Member Since: 19 Jan 2015
Location: Caerphilly
Posts: 2256
I’m doing my absolute best to keep up also but more determined than ever to get to the bottom of this once and for all. I’ve ordered that canbus test box you said about. Looking for the test probe now also. I am determined to get better at this side of fault finding. I’m pretty good with boilers but cars are a whole new level. Jarrod
Current : D3 2007 HSE - AKA the lemon
-beanie grille
-detango with led bulbs
-club body off rebuild. TWICE.
26th Jul 2020 5:03 pm
PROFSR G
Member Since: 06 Mar 2017
Location: Lost
Posts: 4580
gstuart wrote:
Hiya den
Respect my friend and can I say that lot went over my head
Took a screen shot if that’s ok so can try and read it a few more million times to see if it clicks
Really like learning new things , hats off to u mate as always with ur expertise
It might be about to go over my head too Gary yµ (idµ - eAµ) ψ=mψ
26th Jul 2020 5:15 pm
gstuart
Member Since: 21 Oct 2016
Location: kent
Posts: 13576
U and me both
Indeed ref boilers , including the wiring which I have no problems tracing faults in heating systems and am the same with trying to learn as much as I can on these discos
tester , it’s made by sealey , plus the box having 2 x obd connectors u can plug ur iid in at the same time , just felt it makes life a lot easier using the box
U can use ordinary multimeter test leads for the box, don’t need the banana connections
Member Since: 21 Oct 2016
Location: kent
Posts: 13576
PROFSR G wrote:
gstuart wrote:
Hiya den
Respect my friend and can I say that lot went over my head
Took a screen shot if that’s ok so can try and read it a few more million times to see if it clicks
Really like learning new things , hats off to u mate as always with ur expertise
It might be about to go over my head too Gary
,
Can I take a guess on this please, so by putting one lead on the negative lead at the battery and the other on the various connections of the fuel pressure sensor are u therefore testing the resistance as it goes from one test probe to the other via the ECM please
Including looking for the canbus 5Vdc signal that comes from the ECM, does that sensor work like a thermistor as in the ohms change as the internal diaphragm changes as pressure changes
Plus , looking for the signal as it goes to the sensor then back to the ECM with the earth signal sharing each side of the wires , so need to ensure wires aren’t touching each other to short
Hope u don’t get a headache with me asking daft questions, lol
Thks as always
26th Jul 2020 5:27 pm
PROFSR G
Member Since: 06 Mar 2017
Location: Lost
Posts: 4580
Discomadness wrote:
Hi prof.
Ok retested. Here’s the figures. Didn’t realise my fluke auto ranges.
12.54v
Engine warm
Voltage on
White/green 4.9v
Brown/green 0.018
Yellow/green 5.0v
Voltage off
White/green 0v
Brown/green 0v
Yellow/green 0v
Continuity ign off
White/green 1.383
Brown/green beep .000
Yellow/green .190
Continuity short
W/g-br/g 1.384
Br/g-y/g nothing .189
W/g-y/g nothing 1.422
So that's looking better but still an anomaly of slightly lower resistance. Did you try the voltage test with the engine running? You may have to pierce the cables with a probe if the engine dies with the plug off.
I'm just wondering if there is partial or intermittent contact between W/G & Y/G but check the voltage as above first. You may in the end have to pull the ECM plug and test resistance between W/G & Y/G and the FRPS plug.
The readings with plugs out using the same ohms setting should be 000 on each individual wire. If you then try crossing one probe to another wire there should be no continuity unless the tested wires are shorting!yµ (idµ - eAµ) ψ=mψ
26th Jul 2020 5:48 pm
gstuart
Member Since: 21 Oct 2016
Location: kent
Posts: 13576
Also found this ref ECM connectors , hoping that it may be of use
Interesting about if software is updated that on the 15th time the ECM needs to be replaced
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Last edited by gstuart on 26th Jul 2020 6:18 pm. Edited 1 time in total
26th Jul 2020 6:15 pm
Discomadness
Member Since: 19 Jan 2015
Location: Caerphilly
Posts: 2256
I’ve just tested it with engine running. I unplugged it. Car had a fit but kept running. 5v on white/green and yellow/green. 0.015v on brown/green.Jarrod
Current : D3 2007 HSE - AKA the lemon
-beanie grille
-detango with led bulbs
-club body off rebuild. TWICE.
26th Jul 2020 6:16 pm
wedgev8
Member Since: 17 May 2019
Location: Kerpen
Posts: 181
For all , Here are some information about the injection system. I have read this before fault searhing.
Member Since: 17 May 2019
Location: Kerpen
Posts: 181
Discomadness wrote:
I’ve just tested it with engine running. I unplugged it. Car had a fit but kept running. 5v on white/green and yellow/green. 0.015v on brown/green.
This is correct when unplugged. Please measure while plugged in and engine running.
Yellow/green should have 5V and White/Green should have 1 to 1.5V when idling.
Brown/Green is Signal earth or Mass.
26th Jul 2020 6:45 pm
PROFSR G
Member Since: 06 Mar 2017
Location: Lost
Posts: 4580
Discomadness wrote:
I’ve just tested it with engine running. I unplugged it. Car had a fit but kept running. 5v on white/green and yellow/green. 0.015v on brown/green.
Are you certain of these figures Jarrod? The voltage should be 5.0 volts on the supply side, and something like 0.5 v on the output side!
If you use the centre pin (No'2) of the plug as earth and with the ign on probe pins 1 and 3 you should see 5v on the supply terminal and 0.5 on the output back to the ECM. If both are reading 5v there is a short from the supply side to the output side before the signals reach the rail sensor.
EDIT:
With engine running and FRPS plugged in!yµ (idµ - eAµ) ψ=mψ
Last edited by PROFSR G on 26th Jul 2020 7:23 pm. Edited 1 time in total
26th Jul 2020 7:11 pm
Discomadness
Member Since: 19 Jan 2015
Location: Caerphilly
Posts: 2256
Engine running wire stabbed
White green 1.007
Yellow green 4.98
Brown green 0.015Jarrod
Current : D3 2007 HSE - AKA the lemon
-beanie grille
-detango with led bulbs
-club body off rebuild. TWICE.
26th Jul 2020 7:20 pm
wedgev8
Member Since: 17 May 2019
Location: Kerpen
Posts: 181
Perfect!
And your fault Codes and limb mode???
26th Jul 2020 7:24 pm
Discomadness
Member Since: 19 Jan 2015
Location: Caerphilly
Posts: 2256
No limp mode as yet but that injector I’ve changed hasn’t trimmed in yet. They take about 100 miles or so. This one crops up though but no limp.
EDIT:
I’ve been taking some of the tape off the harness to test and found a few stab holes in cables probably from someone’s attempt to get to the bottom of this or other faults previously. The rail pressure sensor has white paint on it as a breaker would use.Jarrod
Current : D3 2007 HSE - AKA the lemon
-beanie grille
-detango with led bulbs
-club body off rebuild. TWICE.
26th Jul 2020 7:28 pm
PROFSR G
Member Since: 06 Mar 2017
Location: Lost
Posts: 4580
I can't see anything wrong with that, Y/G is the supply side so 4.98 is good. W/G is the signal back to the ECM and this will fluctuate depending on throttle position and load to a max of around 1.5 v I think.
So if the ECM is seeing a spike in the return voltage, why and where is it coming from?
I can only suggest the two wires have chaffed somewhere between the FRPS and the ECM and are perhaps
making an intermittent contact. Or, further back in the loom towards the ECM the same chaffing has occurred between the W/G and another wire. yµ (idµ - eAµ) ψ=mψ
26th Jul 2020 7:32 pm
Discomadness
Member Since: 19 Jan 2015
Location: Caerphilly
Posts: 2256
I’m finding stab holes and scrapes/cuts to the insulation all over the loom. Jarrod
Current : D3 2007 HSE - AKA the lemon
-beanie grille
-detango with led bulbs
-club body off rebuild. TWICE.
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