The message to which you are about to reply is shown first. GO TO REPLY FORM



 VIEW    REPLY TO THIS MESSAGE Replies to this message will be emailed.    PRINT   SAVE 

84 244DL - No Power To The Pumps (NOT just a relay problem!) 200 1984

posted by  ntaylor512 on  Fri Jul 26 14:30 CST 2002
Author: [PROFILE] [EVERY POST] [THREADS] [BEST POSTS] RSS Feed     [IGNORE ALL POSTS] [RELATED]

Ok.. Im a bit lost here now, something just doesnt seem right. i was really hoping the relay just died, but not the case... relay is just fine and dandy.

Car died on the road. No power to the pumps. Towed home (first time a volvo has ever left me stranded) - tried usual tricks (shorting out the relay to get the pump going) but no avail.

Start from the beginning... main system relay is kicking in.. power is getting to the LH2.0 ECU from both the system relay (ecu pin 9 + ground w/ 21 grounded) and from the ign switch (ecu pin 18 + ground). both ground pins of the ECU have a good ground. +vdc power to the primary side of the fuel pump relay (relay term 30), as well as the positive side of the coil (term 86). power on the other side of the relay coil (through the coil, on pin 85) ... removed relay... pin 85 (connects to ECU term #21) is supposed to get grounded when the engine starts cranking (to turn the fuel pump on) - it is infact not being grounded by the ECU, and this is the start of the problem. Remove ECU connector, replace fuel pump relay... manually ground pin 17 w/ ignition on and the fuel pump starts up.

so, why would the ECU not be grounded pin 17? The bentley book says causes could be a faulty ECU or no engine RPM signal...

so... i happen to have a spare ECU on hand for this car that i know is good.. tried it. no luck there.

figure maybe it's the RPM signal .. so again.. i delve back into checking voltages... pin 1 is the RPM signal, pin 4 is the cranking signal.. i get about battery voltage at both terminals when the engine is being turned with the starter and dead when the engine is not being turned

i thought maybe it was a wiring thing, something not getting power.. i checked the wiring runs in question and they've all showed end-to-end continuity.

another important note: there is some other problem. i grounded term 85 manually on the relay to start the pumps... and tried to start the car. no go.

checked:
ECU power from relay & ignition (pins 9 and 18)
engine RPM and cranking signal (pins 1 and 4)
ECU grounds (11 and 25)
term 17 - ground it and the pumps start right up

what am i missing... ??? the ecu is getting something right and im not sure what it is... i mean, turning on the fuel pump shouldnt require THAT much input to the system...

thanks for any suggestions! i'm probably missing something OBVIOUS here.

-nate





USERNAME
Use "claim to be" below if you don't want to log in.
PASSWORD
I don't have an account. Sign me up.
CLAIM TO BE
Use only if you don't want to login (post anonymously).
ENTER CAPTCHA CODE
This is required for posting anonymously.
OPTIONS notify by email
Available only to user accounts.
SUBJECT
MODEL/YEAR
MESSAGE

DICTIONARY
LABEL(S) +
IMAGE URL *
[IMAGE LIBRARY (UPLOAD/SELECT)]

* = Field is optional.

+ = Enter space delimited labels for this post. An example entry: 240 muffler


©Jarrod Stenberg 1997-2022. All material except where indicated.


All participants agree to these terms.

Brickboard.com is not affiliated with nor sponsored by AB Volvo, Volvo Car Corporation, Volvo Cars of North America, Inc. or Ford Motor Company. Brickboard.com is a Volvo owner/enthusiast site, similar to a club, and does not intend to pose as an official Volvo site. The official Volvo site can be found here.