Member
Hi all,
My transmission has gone into fail safe mode with the 'red cog of death.'
I pulled the code and it says 00506, the possible fault causes listed are:
-Line faulty
-Line has short circuit to ground/voltage
-Nominal and actual current values implausible
-Clutch branch not adequately bled
-Teach-in for clutch not okay
-Clutch valve faulty
-Control Unit faulty
Now, my voltage is low, with the recorded power supply being between 11.67 and 12.17 volts during testing.
The hydraulic pressure is also low, reading between 52.4 bar and 62.7 bar. I believe nominal should be 74 bar?
I've tried to re teach-in the clutch, no change. I've checked and rechecked all connectors with no change or effect.
The only non responsive test function is when you check the control unit (SMG ECU), the test never responds and I need to restart the ISTA program.
I've test the accumulator and it failed the pressure test but I'm unsure if this is due to low voltage or if it's actually faulty.
The only other instance I've found of this fault code was rectified by replacing the SMG ECU.
Can anyone shed any light on this? My dealer is not very helpful BTW.
Thanks in advance!
Member
Whacky voltages scan cause whacky symptoms. The first thing is to charge the battery so the voltage is in the ballpark. Then clear the code and rescan.
Wagon meister :)
BMW Tech Expert
+1
As part of any testing, you need to have a battery tender hooked up to keep the voltage stable while doing this.
Darin
Current:
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05 325it Electric Red(438)/Gray(N6TT) ZCW, ZSP 5sp Manual Back set cover, trunk mat, Euro Infra-Rot front windshield, and mud flaps! Mr. Wagon My new Winter car.
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Past:
95 318is Montreal Blue Met (297)/Beige(K1SN) RIP, killed by an Idiot.
84 M535i gray market Burgandy Rot Met/Black Leather Lowered by Intrax on bilies, poly everywhere, B&B cat back system, K&N, and a hitch! Da Beast - Still running w/400k+!
91 316i euro Tizianrot/Gray cloth - E-36 w/M-40 RIP, but great on gas! Best was 38 MPG
82 528i euro Saphire Blue Met/Blue Leather RIP
79 525 euro Green/Green RIP
79 318 Silver/Black - The first one that got it all started
M-Flight Member
Member
Thanks all,
I have a new battery on the way. I tried the tender but at maintenance setting it wouldn't get over 12.4 volts and on charge, it's a pulse charger so that wouldn't help either. A new battery is always a feel good measure anyway so why not?
I'll update once the battery is ruled out.
Member
Okay so good news, bad news update.
Good news? I have a new battery installed and the car has been made aware of this correctly. Static voltage is now 12.7 (ish).
Bad news? Stupid fault code is still there.
For some reason, I can't clear the last logged iteration, which means the test result still only shows the last time it occurred and the last voltage and pressure associated.
I ran through every other rest I could think of, voltages at sensors and control unit, shift functions, pressure at accumulator instead.
The accumulator test failed again with a reported preload pressure (28 bar) below the setpoint point value (29-45 bar)
The suggested action is to replace the accumulator.
The fault code still shows the clutch valve as faulty.
When running the suggested test steps, the control unit test fails to respond. The voltage at control unit test is correct but I can't get a response to rule out whether or not the control unit itself may be the issue and not the clutch valve.
SO frustrated at the moment.
Has anyone else had any similar experience? Or with this fault code?
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