XC70: Electrical - no communication with engine ECU

weef · Sep 24th, 2015, 15:09

Hi, after an engine change on a 2009 V70 2.0D the vehicle will not start. It appears to be dead, will not crank over, when checked with a Snap On Modus Ultra there was no communication with the engine ECU, though it will communicate with the other on board systems. The fuses associated with the engine ECU are OK. My usual technical fallback (Autodata) proved to be scant on information regarding ECU pinouts as I want to check that supplies and earths are present. Any advice on this problem is welcome and any wiring diagrams / pinout information sources will be appreciated.

Thanks Weef.

KBB · Sep 24th, 2015, 21:10

usually if a scan tool will not communicate with one or more modules then I suspect that particular ECU is not fully powered up so I would check all power supplies and grounds associated with that ECU.

If as you say this is after an engine change then good chance a ground cable is not been replaced.

weef · Sep 24th, 2015, 22:09

thanks for the quick reply, your train of thought is the same as mine hence I now need a source of a wiring diagram and the ecu pinout information, can you help with this?.

Clan · Sep 24th, 2015, 22:13

Quote:

Originally Posted by weef

Hi, after an engine change on a 2009 V70 2.0D the vehicle will not start. It appears to be dead, will not crank over, when checked with a Snap On Modus Ultra there was no communication with the engine ECU, though it will communicate with the other on board systems. The fuses associated with the engine ECU are OK. My usual technical fallback (Autodata) proved to be scant on information regarding ECU pinouts as I want to check that supplies and earths are present. Any advice on this problem is welcome and any wiring diagrams / pinout information sources will be appreciated.

Thanks Weef.

You will need to take it to a volvo dealer for an ECU software reload , it can loose it's memory if left unpowered for a length of time ..

weef · Sep 24th, 2015, 22:36

The car arrived to me with the battery having been disconnected by the recovery operators, the timing belt had snapped, and by the time a replacement engine was sourced and fitted it was about 15 days. Do you think that would have been too long to be powered down?. I still would like to check the ECU power and earth connections before I go down the dealer route, hence the request for a wiring diagram.

KBB · Sep 25th, 2015, 08:55

As a quick test when the key is turned to position 2 the EML should come on for the self bulb test and then go out, if the is no MIL activity at key on then its a good indicator that the ECU is not powered up either a missing power supply or ground. The ECU has 3 pins which are grounded they run into a splice and then terminate to ground on a single wire. The ground point is 31/XX5 and is located on the inner wing area just back from the front left head light unit.

weef · Sep 25th, 2015, 18:57

There is no key as such, only a transponder type, and to power up the dash lights the "key" is pushed into its port, clutch pressed and the start button pressed. The multiple earth point on the inner wing is good. Can you tell me which pins these earths, and which pins the power are on at the ECU ?.

Sep 24th, 2015, 15:09	#1
weef New Member Last Online: Nov 15th, 2015 20:00 Join Date: Sep 2015 Location: moffat	no communication with engine ECU Hi, after an engine change on a 2009 V70 2.0D the vehicle will not start. It appears to be dead, will not crank over, when checked with a Snap On Modus Ultra there was no communication with the engine ECU, though it will communicate with the other on board systems. The fuses associated with the engine ECU are OK. My usual technical fallback (Autodata) proved to be scant on information regarding ECU pinouts as I want to check that supplies and earths are present. Any advice on this problem is welcome and any wiring diagrams / pinout information sources will be appreciated. Thanks Weef.

Sep 24th, 2015, 22:09	#3
weef New Member Last Online: Nov 15th, 2015 20:00 Join Date: Sep 2015 Location: moffat	v70 Electrical- no comms withengine ECU thanks for the quick reply, your train of thought is the same as mine hence I now need a source of a wiring diagram and the ecu pinout information, can you help with this?.

Sep 25th, 2015, 08:55	#6
KBB Master Tech Last Online: May 18th, 2020 10:57 Join Date: Dec 2006 Location: On Contract Dubai Automotve Technical Academy	As a quick test when the key is turned to position 2 the EML should come on for the self bulb test and then go out, if the is no MIL activity at key on then its a good indicator that the ECU is not powered up either a missing power supply or ground. The ECU has 3 pins which are grounded they run into a splice and then terminate to ground on a single wire. The ground point is 31/XX5 and is located on the inner wing area just back from the front left head light unit. Last edited by KBB; Sep 25th, 2015 at 09:14.

Sep 24th, 2015, 21:10	#2
KBB Master Tech Last Online: May 18th, 2020 10:57 Join Date: Dec 2006 Location: On Contract Dubai Automotve Technical Academy	usually if a scan tool will not communicate with one or more modules then I suspect that particular ECU is not fully powered up so I would check all power supplies and grounds associated with that ECU. If as you say this is after an engine change then good chance a ground cable is not been replaced.

Sep 24th, 2015, 22:36	#5
weef New Member Last Online: Nov 15th, 2015 20:00 Join Date: Sep 2015 Location: moffat	The car arrived to me with the battery having been disconnected by the recovery operators, the timing belt had snapped, and by the time a replacement engine was sourced and fitted it was about 15 days. Do you think that would have been too long to be powered down?. I still would like to check the ECU power and earth connections before I go down the dealer route, hence the request for a wiring diagram.

Sep 25th, 2015, 18:57	#7
weef New Member Last Online: Nov 15th, 2015 20:00 Join Date: Sep 2015 Location: moffat	There is no key as such, only a transponder type, and to power up the dash lights the "key" is pushed into its port, clutch pressed and the start button pressed. The multiple earth point on the inner wing is good. Can you tell me which pins these earths, and which pins the power are on at the ECU ?.

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