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Volvo XC90 Drivability issues and communication fault codes
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akmotcentre
- Newbie
- Posts: 3
- Joined: Thu Aug 19, 2021 4:26 pm
Volvo XC90 Drivability issues and communication fault codes
Hi,
I have a Volvo XC90 automatic with drivability issues,
On the high speed CAN network we have the following
1. Engine ECU
2. Transmission ECU
3. ABS ECU
4. Differential Module
5. CEM
The fault codes on these modules are
1. Engine - no comms with transmission
2. Transmission - no comms with engine
3. ABS - no comms with engine
4. Diff - No fault codes with communication with any ecu
5 - CEM - no comms with engine.
We have checked lives and grounds at the engine ecu and they are fine. We also disconnected Engine ecu plug and we get a similar pattern.
Any guidance on if the waveform can cause drivability issues and what could be causing the signal to go up.
Thank you for your help
Anand
I have a Volvo XC90 automatic with drivability issues,
On the high speed CAN network we have the following
1. Engine ECU
2. Transmission ECU
3. ABS ECU
4. Differential Module
5. CEM
The fault codes on these modules are
1. Engine - no comms with transmission
2. Transmission - no comms with engine
3. ABS - no comms with engine
4. Diff - No fault codes with communication with any ecu
5 - CEM - no comms with engine.
We have checked lives and grounds at the engine ecu and they are fine. We also disconnected Engine ecu plug and we get a similar pattern.
Any guidance on if the waveform can cause drivability issues and what could be causing the signal to go up.
Thank you for your help
Anand
- Attachments
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- Volvo_XC 90_2008_Diesel_20210826-0004.psdata
- (305.73 KiB) Downloaded 265 times
Re: Volvo XC90 Drivability issues and communication fault codes
Hi.
You need to determine which of the electronic components introduces distortion into the signal form.
To do this, you need to turn off the CAN POWERTRAIN ECU - one by one.
This can be done on the CEM module connectors C and D, or on the CAN 53/352 and 53/353 cross.
You need to determine which of the electronic components introduces distortion into the signal form.
To do this, you need to turn off the CAN POWERTRAIN ECU - one by one.
This can be done on the CEM module connectors C and D, or on the CAN 53/352 and 53/353 cross.
- Attachments
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akmotcentre
- Newbie
- Posts: 3
- Joined: Thu Aug 19, 2021 4:26 pm
Re: Volvo XC90 Drivability issues and communication fault codes
Thank you very much for your reply.
After disconnecting connector 54/57.1 which goes to the transmission loom, the CAN signals were nice and clean.
We checked power and ground to the transmission and they were fine.
Plug 54/57.1 has 8 pins
1. Supply - good
2. empty
3. Gear selector module
4. CEM
5. Engine ECU
6. CAN H
7. CAN L
8. Earth
Would it be safe to say that the transmission module is causing the communication problems or could I be getting interference from 3. Gear selector module.
Thanks
After disconnecting connector 54/57.1 which goes to the transmission loom, the CAN signals were nice and clean.
We checked power and ground to the transmission and they were fine.
Plug 54/57.1 has 8 pins
1. Supply - good
2. empty
3. Gear selector module
4. CEM
5. Engine ECU
6. CAN H
7. CAN L
8. Earth
Would it be safe to say that the transmission module is causing the communication problems or could I be getting interference from 3. Gear selector module.
Thanks
Re: Volvo XC90 Drivability issues and communication fault codes
Such a change in the signal on the CAN bus can trigger a pulse energy consumer of sufficient power.
There is no such consumer in the ECU Gear selector module.
In the ECU TCM - there are (electric valves).
First of all, you should check again the reliability of the contact pin8 TCM, measure the voltage ,try to duplicate the wire .
Try to connect a sufficiently large electrical load to the wire as an emulator when the TCM connector is disconnected.
You can connect current pliers to the TCM power wire and compare the frequency of interference and the frequency of increasing current consumption by a specific ECU.
There is no such consumer in the ECU Gear selector module.
In the ECU TCM - there are (electric valves).
First of all, you should check again the reliability of the contact pin8 TCM, measure the voltage ,try to duplicate the wire .
Try to connect a sufficiently large electrical load to the wire as an emulator when the TCM connector is disconnected.
You can connect current pliers to the TCM power wire and compare the frequency of interference and the frequency of increasing current consumption by a specific ECU.
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akmotcentre
- Newbie
- Posts: 3
- Joined: Thu Aug 19, 2021 4:26 pm
Re: Volvo XC90 Drivability issues and communication fault codes
Thank you very much,
I have enjoyed reading your replies and have learnt a lot. The car has gone back to the customer and I will ask him to come back so I can compare current readings to the interference. This be very interesting to see just for my own knowledge.
Thank you
Anand
I have enjoyed reading your replies and have learnt a lot. The car has gone back to the customer and I will ask him to come back so I can compare current readings to the interference. This be very interesting to see just for my own knowledge.
Thank you
Anand