CEL- Idle Speed Control Implausible?
Thread Starter
Senior Member
Joined: Dec 2007
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From: Dago, CA
2003 cl55 (sold)
CEL- Idle Speed Control Implausible?
No vacuum leaks, still get 2 codes: P202B-002 Idle speed control implausible: Short circuit to ground or open circuit. P20A2- Idle speed control implausible: Check system for unmetered air. Have had both of these codes since switching to the 80mm TB. Engine idles funny (up and down) sometimes. Sometimes it's fine. Sometimes it feels like it's going to stall at a stop light. Again, no vacuum leaks.... Had the throttle body knife edged (maybe sticking, but it seemed perfectly fine...) Also, had to drill a hole for the PCV vacuum and I noticed that it kind of sits under the throttle plate at idle position (3%) could this be the culprit? TPS sensor? Bad throttle body?
Member
Joined: Sep 2006
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From: San Francisco
AMG's
You have more air going into the intake than the MAF see's. The idle surging is due to the ecu constantly overcompensating while trying to control idle speed. The most likely reason is a vacuum leak. Not necessarily manifold vacuum, anywhere behind the MAF. Intake boot?
Thread Starter
Senior Member
Joined: Dec 2007
Posts: 472
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From: Dago, CA
2003 cl55 (sold)
You have more air going into the intake than the MAF see's. The idle surging is due to the ecu constantly overcompensating while trying to control idle speed. The most likely reason is a vacuum leak. Not necessarily manifold vacuum, anywhere behind the MAF. Intake boot?
MBWorld Fanatic!
Joined: Jun 2006
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'03 E55, Range Rover Sport Supercharged, Ducati 748R
even though it seems unlikely, i've also seen these symptoms caused by a poor fitting inlet over the tb. make sure your y-pipe is mated correctly to the tb inlet.
Thread Starter
Senior Member
Joined: Dec 2007
Posts: 472
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From: Dago, CA
2003 cl55 (sold)
It's on good.... even put an extra clamp on it to help hold it down.... checked for leaks everywhere.... no leaks.
Thread Starter
Senior Member
Joined: Dec 2007
Posts: 472
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From: Dago, CA
2003 cl55 (sold)
.... took off the throttle body, disconnected the PCV hose from the hole and just left it sitting in the engine, put a piece of high temp tape over the hole, drove it around all day today and coming back to the pad, the check engine light went off! It's the damn hole.... thinking that I'll have someone fill that hole with aluminum epoxy and have him redrill the hole for the PCV vacuum away from the butterfly plate like it should be..... should be problem solved.
