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Fuel Pump Relay ( No 12v to Coil)

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

THIS DISCUSSION / SOURCE-DERIVED OVERVIEW

Discussion summary

YOUR RESEARCHFuel Pump Relay ( No 12v to Coil)

Leading reported evidence

Test relay

Performed · outcome unconfirmed

No successful repair reported for this finding.

0
Reported fixes: 0
Unsuccessful attempts: 1
Discussions

Read evidence and context

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 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
I have tested the relay which is OK, but i'm not getting any voltage to the coil.
Original post Read captured discussion
Fuel Pump Relay ( No 12v to Coil)

Performed · outcome unconfirmed
I have tested the relay which is OK, but i'm not getting any voltage to the coil.
Original post Read captured discussion
Fuel Pump Relay ( No 12v to Coil)

Frequently discussed work

Check cps (bridge fuel pump relay and start car*)

No successful repair reported for this finding.

0
Reported fixes: 0
Unsuccessful attempts: 1
Discussions

Read evidence and context

Discussions that contain suggestions: 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.

Suggestion
Won't hurt to check the CPS (bridge fuel pump relay and start car*) but OP is missing 12V at terminal 86 of the relay, which should be there as soon the ignition has been turned on irrespective of the crank turning or not.
Original post Read captured discussion
Fuel Pump Relay ( No 12v to Coil)

Read full discussion summary

Leading evidence: 'Test relay' (no explicit attributable resolution; this is a reported action or suggestion). Across 1 matching discussions, The most frequently discussed action is 'Check cps (bridge fuel pump relay and start car*)' (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.

Source reports, not a diagnosis or a success probability. Counts refer to discussions and can overlap.

Read captured replies

1 matching discussions · 4 captured posts examined · 0 partial discussions

Compare 3 other evidence results

Check cps (bridge fuel pump relay and start car*)

Suggestion or failed attempt

No successful repair reported for this finding.

0
Reported fixes: 0
Unsuccessful attempts: 1
Discussions

Read evidence and context

Discussions that contain suggestions: 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.

Suggestion
Won't hurt to check the CPS (bridge fuel pump relay and start car*) but OP is missing 12V at terminal 86 of the relay, which should be there as soon the ignition has been turned on irrespective of the crank turning or not.
Original post Read captured discussion
Fuel Pump Relay ( No 12v to Coil)

Check crankshaft position sensor

Suggestion or failed attempt

No successful repair reported for this finding.

0
Reported fixes: 0
Unsuccessful attempts: 1
Discussions

Read evidence and context

Discussions that contain suggestions: 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.

Suggestion
Check the crankshaft position sensor.
Original post Read captured discussion
Fuel Pump Relay ( No 12v to Coil)

Test crankshaft position sensor

Suggestion or failed attempt

No successful repair reported for this finding.

0
Reported fixes: 0
Unsuccessful attempts: 1
Discussions

Read evidence and context

Discussions that contain suggestions: 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.

Suggestion
This is a test for the crankshaft position sensor.
Original post Read captured discussion
Fuel Pump Relay ( No 12v to Coil)

Frequently discussed actions (4)

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

Check cps (bridge fuel pump relay and start car*)

No successful repair reported for this finding.

0
Reported fixes: 0
Unsuccessful attempts: 1
Discussions

Read evidence and context

Discussions that contain suggestions: 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.

Suggestion
Won't hurt to check the CPS (bridge fuel pump relay and start car*) but OP is missing 12V at terminal 86 of the relay, which should be there as soon the ignition has been turned on irrespective of the crank turning or not.
Original post Read captured discussion
Fuel Pump Relay ( No 12v to Coil)

Check crankshaft position sensor

No successful repair reported for this finding.

0
Reported fixes: 0
Unsuccessful attempts: 1
Discussions

Read evidence and context

Discussions that contain suggestions: 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.

Suggestion
Check the crankshaft position sensor.
Original post Read captured discussion
Fuel Pump Relay ( No 12v to Coil)

Test crankshaft position sensor

No successful repair reported for this finding.

0
Reported fixes: 0
Unsuccessful attempts: 1
Discussions

Read evidence and context

Discussions that contain suggestions: 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.

Suggestion
This is a test for the crankshaft position sensor.
Original post Read captured discussion
Fuel Pump Relay ( No 12v to Coil)

Test relay

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
I have tested the relay which is OK, but i'm not getting any voltage to the coil.
Original post Read captured discussion
Fuel Pump Relay ( No 12v to Coil)

Performed · outcome unconfirmed
I have tested the relay which is OK, but i'm not getting any voltage to the coil.
Original post Read captured discussion
Fuel Pump Relay ( No 12v to Coil)

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.

4 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: 20261027T084359Z · outcome-qualification-6. Deterministic extraction; no AI model inference. How we use sources

POST 1 / ORIGINAL POSTEROriginal post

I have an issue with my 996.1 Fuel pump / relay The pump runs when the relay is removed and the contacts are bridged - but other wise there is no life. I have tested the relay which is OK, but i'm not getting any voltage to the coil. Not had any issues with it before, drove out and parked up. 20 mins later it wouldn't start. Any ideas or assistance tracing the fault would be very much appreciated. Its a GT3 but i don't think that makes any difference and so have posted ion here in the hope it will have more visibility! TIA.

POST 2Original post

Check the crankshaft position sensor. If it fails the ECPU does not know that the engine is turning over and will not activate the fuel pump. When cranking the car does the tach needle bounce? This is a test for the crankshaft position sensor. If it is good the tach needle should bounce when cranking the engine. Hope this helps.

POST 3Original post

Won't hurt to check the CPS (bridge fuel pump relay and start car*) but OP is missing 12V at terminal 86 of the relay, which should be there as soon the ignition has been turned on irrespective of the crank turning or not. Once the crank turns and the ECU sees the CPS signal it switches terminal 85 of the relay to ground upon which it closes and the fuel pump starts running. *if engine starts your CPS is good. If it doesn't then the ECU probably doesn't receive a CPS signal and doesn't fire the coils or injectors. Check out post #28: no start It has a wiring diagram and further hints.

POST 4Original post

[QUOTE=M1ke77;19046352]I have an issue with my 996.1 Fuel pump / relay The pump runs when the relay is removed and the contacts are bridged - but other wise there is no life. I have tested the relay which is OK, but i'm not getting any voltage to the coil. Not had any issues with it before, drove out and parked up. 20 mins later it wouldn't start. Any ideas or assistance tracing the fault would be very much appreciated. Its a GT3 but i don't think that makes any difference and so have posted ion here in the hope it will have more visibility! the fuel pump relay gets 12 volts from the main relay (MFI ) and the main relay gets power through C1 fuse.

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