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PCCM+ with M490 on 1999 car?

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2 captured repliesDiscussion pagination complete · Source accounts, not a confirmed diagnosis

THIS DISCUSSION / SOURCE-DERIVED OVERVIEW

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YOUR RESEARCHPCCM+ with M490 on 1999 car?

Reported or suspected cause

ground wire

Reported cause

No successful repair reported for this finding.

1
Identified cause: 0
Suspected cause: 0
Reported fixes

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Explicit resolution reports before identified causes, performed actions and suggestions. Within each level, matching component labels precede direct query mentions and inherited thread context; successful versus unsuccessful discussion counts, owner confirmations and independent discussion support determine order. This is not a probability of success.

Discussions that report identifying a cause: 1

0 original-poster resolution reports. Counts can overlap; they are not unique people or a success rate.

0 discussions have direct query context; 0 report a fix in that context. Other evidence may inherit the discussion’s subject.

Reported cause · Original poster
Seriously: It was the ground wire from Pin 17.
Original post Read captured discussion
PCCM+ with M490 on 1999 car?

Frequently discussed work

Install wire into the empty #17 slot, grounded it

No successful repair reported for this finding.

0
Reported fixes: 0
Unsuccessful attempts: 1
Discussions

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Discussions that performed work without a confirmed outcome: 1

0 original-poster resolution reports. Counts can overlap; they are not unique people or a success rate.

0 discussions have direct query context; 0 report a fix in that context. Other evidence may inherit the discussion’s subject.

Performed · outcome unconfirmed · Original poster
But, I installed the wire into the empty #17 slot, grounded it with some alligator clips, and it started right up.
Original post Read captured discussion
PCCM+ with M490 on 1999 car?

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Leading evidence: 'ground wire' (1 discussions report identifying this cause; no attributable repair resolution). Across 1 matching discussions, the most frequently mentioned possible cause is 'ground wire' (1 discussions; 1 report identifying it and 0 suggest it). The most frequently discussed action is 'Install wire into the empty #17 slot, grounded it' (1 discussions). For that action, 0 discussions report a resolution and 0 report an unsuccessful attempt. No action has an explicit, attributable resolution report under the current rules. These are forum reports and suggestions, not a confirmed diagnosis.

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1 matching discussions · 2 captured posts examined · 0 partial discussions

Compare 1 other evidence results

Install wire into the empty #17 slot, grounded it

Performed · outcome unconfirmed

No successful repair reported for this finding.

0
Reported fixes: 0
Unsuccessful attempts: 1
Discussions

Read evidence and context

Discussions that performed work without a confirmed outcome: 1

0 original-poster resolution reports. Counts can overlap; they are not unique people or a success rate.

0 discussions have direct query context; 0 report a fix in that context. Other evidence may inherit the discussion’s subject.

Performed · outcome unconfirmed · Original poster
But, I installed the wire into the empty #17 slot, grounded it with some alligator clips, and it started right up.
Original post Read captured discussion
PCCM+ with M490 on 1999 car?

Frequently discussed actions (1)

These are separate views of the same evidence. Frequency alone does not establish a fix, and these counts must not be added together.

Install wire into the empty #17 slot, grounded it

No successful repair reported for this finding.

0
Reported fixes: 0
Unsuccessful attempts: 1
Discussions

Read evidence and context

Discussions that performed work without a confirmed outcome: 1

0 original-poster resolution reports. Counts can overlap; they are not unique people or a success rate.

0 discussions have direct query context; 0 report a fix in that context. Other evidence may inherit the discussion’s subject.

Performed · outcome unconfirmed · Original poster
But, I installed the wire into the empty #17 slot, grounded it with some alligator clips, and it started right up.
Original post Read captured discussion
PCCM+ with M490 on 1999 car?

Reported and suspected causes (1)

These are separate views of the same evidence. Frequency alone does not establish a fix, and these counts must not be added together.

ground wire

No successful repair reported for this finding.

1
Identified cause: 0
Suspected cause: 0
Reported fixes

Read evidence and context

Discussions that report identifying a cause: 1

0 original-poster resolution reports. Counts can overlap; they are not unique people or a success rate.

0 discussions have direct query context; 0 report a fix in that context. Other evidence may inherit the discussion’s subject.

Reported cause · Original poster
Seriously: It was the ground wire from Pin 17.
Original post Read captured discussion
PCCM+ with M490 on 1999 car?

Coverage and how to read this overview

Counts describe captured discussions, not unique people or a diagnosis. Author identities are not reliably stored. Exact duplicate evidence is counted once across matching discussions; one discussion counts at most once per action/state. Multiple repairs reported together remain a combination. Suggestions and failed attempts do not establish a fix. Matches cover whole discussions and can include related faults, model variants and incomplete threads.

2 eligible posts · 0 unverified posts · 1 discussions match the subject in their title or opening post.

Rennlist: 1 discussions

0 evidence records excluded for query context · 0 excluded by outcome qualification · 0 adjusted by outcome qualification.

0 acknowledgements have no verified action link; they do not establish a repair result.

Generation: 20261026T155324Z · outcome-qualification-6. Deterministic extraction; no AI model inference. How we use sources

POST 1 / ORIGINAL POSTEROriginal post

I've scoured all the threads I could find, but I don't see anyone who's got my same configuration. I've got the 6 disk changer and the M490 amplifier in the frunk, but no DSP. The car originally had the PCM 1 system, which was working (mostly) when I removed it. (I say "mostly" because the DVD drive was getting flakey and not reading reliably.) My PCCM+ installation went great ... except I've got no sound. I'm 100% sure that I've got the head unit set to "AMP" in the secret menu, but I'm just not getting any audio output. Also, it seems like I don't need the MOST bridge unit at all, since my car doesn't have any MOST cabling to which it would connect. Can I just omit it? Any hints for this?

POST 2 / ORIGINAL POSTEROriginal post

LOL, I did it. Here's the steps: Fiddle with it for an hour. Search again. Make a post. Go back to the garage. Suddenly reason it out. Seriously: It was the ground wire from Pin 17. I didn't install this because I didn't have DSP, so I thought I didn't need it. Plus, the AMP (Amphenol) connector looked like it oculdn't be disassembled to have a pin added to it, and didn't hvae the "black/red/yellow" wire in it anyway. But, I installed the wire into the empty #17 slot, grounded it with some alligator clips, and it started right up. Also, everything works fine without the MOST module connected at all. Seems like Porsche could document that. Aside from getting confused about the amplifier DSP input grounding, the hardest part was routing the cable from the USB/AUX box to the head unit. The first two paths I found left the cable far too short to connect to the head. The third try just barely made it.

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