ECM from my 2006 XJR with 171XXX miles on it

I am looking for a used DENSO ECM for my 2006 XJR. My question is whether the ECM for the supercharged XKR, Supercharged S type and XJR are interchangeable, and for which model years. These cars are all 4.2 liter but some of the replies to one of my other threads gave the impression that the connectors for the 2003 - 2005 XJR are different than on my 2006. I have sent a parts inquiry to Jaguar Heaven in California and will also talk to Mathews Foreign Car Parts in Birmingham, Alabama and wanted to find out if I could enlarge the pool of choices.

I saw one listed on eBay as a Denso MB079700- 9074 which is different from my Denso MB279700-9221. The one on eBay does not state what model year XJR it is from.

 

Why are you looking to swap out your ECM?

 

In my thread about multiple codes and not being able to start the car, I mentioned that I sent the ECM to G7 computers in NY for diagnostic and repair. They did find a bad resistor in one of the circuits to one of the microchips for the ECM, replaced the resister and sent the ECM back to me. I installed it and had all of the codes all over again, none of which will clear. I can send them back the ECM for further diagnostics or have offered to provide a refund.

So, I am looking to replace the ECM in an effort to resolve the problem.

 

Since there were major electronic differences between the pre 2006 MY XJR and 2006 MY XJR onwards I would not be surprised if
electrical connectors were different.

The respective ECUs are definitely different. The 2005 will not see VVT whereas the 2006 will as just one example.

 

To add here you want to find the same type of ECM. Regardless it will need to be re flashed by legit Jaguar software (SDD or IDS) and a legit reader like Rotunda VCM.

I would find one from an XJR, not STR or XKR models to hopefully have a chance of success.

I'm guessing the bad resistor wasn't the root cause of your problem. Take a step back and look for a common denominator that could be tied to the codes.

 

G7 Computers said that they would take another look at the ECM and diagnose to see if there is something else wrong with it as part of the original diagnosis and repair fee. They should receive it by Tuesday.

Abonano;

Your comments about flashing bring up an interesting question. Assuming G7 does not find anything additional wrong with the original ECM, and even if they make a further repair, would that have caused a loss of the original data from the original flashing? Does the flashing of the ECM have to be done in the car, or can the ECM be brought to the dealership to be re-flashed and then reinstalled?

Even with the ECM removed, with the battery connected, door locks still work, as do lights and trunk release and the car is maintaining ride height.

With 9 different error messages:

Gearbox Fault, Low Brake Fluid, DSC Not Available, Cruise not Available, CATS System Fault, Air Suspension Fault, ABS Fault, Cannot Apply Parking Brake, Tyre Pressure System Fault, where else should I look?

Codes read were P0504, U0103, U0104, P0232, U0415, P0056, U0121, P0036, U0101 and P0031

P0232 "Rear Electronic Module - Fuel Pump drive circuit fault *DTC flagged by REM in REM caused by ECM to ignition coil primary circuit fault". Where is the Rear Electronic Module located?

U0103 "Lost communication with gear shift control module"

P0031 "HO2S Sensor heater control low current"

P0036 "HO2S Heater Control Circuit Bank 1 Sensor 2"

P0056 "HO2S Heater Control Circuit Bank 2 Sensor 2"

In addition, codes were read by iCarSoft i930: U2521 "Adaptive Speed Control CAN DSCM Missing" , U2522 "Adaptive speed control - CAN TCM Missing", U2510 "Security (PATS) - CAN invalid ECM Data for Vehicle Security incorrect PATS identification - IC/to ECM", U2515 "Dynamic Stability Control - CAN Adaptive Speed Control Message Missing" and Instrumentation - CAN ASCM Data Missing, U2522 "Adaptive Speed Control - CAN Adaptive , Dynamic speed control - CAN TCM Missing, Instrumentation - CAN TCM Gear Selection data missing".

I am still trying to find descriptions for the other codes.

 

Were all of those cleared and then quickly came back? Seems unlikely.

Some look to be transient/power-related.

If the HO2S ones keep flagging then as they're vital devices find & fix what's wrong.

Generally the PCM is very robust and not to blame...

 

Well, all of this started overnight. I drove the car the day before and all these error messages and codes were present when I got in the car the next morning.

Battery (an Exide I had bought 2 1/2 years ago) was indicating less than 12 volts. I replaced that battery with a Bosch indicating 12.80. There was a resister in the ECM that was found to be defective when the ECM was tested. So, in this case, the ECM had a problem. If I understand correctly, each system that had an error message communicates with the ECM? Since I can't start the car, I can't check for

G7 Computers graciously agreed to take a second look at the ECM to see if there might be something else that failed.

So, I am assuming the data flashing puts in the ECM is installed in the "chip"? The question becomes whether the memory is still saved in the chip.

I am open to any suggestions about where else to look at this point.

I am assuming that next on the list will be to reflash the ECM, hence the questions about doing so.

 

You may have had false codes due to the battery.

So long as they've repaired the PCM without adding faults then a dealer tool can reflash, though the repair should not have lost the module's programming.