaired. He said the check engine light remained lit. He tried everything. Disconnecting and reconnecting the battery, using his high-end auto scanner to reset all codes, starting and stopping the car on an extended road trip -- everything. He said he was sorry, but I needed to take the car to the Jaguar dealer who has more sophisticated tools for dealing with Jaguars. He had done all he could do. There was no additional charge beyond those of the first day. He basically did the repair three times, plus all the diagnostic work.

Later that same day my wife and I drove over to pickup up the car. Low and behold the check engine light was out. I couldn't believe it. I started and stopped the engine twice to make sure. I was convinced something was up.

I went back into the office and asked "how did you do it?" Puzzled, they said the check engine light was on and they didn't know what else to do. I explained that the check engine light is off, and asked if they removed the dashboard bulb or something. No, they had not. The car was repaired and no one knows exactly why.

OK. We all have been led to believe that the P failure codes have to happen twice before they are set. We also know they have to not happen twice for the car's computer to reset the code. Well, maybe that is not true. The garage mechanic started the car four times. On the fifth try, I started the car and it worked. I have driven it many days since, with no evidence of any check engine light or any other failure.

Like most folks, I post my problems in the forum to get possible answers from the wealth of experience of others. This time, I am posting a success.

Thank you to the many folks who have helped. One specific was not to over tighten the sensor. Just snug, then back off a half-turn. Another was never buy cheap crap on eBay. Deal with real suppliers that offer genuine Jaguar parts. Last, everyone needs a garage mechanic like mine. I have been doing business with him for many years. No problem is too difficult. He always treats me (and all his other customers) fairly and honestly.

So thank you again for reading my story. If you need more specifics, just reply.

A firm supported of Jaguar Forums!!!