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Discussion Starter #1
Hi everybody I know that this is a regular topic but feel that I am chasing my tail and getting nowhere.
I own a normally very nice well maintained 2006 Saab 9-3 1.9 diesel automatic estate. Up until now it has given me no trouble in the two years of ownership with 94000 miles on the clock.
A couple of weeks ago I went to start the car and nothing! turned the key and MOST of the normal dashboard lights came on as normal EXCEPT the Engine managemnet light and diesel preheater light, turned the key all of the way and it did not turn the engine over, also fuel gauge is reading empty despite having 3/4 tank .
After reading various posts and watching youtube I have done the folloeing:
Checked battery fully charged (2 years old)
Relays all work (tested for clicking)
Running a wire across terms 87/30 on starter relay will crank the engine
Running a wire across ECU relay terminals 30/87 gives nothing but activates something that sounds like another relay.
Jumping a wire across the main Traction control pump unit terminals 1/13 & 2/14 does nothing (youtube stated that this eliminates this module from being faulty if the car does not start)
I have had the ECU professionally tested (£76 ) all OK
I have sprayed ECU terminal blocks with contact cleaner
I have cleaned back the battery / bodywork earth connection
SID gives all checks OK
Engine diagnostic plug does not talk to my Code reader (has done previously), Code reader keeps requesting me to connect.
Am at a loss as to what to try next..... My guess is that there still is an ECU issue perhaps a broken power feed. but cannot find a wiring diagram of socket to try voltmeter.
Have finally found an auto electrician who is going to take a look but don't have a lot of confidence that he is going to be able to pin this down as only a normal vehicle technician (no Tech 11 which I think is going to be needed).
Anybody know a definative way of testing ignition switch without dismantalling the console?
Any suggestions welcome...
Thanks in advance
 

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Sounds like no comm with the ECU, here is the list of powers and grounds, check all of them first, and if they check ok next check continuity on the communication wires, and if all checks ok then bad ECU.
Powers pins B1,B5,B28
grounds pins B2,B4,B6
 

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Discussion Starter #3
Sounds like no comm with the ECU, here is the list of powers and grounds, check all of them first, and if they check ok next check continuity on the communication wires, and if all checks ok then bad ECU.
Powers pins B1,B5,B28
grounds pins B2,B4,B6
Thanks will take a look in the morning
Sounds like no comm with the ECU, here is the list of powers and grounds, check all of them first, and if they check ok next check continuity on the communication wires, and if all checks ok then bad ECU.
Powers pins B1,B5,B28
grounds pins B2,B4,B6
Silly question perhaps but there are two connector blocks to ECU is it the smaller or larger one that has the pins for testing... What was interesting was the ECU had coroded connector pins on the unit when I took it out (came back clean after testing) which is why I sprayed the blocks with contact cleaner
 

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Well, if u have corrosion its a kind obvious .. ecu side or connector side ?
connector B is the one with more pins ..
 

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Discussion Starter #5
Well, if u have corrosion its a kind obvious .. ecu side or connector side ?
connector B is the one with more pins ..
Thanks.. That was what I thought and was really optomistic when refitted ECU after it had returned cleaned and I had cleaned the sockets but no different, so not now so obvious...lol
 

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Discussion Starter #6
Thanks.. That was what I thought and was really optomistic when refitted ECU after it had returned cleaned and I had cleaned the sockets but no different, so not now so obvious...lol
Thie pins on the ECU showed slight green corrosion but the testing facility cleaned them prior to testing
 

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just dont trust these facilities too much, look carefully u could be missing a pin thats completely gone, or inside the connector the pins has corroded off the wire , or corrosion got inside the ecu .
 

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New ECU time. Shame on Saab for putting it in such a rubbish place.
 
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@Saab Dinosaur The diesel suffers with a broken wire around the gearbox turret area within the loom,which powers the relay..

 

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Discussion Starter #10
Thanks will take a look in the morning

Silly question perhaps but there are two connector blocks to ECU is it the smaller or larger one that has the pins for testing... What was interesting was the ECU had coroded connector pins on the unit when I took it out (came back clean after testing) which is why I sprayed the blocks with contact cleaner
OK no power appears to be getting to ECU have checked all pins and no power is showing at the terminal so it looks like possibly ignition switch as presumably that is the next link in the chain?
 

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Discussion Starter #11
@Saab Dinosaur The diesel suffers with a broken wire around the gearbox turret area within the loom,which powers the relay..

Relay appears to be getting power as checked those connections but thanks for the suggestion
 

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Discussion Starter #13
Relay appears to be getting power as checked those connections but thanks for the suggestion
Which now begs the question if power is getting to the relays both terminals 30 & 85 on each of the ignition controlled relays is it the ignition switch? as surely no power would be getting through if the ignition switch were faulty? the other mystery is that the fuel gauge is reading empty, power is getting to it as the needle twitches when power turned on....looks like I am going to have to let the auto electrician track down the problem as I am getting fed up with the thing..... Oh and eliminated any chance of it being the battery as not only is it fully charged but also tried jump starting with my wife's car .. no difference.
 

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Discussion Starter #14 (Edited)
So no power at the three pins with the ignition ON ?
I assume that you mean the ECU pins, despite cleaning the socket connectors again with contact cleaner ...no nothing... when I try to "jump" the ecu relay I only get the relays clickingI read on one of these forums that if the car started doing this it would indicate a ccommon broken wire on the feed to the relays... Relays show power at terminals 30 and 85....on ECU relay, starter relay and ignition relay. Presumably this narrows the fault down to between the ECU relay and the socket connector on the ECU
 

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If u have power at both pins 30&86 then it indicate absence of the controlled side ground , wether it is due a bad ignition switch or anything else.
Which relays exactly u r talking about ?
 

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Discussion Starter #16
If u have power at both pins 30&85 then it indicate absence of the controlled side ground , wether it is due a bad ignition switch or anything else.
Which relays exactly u r talking about ?
R11 ignition relay, R7 Engine management main relay, R8 starter relay
 

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First recheck fuse 4 in the big fuse box.
Then Lets focus on relay 7 (main relay).
Jump terminals 30&87, and see if the car starts .
 

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Discussion Starter #18
First recheck fuse 4 in the big fuse box.
Then Lets focus on relay 7 (main relay).
Jump terminals 30&87, and see if the car starts .
OK Fuse four is fine (swapped with another) also power getting to fuse when ignition turned on, jumped 30/87 no start but ECU light came on on dashboard (hadn't noticed it before but then hadn't looked and I get a humming sound like a pump is working (still nothing on fuel gaauge)
 
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