[amanzin]

Can anyone help with this combination of errors? 2ACC, 2ACB, A0B4. Car cranks, but won't start.

I have a 2008 328xi E91 N52 wagon. I did not drive it for a while, and the battery, which was old, died. I tried charging it, but it was really dead. I bought a new battery and successfully registered it with the ProTool app. Now I have several new errors, and the car cranks just fine, but it will not start.

CAS [CAS] | A0B4: Engine start, starter operation
DME/DDE [MSV80] | 2ACC: DME master relay, shift delay
DME/DDE [MSV80] | 2ACB: DME master relay, activation
EGS [GS1912] | 578E: Gearbox oil: wear (Okay, understood, I need to change the fluid)

I replaced the blue DME relay with a new BMW part, but that did not eliminate or change any of the errors. Once you've removed a relay, can you test it to see if it works?

I don't know if the CAS and DME errors codes are independent from each other, or if one is causing the others. Does anyone have any advice on what to try next?

Thanks in advance.

[gbalthrop]

Originally Posted by amanzin

... 2ACC, 2ACB, A0B4. Car cranks, but won't start... 2008 328xi E91 N52 wagon...
I replaced the blue DME relay with a new BMW part, but that did not eliminate or change any of the errors. Once you've removed a relay, can you test it to see if it works?...

The CAS Error, A0B4 is related to earlier issues when pressing START button did NOT Crank Starter. You could CLEAR that code and see if it returns.
The TWO codes that are clues for what to check related to current "Crank, NO Start" issue are the two DME Codes related to DME Main Relay. That relay is supposed to supply power to the DME (Engine Control Module) when ignition is ON.

STEP 1: Use a Multimeter to test for voltage at sockets of fuse F37 on the JB Fuse Panel, with Ignition ON. One of the two sockets (with fuse removed) should have battery voltage in reference to Chassis Ground (Red Meter Probe on fuse socket & Black Meter Probe contacting good chassis ground --unpainted Metal). Meter on DC Volts, 20 Volts or less "Range". This is to CONFIRM that there is NO Power Supply to the DME via the Main Relay.

STEP 2: Test BOTH fuse F37 (30-Amp) and F4 (10-Amp) visually, AND electrically (testing for continuity between the two fuse spades with Multimeter (0 Ohms resistance between spades). I will attach ISTA wiring diagram and fuse location diagrams to NEXT Post.

Post back with Results of those tests AND answers to following:
1) Make/Model of Scan Tool or diagnostic software (INPA/ISTA) available to you;
2) If you have a Multimeter;
3) If you have any questions regarding HOW to test using multimeter, for (a) DC Volts, (b) Continuity/ Ohms Resistance.

The DME Main relay is soldered to the JB (Junction Box) Circuit Board. If the "blue relay" you changed was in the E-box under the hood, THAT is the VVT/ Valvetronic Relay, and has NOTHING to do with the 2ACC & 2ACB codes. The DME Main Relay SELDOM fails. Wiring/ Connectors related to Activation of the DME Main Relay (connections to the JB Fuse Box) are usually the cause of Relay NOT being activated (and powering F37 socket).

I would suggest NOT disconnecting anything other than F4 & F37 until "Next Steps" are suggested.
George

[gbalthrop]

Attached are ISTA ScreenPrints related to DME Main Relay & F4, F37 Power Supply to DME, per prior post.
George

[amanzin]

Thanks so much for the detailed information. I'll try what you suggested.

I am using the Bimmergeeks ProTool software via USB on my phone. I did try clearing errors, but they all come back.

I do have a multimeter. I don't see the brand name on it anymore, but the item codes printed on it are E229696 and DT830.

I'll report back!

[amanzin]

Hi George,

I found no Volts (-0.09) on the F37 socket, which looked pretty clean. I found 12.5 Volts on the F4 socket, which also looked pretty clean. Both fuses worked, however the F4 fuse had some discoloration, maybe from heat. It's the top fuse with the darker contacts in the attached photo (sorry for the focus). I put a new fuse in F4, cleared errors, and read them again, and they came back the same.

I noticed some white corrosion on sockets 47 and 48. The lower one was particularly bad.

I should also say that I think there is some water penetration from the rear window, and when I changed the battery a while ago, the cavity that it sits in was a little wet.

How do I fix the problem with F37?

Thanks!

[amanzin]

Hey George,

Thanks for your help so far--I really appreciate it. I'm not sure if I posted my last replies in a way that notifies you. Anyways, both fuses 4 and 37 work just fine, although the F4 fuse appeared to have some heat discoloration. I switched it out for a new one just in case (and then I cleared all errors, and they came back the same). The voltage through F4 socket is fine (12.5), but there's none (-0.09V) through the F37 socket. Any idea what I should do next if there's no voltage on the F37 socket?

Thanks,

Ari

Originally Posted by gbalthrop

The CAS Error, A0B4 is related to earlier issues when pressing START button did NOT Crank Starter. You could CLEAR that code and see if it returns.
The TWO codes that are clues for what to check related to current "Crank, NO Start" issue are the two DME Codes related to DME Main Relay. That relay is supposed to supply power to the DME (Engine Control Module) when ignition is ON.

STEP 1: Use a Multimeter to test for voltage at sockets of fuse F37 on the JB Fuse Panel, with Ignition ON. One of the two sockets (with fuse removed) should have battery voltage in reference to Chassis Ground (Red Meter Probe on fuse socket & Black Meter Probe contacting good chassis ground --unpainted Metal). Meter on DC Volts, 20 Volts or less "Range". This is to CONFIRM that there is NO Power Supply to the DME via the Main Relay.

STEP 2: Test BOTH fuse F37 (30-Amp) and F4 (10-Amp) visually, AND electrically (testing for continuity between the two fuse spades with Multimeter (0 Ohms resistance between spades). I will attach ISTA wiring diagram and fuse location diagrams to NEXT Post.

Post back with Results of those tests AND answers to following:
1) Make/Model of Scan Tool or diagnostic software (INPA/ISTA) available to you;
2) If you have a Multimeter;
3) If you have any questions regarding HOW to test using multimeter, for (a) DC Volts, (b) Continuity/ Ohms Resistance.

The DME Main relay is soldered to the JB (Junction Box) Circuit Board. If the "blue relay" you changed was in the E-box under the hood, THAT is the VVT/ Valvetronic Relay, and has NOTHING to do with the 2ACC & 2ACB codes. The DME Main Relay SELDOM fails. Wiring/ Connectors related to Activation of the DME Main Relay (connections to the JB Fuse Box) are usually the cause of Relay NOT being activated (and powering F37 socket).

I would suggest NOT disconnecting anything other than F4 & F37 until "Next Steps" are suggested.
George