PCM power relay is chattering

10

Asked by Nov 03, 2016 at 12:48 PM about the 1999 Ford F-250 4 Dr Lariat Extended Cab SB

Question type: Maintenance & Repair

When the key is turned on ready to start the PCM relay chatters. The truck
will not start. OBD reader turns on runs through scan test but will not link up
sends back information to check various other  things that are working. I tried
another scanner with the same result. I have changed the CPS but noticed
the fuel pump is not coming on I have checked fuel interrupt on passenger
side. This is a 2002 super duty f250

8 Answers

94,925

Check the relays power and grounds feeds just too make sure the voltage is stable, if it is then replace the relay, I have seen this happen on the old MCU system but not on the OBD2 system, but anything is possible.

10

It's actually the relay below the PCM the injector drive relay I have switched it with others and it still sounds like an electric fuel pump it is chattering so bad

1 of 1 people found this helpful.
94,925

Then you still need to find out if the relays supply voltage and grounds are stable, if the are then you either have a high amperage draw on the ECM power feed wire or a short in the ECM itself, and either of those would explane the OBD link failure and the no start and no fuel pump.

10

I put a jumper wire to the pump it comes on with the new power source but still will not fire

94,925

That is cause the ECM is not sending any signals out. Get out the wiring diagrams and start tracing circuits, I would start with the main power and ground feeds to the ECM, disconnect power and use an ohm meter to check continuity on the wiring.

10

thank you but I think that you just went beyond my skill level. I'm kind of a plug and play guy I can remove and install but doing electrical diagnostics is beyond my capability I guess it's time to take it to a shop Thank you for your help

10

What does the injector drive module do

10

i hooked a jumper wire to the silinode on top of the motor and was able to start the truck the buzzing in the relay quit the truck started so it has to be a fuse some ware in this system that is not closing the Circuit

Your Answer

Add photo

Related Questions

  • PCM power relay is chattering 8 answers

    When the key is turned on ready to start the PCM relay chatters. The truck will not start. OBD reader turns on runs through scan test but will not link up sends back information to check various oth...

    1999 Ford F-250 4 Dr Lariat Extended Cab SB

    -

    Maintenance & Repair

  • 1989 ford f-250 looses power to the fuel selector switch then no power to the fuel pumps ive replaced the fuel pump relay and it clicks in then drops off help 2 answers

    i loose power to the fuel pump selector swith and ive replaced the fuel pump relay when i turn on the ignition i have power to the pink black wire on the fuel tank switch then i loose power to it an...

    1989 Ford F-250 XLT Lariat Standard Cab LB

    -

    Maintenance & Repair

  • Can i put power steering in my 1977 F250? 2 answers

    My thruck is a 77 F250 with a 300 inline 6 is there any way to install power steering in it?

    1977 Ford F-250

    -

    Maintenance & Repair

  • The OD light is flashing.. 1 answer

    When trying to accelerate a weird putting noise and loss of power occurs, which causes the OD to start flashing.. what could this be?

    Ford F-250

    -

    Maintenance & Repair

  • Power to cab 6 answers

    I can't get power to cab unless I hotwire from battery to ignition coil.but once I do my dash lights turn signals and dome lights don't work. Head lights and break lights work... Why

    1987 Ford F-250

    -

    Maintenance & Repair

F-250

Looking for a Used F-250 in your area?

CarGurus has 469 nationwide F-250 listings starting at $2,000.

ZIP:

Search Ford F-250 Questions

Ford F-250 Experts

#1 tennisshoes
tennisshoes
Reputation 620
#2 dandyoun
dandyoun
Reputation 350
#3 F_O_R
F_O_R
Reputation 320
View All

Related Models For Sale

Used Ford F-250 Super Duty
330 Great Deals out of 46,264 listings starting at $1,450
Used Ford F-150
2,059 Great Deals out of 207,350 listings starting at $1,499
Used Dodge Ram 2500
143 Great Deals out of 5,158 listings starting at $1,499
Used Ford F-350 Super Duty
373 Great Deals out of 25,770 listings starting at $1,995
Used Chevrolet Silverado 1500
1,772 Great Deals out of 181,204 listings starting at $250
Used Chevrolet Silverado 2500
5 Great Deals out of 245 listings starting at $4,900
Used Dodge Ram 1500
412 Great Deals out of 10,832 listings starting at $1,400
Used Toyota Tundra
438 Great Deals out of 34,679 listings starting at $2,990
Used GMC Sierra 1500
761 Great Deals out of 69,133 listings starting at $1,850
Used Ford Mustang
537 Great Deals out of 45,845 listings starting at $1,999
Used GMC Sierra 2500
151 listings starting at $4,500

Used Cars For Sale

Content submitted by Users is not endorsed by CarGurus, does not express the opinions of CarGurus, and should not be considered reviewed, screened, or approved by CarGurus. Please refer to CarGurus Terms of Use.