Well, today's code is as shown in the header: Leakage Diagnostic Pump Control Circuit Electrical.

This popped up on my 98 540 yesterday, and I thought the CEL would be about my usual catalyst (they're gutted) problem. Pulled out my code reader to verify and I see the new (to me) message. Has anyone seen this one yet, and any ideas on what to look at?

I found a thread on the E46Fanatics site that suggested the following for their cars:
"Try to fix this yourself. Look under the car, behind the passenger rear tire, remove the black plastic shield. Unhook the solenoid (look like a coil of copper wire). Take the solenoid apart at each end (it unclips). Put some dielectric grease (like high quality vasoline) on the end clips so it will not leak, and reassemble. I had the same code on my 2001 and this fix worked.
If this doesn't work, buy a new gas cap.
If that doesn't work, take it to the dealer."

So I tried. After removing the rear passenger tire, I fought with the fender liner for some time before finally getting it off. Nothing electrical in there except for the alarm siren and brake electrical. Has anyone got an idea of where to look for this solenoid (or if it exists on a E39)? The fender liner was a bitch to remove, and I'm done exploring as it's winter in Edmonton, and my garage isn't heated. I don't see the gas cap being a problem, as the code refers to an electrical issue. A single drive cycle causes the CEL to come back on with the same code.

My dealer wants to charge an hour labour just to diagnose the problem. The service advisor has no interest in discussing what the repair might entail, just bring it in and give me $130 and I'll have someone look at it. I guess someone has to pay for the new Dealership...

I'd be very pleased if someone here has any ideas...

Thank you - Jeff
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Well, today's code is as shown in the header: Leakage Diagnostic Pump Control Circuit Electrical.

This popped up on my 98 540 yesterday, and I thought the CEL would be about my usual catalyst (they're gutted) problem. Pulled out my code reader to verify and I see the new (to me) message. Has anyone seen this one yet, and any ideas on what to look at?

I found a thread on the E46Fanatics site that suggested the following for their cars:
"Try to fix this yourself. Look under the car, behind the passenger rear tire, remove the black plastic shield. Unhook the solenoid (look like a coil of copper wire). Take the solenoid apart at each end (it unclips). Put some dielectric grease (like high quality vasoline) on the end clips so it will not leak, and reassemble. I had the same code on my 2001 and this fix worked.
If this doesn't work, buy a new gas cap.
If that doesn't work, take it to the dealer."

So I tried. After removing the rear passenger tire, I fought with the fender liner for some time before finally getting it off. Nothing electrical in there except for the alarm siren and brake electrical. Has anyone got an idea of where to look for this solenoid (or if it exists on a E39)? The fender liner was a bitch to remove, and I'm done exploring as it's winter in Edmonton, and my garage isn't heated. I don't see the gas cap being a problem, as the code refers to an electrical issue. A single drive cycle causes the CEL to come back on with the same code.

My dealer wants to charge an hour labour just to diagnose the problem. The service advisor has no interest in discussing what the repair might entail, just bring it in and give me $130 and I'll have someone look at it. I guess someone has to pay for the new Dealership...

I'd be very pleased if someone here has any ideas...

Thank you - Jeff
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OK - I found the problem, and I'm posting my findings in case the information is of some use to anyone else...

I finally found the leakage diagnostic pump in the rear fender well. I had to remove the driver rear wheel and inner fender to expose the critter, and there is was, attached to a fuel evap canister. The insulation on the wiring to the pump had been damaged due to chaffing, so it was an easy fix to replace the old worn through wires.

Hope this helps someone down the road...

Thanks for posting this.

i think you're talking about the dmtl(diagnostic module for tank leak detection). i see these faults occasionally at work but the problem is usually a missing gas cap or the car being driven without the gas cap in place. good diy though...

i think you're talking about the dmtl(diagnostic module for tank leak detection). i see these faults occasionally at work but the problem is usually a missing gas cap or the car being driven without the gas cap in place. good diy though...

No, the code "P1470" description referred to: Leakage Diagnostic Pump Control Circuit Electrical.

Given that I could find NOTHING at all regarding this particular code on an E39 540, I thought I'd post my findings, as it would have surely saved me some time had the information been available. I didn't think the problem would have been a faulty or missing gas cap, as the description referred to "Control Circuit Electrical", rather than an outright leak. The wiring to the pump seems to lay on the top of the inner fender liner, and after 150,000 km the vibration and chafing defeated the insulation and one conductor. The good news is that I've become a little better at taking out the rear inner fender liners...

I bet that has to do with a pump that aids in checking your gas tank for leaks for the EPA OBD-II standard requirements.

Am I stating the obvious?