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Hi everyone Hopefully someone can help with this stupid question
trying to sort out a engine control module no communication problem on a 2003 str
Canbus is fine 62 ohms
have no power at fuse 18 engine compartment
On relay #4 5 pin square type
I have read to test pins 1 3
jump pin 5
can someone please tell me what they mean
would anyone have a diagram of how it's labeled
Thanking you
Last edited by Darrol2004; Nov 21, 2025 at 11:10 PM.
I have read to test pins 1 3
jump pin 5
can someone please tell me what they mean
would anyone have a diagram of how it's labeled
Can you please stand outside in a clearing, away from any power lines or government mind control ray generators? I'm trying like crazy to read your mind but am having no luck.
Which relay is this? Is it a smaller rectangular one? Or a larger square version?
I've noticed the relay sockets (in the fuse panel) typically are NOT labeled. However, the relay body is usually labeled next to the prongs. You have to cross reference them.
Can you please stand outside in a clearing, away from any power lines or government mind control ray generators? I'm trying like crazy to read your mind but am having no luck.
Which relay is this? Is it a smaller rectangular one? Or a larger square version?
I've noticed the relay sockets (in the fuse panel) typically are NOT labeled. However, the relay body is usually labeled next to the prongs. You have to cross reference them.
Hi Karl
Relay #4 is a 5 pin square one
I had tried to cross ref on net but it keeps sending me to dam you tube
Cheers
Darrol
Can you please stand outside in a clearing, away from any power lines or government mind control ray generators? I'm trying like crazy to read your mind but am having no luck.
Which relay is this? Is it a smaller rectangular one? Or a larger square version?
I've noticed the relay sockets (in the fuse panel) typically are NOT labeled. However, the relay body is usually labeled next to the prongs. You have to cross reference them.
Hi Karl
Thats why I'm standing under power lines or government mind control ray generators
You wouldn't want to read my mind at the moment
This car of mine is doing my head in
Especially when you think you might be on to something
But end up back at square one
Cheers
Darrol
I think this is the relay you're after. Pins 1-2 should pull the relay closed across 3-5, it's normally closed across 3-4. You can measure resistance on the coil, somewhere in 60-100 Ohm is good. Across 3-5 should be open, 3-4 should be very close to nothing, <1 Ohm. If you supply 12v power/ground across 1-2, you should feel it engage and your values for 3/4 and 3/5 should invert.
Or, look for another relay of the same design in the fuse box and swap it to test.
Last edited by RoverJoe; Nov 21, 2025 at 09:26 PM.
Also, if you're comfortable doing so without destroying it, you can pop the cover off the relay, and then test the whole circuit on the associated parts of the relay when they are exposed, with it plugged in. This will verify that your control side gets power/ground, and you can also manually close the relay and verify you get power, to determine what side of the circuit you need to go after next.
I found some details for you on the socket numbering. Jaguar uses "ISO relay pin numbers", which is 1 through 5. Lots of other relays use a Bosch standard from who knows when, with truly oddball numbers (30, 85, etc.). The relays are pretty much the same internally, but the labels are different. Very confusing. Most online sources only show the confusing Bosch system.
I did find a Wells 1R3367 with the ISO numbers at Rock Auto:
Contact #4 is not used, but would be in the middle if installed. Look carefully at your existing relay to see if the contacts are labeled. If not, they should be the same as the image above.
Here's your previous picture showing where the relay fits. I've added the socket numbers in yellow for your convenience:
As you continue to troubleshoot the lack of power at fuse #18, one word of caution: This MAY be a normal condition if the ECM is not operating properly (for reasons still unknown) and is therefore unable to provide the ground at contact #2 to energize this relay. If the relay is not energized, power will not be sent to fuse #18. In other words, a lack of power at fuse #18 may merely be a symptom of the problem, and not the root cause.
I found some details for you on the socket numbering. Jaguar uses "ISO relay pin numbers", which is 1 through 5. Lots of other relays use a Bosch standard from who knows when, with truly oddball numbers (30, 85, etc.). The relays are pretty much the same internally, but the labels are different. Very confusing. Most online sources only show the confusing Bosch system.
I did find a Wells 1R3367 with the ISO numbers at Rock Auto:
Contact #4 is not used, but would be in the middle if installed. Look carefully at your existing relay to see if the contacts are labeled. If not, they should be the same as the image above.
Here's your previous picture showing where the relay fits. I've added the socket numbers in yellow for your convenience:
As you continue to troubleshoot the lack of power at fuse #18, one word of caution: This MAY be a normal condition if the ECM is not operating properly (for reasons still unknown) and is therefore unable to provide the ground at contact #2 to energize this relay. If the relay is not energized, power will not be sent to fuse #18. In other words, a lack of power at fuse #18 may merely be a symptom of the problem, and not the root cause.
Hello karl
Thank you so much for the diagram
Put a jumper wire between pin 3 and 5 relay #4 throttle body and got power at fuse #18
I know it not the relay relay as I swapped it with the one from the wife car
At least I now know that part of the wiring is ok
New ignition switch should be delivered tomorrow
I decided to replace it since I kept getting key in Ignition Circuit failure
I know I have power at engine control module connector plug pin 134 power to throttle relay i think it is
Now need to work out what other pins to test
on ecm connector plug
Thank you
So much
Cheers Darrol