WhalePirot
Well-known member
Circuit description
The fuel pump signal is monitored for voltage by the ECM and is used to compensate fuel delivery based on system voltage. This signal is also used to store a trouble code, if the relay is defective or fuel pump oltage is lost while the engine is running. There should be about 12vdc on CKT 458 (oil pressure switch output to FP1 (10amp fuse) for two seconds after ignition is turned on, or any time reference pulses are being received by the ECM.
Code 54 will set if teh voltage on 458 is less than 2vdc for 1.5 seconds since the last reference pulse. This code is designed to detect a faulty relay, causing extended crank time, and the code will help diagnosis of an engine that cranks, but will not run.
If a fault is etected during start, the SES light will stay on until the ignitionis cycled off. If the voltage is detected below 2vdc with the engine running, the light will only remain on while the condition exists. Hmmmmm, your 'flash'.
The fuel pump test connector (circuit 490) is located under the master cylinder, near the battery.
Depending on your flow through the troubleshooting chart for Code 54, it could be an open circuit from various components (or faulty components), namely, the the oil pressure sending {Pin1}unit, the ECM(circuit 465){Pin 5}, a bad relay or pump, or faulty ground {Pin2} to the components.
{refers to fuel pump relay pins}, as below with tab to the left.
2
[[ 1 3 4
5
= = =
It also suggests checking, with engine idling at normal temperature:
-oil press. normal
-disconnect pump relay
-engine continues to run.
No- faulty oil pressure switch (disconnected?)
Yes- recomnnect fuel pump relay
ignition off
check grounded test light on FP test terminall
Light- OFF ON
circuit ok faulty oil press. sw.
I hope you get it fixed. I have things to DO.
The fuel pump signal is monitored for voltage by the ECM and is used to compensate fuel delivery based on system voltage. This signal is also used to store a trouble code, if the relay is defective or fuel pump oltage is lost while the engine is running. There should be about 12vdc on CKT 458 (oil pressure switch output to FP1 (10amp fuse) for two seconds after ignition is turned on, or any time reference pulses are being received by the ECM.
Code 54 will set if teh voltage on 458 is less than 2vdc for 1.5 seconds since the last reference pulse. This code is designed to detect a faulty relay, causing extended crank time, and the code will help diagnosis of an engine that cranks, but will not run.
If a fault is etected during start, the SES light will stay on until the ignitionis cycled off. If the voltage is detected below 2vdc with the engine running, the light will only remain on while the condition exists. Hmmmmm, your 'flash'.
The fuel pump test connector (circuit 490) is located under the master cylinder, near the battery.
Depending on your flow through the troubleshooting chart for Code 54, it could be an open circuit from various components (or faulty components), namely, the the oil pressure sending {Pin1}unit, the ECM(circuit 465){Pin 5}, a bad relay or pump, or faulty ground {Pin2} to the components.
{refers to fuel pump relay pins}, as below with tab to the left.
2
[[ 1 3 4
5
= = =
It also suggests checking, with engine idling at normal temperature:
-oil press. normal
-disconnect pump relay
-engine continues to run.
No- faulty oil pressure switch (disconnected?)
Yes- recomnnect fuel pump relay
ignition off
check grounded test light on FP test terminall
Light- OFF ON
circuit ok faulty oil press. sw.
I hope you get it fixed. I have things to DO.
.
