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Message: Diagnosis Gotchas
Changed By: Jayusa123
Change Date: August 06, 2015 04:54PM
Diagnosis Gotchas
Change Date: August 06, 2015 04:54PM
Diagnosis Gotchas
I just wanted to document a couple of gotchas for those who work on their Porsches. These two are off the top of my head, I'm going to go back through my maintenance records and see what else I can remember. Anyone else have any gotchas they can contribute?
Note: These were discovered with my MY99 986.
[list=1]
[*] If one of your oxygen sensors is shorted, short circuit codes for all four sensors will be thrown. You have to find the short by manually inspecting the wiring for all four sensors.
[*] You may not receive any code/CEL when your crankshaft position sensor fails. While troubleshooting a no start issue (engine cranked but didn't start, as if out of fuel) I tested my CKP sensor with a multimeter and discovered values totally out of spec. You'd think that a sensor which fails an electrical test so badly would trigger a CEL. Nope. Sensor is replaced now and it runs like a charm.
[/list]
Note: These were discovered with my MY99 986.
[list=1]
[*] If one of your oxygen sensors is shorted, short circuit codes for all four sensors will be thrown. You have to find the short by manually inspecting the wiring for all four sensors.
[*] You may not receive any code/CEL when your crankshaft position sensor fails. While troubleshooting a no start issue (engine cranked but didn't start, as if out of fuel) I tested my CKP sensor with a multimeter and discovered values totally out of spec. You'd think that a sensor which fails an electrical test so badly would trigger a CEL. Nope. Sensor is replaced now and it runs like a charm.
[/list]
Original Message
Author: Jayusa123Date: August 06, 2015 04:52PM
Diagnosis Gotchas
I just wanted to document a couple of gotchas for those who work on their Porsches. These two are off the top of my head, I'm going to go back through my maintenance records and see what else I can remember. Anyone else have any gotchas they can contribute?
[list=1]
[*] If one of your oxygen sensors is shorted, short circuit codes for all four sensors will be thrown. You have to find the short by manually inspecting the wiring for all four sensors.
[*] You may not receive any code/CEL when your crankshaft position sensor fails. While troubleshooting a no start issue (engine cranked but didn't start, as if out of fuel) I tested my CKP sensor with a multimeter and discovered values totally out of spec. You'd think that a sensor which fails an electrical test so badly would trigger a CEL. Nope. Sensor is replaced now and it runs like a charm.
[/list]
[list=1]
[*] If one of your oxygen sensors is shorted, short circuit codes for all four sensors will be thrown. You have to find the short by manually inspecting the wiring for all four sensors.
[*] You may not receive any code/CEL when your crankshaft position sensor fails. While troubleshooting a no start issue (engine cranked but didn't start, as if out of fuel) I tested my CKP sensor with a multimeter and discovered values totally out of spec. You'd think that a sensor which fails an electrical test so badly would trigger a CEL. Nope. Sensor is replaced now and it runs like a charm.
[/list]