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A broken cable will trigger the fault message. I have spare cables if you have a need. I need another set of eyes to watch my calipers operate just to be certain that they are functioning via SDD and they it’s not just the actuator I hear.
A broken cable will trigger the fault message. I have spare cables if you have a need. I need another set of eyes to watch my calipers operate just to be certain that they are functioning via SDD and they it’s not just the actuator I hear.
If you remove the disks you can just manually actuate the calipers. That's how I ruled out my calipers being faulty.
Anyway I replaced the pads but still the warning persists. I have one more trick up my sleeves... turn the caliper piston all the way in and see if that does anything.
I did find some useful information on another forum, someone cut a hole out in the trunk and replaced the actuator from the top. I'll look into this if it comes down to replacing the actuator.
After playing with it more in SDD I can confirm the actuator and calipers are indeed working but ONLY when using SDD. As soon as I close the session, the error returns and none of it is functional. And now the error message has gone from amber to red when underway and back to amber when stopped.
Any thoughts about what might happen if I remove the module completely? I guess since it is tied to the ECU the error will
persist. Removing the fuse did nothing as well. It’s odd there are no DTCs and that it works fine manually
in SDD. It’s also weird that it happened after battery voltage dropped while sitting at a shop.
Any thoughts about what might happen if I remove the module completely? I guess since it is tied to the ECU the error will
persist. Removing the fuse did nothing as well. It’s odd there are no DTCs and that it works fine manually
in SDD. It’s also weird that it happened after battery voltage dropped while sitting at a shop.
I did read somewhere in that PDF link I posted that indicated a voltage drop could cause the problem but it didn't say anything specific.
What is the warning message you're seeing that went from amber to red Jeremy?
Amber is PARK BRAKE FAULT and red, when driving only, is CANNOT APPLY PARK BRAKE. I did not have the later message when driving back from collecting the car from the shop, it only came about after using SDD. No DTCs, no CAN faults. I have not done any other pinpoints or diagnostics other than visual.
Amber is PARK BRAKE FAULT and red, when driving only, is CANNOT APPLY PARK BRAKE. I did not have the later message when driving back from collecting the car from the shop, it only came about after using SDD. No DTCs, no CAN faults. I have not done any other pinpoints or diagnostics other than visual.
Thanks. Those messages are both technically CAN but I assume you mean no CAN related DTC's as you'd expect, so no direction. I'd still move to checking the can bus resistance and voltages at the actuator and/ or module per the PDF, even though you don't seem to meet the CAN Bus integrity gaps:
I'd do it simply because it would drive me bonkers.CAN Diagnostics
Advanced Diagnostics
Checking the Integrity of the CAN Bus
The integrity of the CAN bus should be checked if:
DTC analysis indicates that one or more control modules is missing from the CAN bus.
DTC analysis indicates ‘CAN bus off’ faults.
It is not possible to establish diagnostic communica- tion with any of the control modules on the vehicle (but it has been proven that the diagnostic tool is not faulty).
The following procedure should be used to check the integrity of the CAN bus:
If DTC analysis has identified a ‘suspect control module’, the diagnostic routine should start with this control module.
With the ignition ‘OFF’, unplug a control module from the CAN bus.
Some ABS/DSC modules are connected to the vehi- cle CAN bus and to a separate ‘private CAN bus’ that goes only to the vehicle’s Yaw/lateral accelera- tion sensor. Check the circuit diagram to ensure you have correctly identified the vehicle CAN bus.
Identify the CAN pins in the unplugged control mod- ule connector. The unplugged control module con- nector will have either two or four CAN bus pins (depending on how it is linked into the CAN bus). If there are four pins they will be grouped as two pairs. CAN pins into a control module connector are always grouped as pairs, known as CAN high (+) and CAN low (–). Each pair of CAN pins can nor- mally be identified by the wires to them being twisted together.
Measure the resistance across each pair of CAN pins. The resistance value should be either 60 (± 5) or 120 (± 5). Whether the value is 60 or 120 depends on where the control module is located in the CAN bus relative to other control modules but for this test it does not matter which value is recorded as long as it is one or the other.
6. With the connector still unplugged, but this time with ignition switched ‘ON’, measure the voltage between CAN high (+) and ground. The reading should be 2.7V. Now measure the voltage between CAN low (–) and ground; the reading should be 2.3V.
7. Switch the ignition ‘OFF’ and re-connect the con- nector to its control module. Select another control module on the CAN bus and repeat tests 4 and 5.
If, in the 7-step procedure above, no unexpected read- ings are taken, the integrity of the CAN bus is good.
It should be noted, however, that intermittent faults can exist. If the nature of the fault is intermittent, the cable harnesses should be ‘wiggled’ where possible while car- rying out these tests. Also, connectors to all control mod- ules on the CAN bus should be disconnected and re- connected as this is often enough to clean up light corro- sion which can cause intermittent connectivity.
If, in the 7-step procedure above, an unexpected reading is recorded, it will be necessary to test each section of the CAN bus to identify the fault location. Do this in the fol- lowing way:
In order to isolate a faulty control module, carry out tests 3, 4 and 5 from each control module on the CAN bus.
In order to isolate a wiring fault it may be necessary to check the integrity of the CAN bus wiring between con- trol module connectors, checking for open circuits and/ or shorts to power or ground.
NOTE: If no definite cause was found for a CAN issue after following the procedures, but all DTCs have been cleared and have not returned after a test drive of at least10 miles, the vehicle can be returned to the customer.
You can find the CAN part of the module on Fig 21.1 (for me, page 120 of the PDF).
It shows the wire colours and that HS CAN is used (which the Fig above shows also).
An electrical (computer, in this case) "bus" harks back to bus bars, and here means a transport connecting multiple things (modules). CAN is Controller Area Network, worth a read on the web.
USA (and other countries) mandate the use of CAN by law after a certain date at the latest so Jaguar moved to it. Other car makers, too, it being law.
Decided to have a go at it without SDD, disconnected battery ground for a time, reconnected and started car. Prompted with the usual apply foot brake and park brake, this time with the door open so I could listen. The red brake light on the cluster came on and I heard a series of rapid clicks like a starter motor on a weak battery and was prompted by the usual park brake error message. I then tried pressing down to release the brake and the red brake light extinguished and heard the same series of clicks. Repeating the park brake apply and release no longer illuminated the brake light and of course the noise did not come back. Using SDD to activate the brakes is completely different as I can hear the motor from the actuator operating and the calipers opening and closing. I can do this multiple times without errors in SDD. I also tried a scan tool and only found a cruise control DTC which I was able to clear.
Pardon my ignorance but where did it say press and release 10 times?
sorry, that was the XJ TSB attached earlier above:
If there are any faults with the calipers or cables, these must be rectified before proceeding any further. After rectifying these faults, reassemble the parking brake system ready for use and proceed to next step.
Clear all DTCs.
If the parking brake is not already in ‘Calibration Mode’, carry out a battery disconnect/ reconnect (see Global Technical Reference GTR Workshop Manual, section: 414-01) to put it into ‘Calibration Mode’. When in ‘Calibration Mode’ the instrument pack will display the message ‘Apply Parkbrake’.
The parking brake must now be calibrated. To do this, start the engine, and lightly apply the foot brake. With the foot brake lightly applied, use the drivers EPB switch to apply the parking brake. The parking brake should now be calibrated and should no longer be in ‘Calibration Mode’.
Carry out ten parking brake applies and releases(using the apply/release switch). Wait for the EPB to complete its operation after each switch input. Wait for five seconds in between each apply or release.
Decided to have a go at it without SDD, disconnected battery ground for a time, reconnected and started car. Prompted with the usual apply foot brake and park brake, this time with the door open so I could listen. The red brake light on the cluster came on and I heard a series of rapid clicks like a starter motor on a weak battery and was prompted by the usual park brake error message. I then tried pressing down to release the brake and the red brake light extinguished and heard the same series of clicks. Repeating the park brake apply and release no longer illuminated the brake light and of course the noise did not come back. Using SDD to activate the brakes is completely different as I can hear the motor from the actuator operating and the calipers opening and closing. I can do this multiple times without errors in SDD. I also tried a scan tool and only found a cruise control DTC which I was able to clear.
06-02-2020, 01:22 PM
