Posted by Steve Gittins on July 22, 2009, 10:44 am
Year of Manufacture *: 2001 Engine Code or Type *: RHY ( Optional ) ECU Type: EDC15C2
Morning!
Been having some problems with 3 different 306's. All of them very late (The last 12 mths of 306 manufacture) HDi's with RHY engine code. Bosch EDC15C2 ECU's (the one with three plugs that looks like the early version of what you find on 307's)and all with exactly the same fault.
The cars have all come to us with the Engine management fault light showing. When the codes are downloaded they come up with "Accelerator pedal position sensor range/performance problem".
With the first I checked the signal from both tracks of the APPS with the scope and they both displayed a faultless rise and fall with movement of the cable. I then checked the wiring from APPS to ECU for good plug connections and continuity, All looked good so I checked the signal at the ECU pins and they were identical to that seen at the pins on the APPS. The live date from the ECM also suggested all was OK. Gave the car back to the customer and about 10 days later the light was back on. Same code, re checked all previous checks and everything still looked OK. Out of desperation, although I didn't find any fault with it, I changed the Throttle pot.(New, genuine part) A week later, the light was back on. I then Replaced the wiring from APPS to ECU. 2 weeks later the cars back with the same fault. In desperation I spoke to our local Main dealer who said it must be an ECU fault. They then fitted one but still a few weeks later the fault is back.
At this point the customer had had enough and changed the car! But in the past few moths I have been through the exact same problems with 2 other identical 306's. As with the first everything checks out OK so Ive approached them with a check everything attitude.
The one I have been working on this week had a low output from the Air flow sensor. I thought as its the main player in measuring engine load it could be causing a problem and the ECU is getting confused So I replaced it. The Car is no better although the Air flow sensor is higher its still not as high as I would expect. Ive checked for restriction in the intake and exhaust/turbo, All seems fine and compression seems good with no sign of issue there. The car actually performs very well, probably as well as a 306 Hdi has ever gone.
So Ive checked right through the Live Data and the only issue I can see is some poorly injectors. The Inj corrections are hovering around Cyl1 2.2, Cyl2 -0.8, Cyl3 3.6 Cyl4 0.5. I fitted the spill bottles and I'm getting cyl1 9 divisions Cyl2 7.5 div Cyl3 10.5 div, Cyl4 0.5 which would support the correction figures and show they need some attention.
The rail pressure seems to Max out at about 950 which I thought was slightly low but could be due to injectors??
I don't want to be giving the customer a huge bill for injectors and again fail to fix the fault.
Can anyone point out any errors in what I have done? Does anyone have any idea's? A second opinion? Would the injectors be causing a APPS fault somehow? Any other idea's? Anyone else had this fault (If Ive seen 3 there must be others) All help would be very much appreciated.
Last night I re checked the earth on the APPS. With the engine running, operating the throttle and with key on engine not running, working the APPS through its range there's 15mV across the earth pin on the APPS and the bat' neg' terminal. Would this be enough to cause problem?
I wasn't sure so I thought I would add an extra known good earth. Autodata doesn't have a wiring diagram for the 3 plug system on a 306, Only the single plug system. The nearest I can find is a 307 but I'm slightly suspicious of its accuracy and don't trust it. I checked the wiring diagram and (assuming its right) the earth goes through the ECU. I presume this is just for convenience and ease of wiring as the loom just goes to one place? is there any other reason.
So does any one have a correct diagram for the 306 with this 3 plug ECU? Is the 15mV across the earth too much? How do I go about correcting this? Any other idea's?
Steve scope all the wires at the APP and 'wiggle' test the loom, rock the engine with the clutch or drive it and watch for problems. Regards, Sean
Fixed #
Posted by Steve Gittins on February 8, 2010, 6:15 pm, in reply to "Re: Peugeot 306 RHY 2001 - APPS fault? #" Message modified by board administrator February 9, 2010, 6:45 pm
Well it looks like its fixed and the answer was in the posts above. I had ran out of ideas on this one so despite the fact the APPS earth tested OK I re checked all the earth points I could find around the car. They all looked clean and good. I then physically removed and checked them, Again all appeared fine except for a multi earth point below the battery which was slightly corroded but not bad. I cleaned it up and sent the car back to customer. The car was in last week and when I asked the customer he said its been faultless.
I assume that the earth point must be an ECU earth of some form that has caused an issue and made the ECU flag the APP code.
on July 22, 2009, 4:16 pm, in reply to "