operatorfailure

iTrader: (3)

I have put a 5.3/4l60 into my 68 c-10, for a fuel system I am running an 01 camaro fuel pump/sender assembly in a fuel cell and can't seem to figure out how to get the gauge to work. I also have a cluster out of the same car, but that is a complete other problem. I basically just want to get it where I can see my fuel level in hptuners and through the Torque app on my phone right now. I have the wiring diagram but I can't make heads or tails of it. The pump works fine, the truck drives great, it's just the sending unit I can't get working.



That is the diagram, I added the wonderful paintbrush squares with numbers to make it easier. What makes sense to me is #1 power, #2, 3 and 4 ground, #5 to red connector pin 54, #6 to a switched +5v feed, #7 to red connector pin 64. That is how I have it wired up, and no luck.

When I have it wired like this I am getting a constant +5v out of #3 and 4 ground wires, which makes no sense to me.

What am I doing wrong?

62n62

iTrader: (17)

Fuel Gauge Inaccurate or Inoperative
Diagnostic Aids•Ensure that the fuel level is in the same range as the customer concern.
•For intermittent diagnosis, refer to Testing for Intermittent Conditions and Poor Connections in Wiring Systems.
•Refer to Fuel Level Specifications in order to verify the correct fuel level sender readings. The Fuel Tank Level Remaining parameter is available on the scan tool in the PCM EVAP data list.
Test DescriptionThe numbers below refer to the step numbers in the diagnostic table.

3.This step tests for a high resistance in the signal circuit and the sensor ground circuit of the fuel level sender.
13.DTCs will set in the PCM when you perform this diagnostic table.
Fuel Gauge Inaccurate or Inoperative Step
Action
Value(s)
Yes
No

Schematic Reference: Instrument Cluster Schematics

1
Did you perform the IPC Diagnostic System Check?
—
Go to Step 2
Go to Diagnostic System Check - Instrument Cluster

2
 1. Disconnect C405A/C405B.
 2. Connect the J 33431-C Signal Generator and Instrument Panel Tester between the signal circuit of the fuel level sensor and the sensor ground circuit of the fuel level sensor at the male terminal side.
 3. Turn on the ignition, with the engine off.
Important: Verify the J 33431-C resistance settings with a DMM.

 4. Vary the resistance on the J 33431-C from 40–250 Ω. Refer to Fuel Level Specifications in order to convert from resistance to fuel gauge display.
Does the fuel gauge display the correct fuel level?
—
Go to Step 4
Go to Step 3

3
 1. Install a scan tool.
 2. Turn on the ignition, with the engine off.
Important: Verify the J 33431-C resistance settings with a DMM.

 3. Vary the resistance on the J 33431-C from 40–250 Ω. Refer to Fuel Level Specifications in order to convert from resistance to fuel level %.
Important: Turn OFF the ignition momentarily between the resistance settings in order to quickly update the scan tool display.

 4. With the scan tool, observe the Fuel Tank Level Remaining parameter in the PCM EVAP data list.
Does the scan tool display the correct fuel level %?
—
Go to Step 11
Go to Step 5

4
Inspect for the following items:

•A poor connection at the harness connector of the fuel level sensor
Refer to Testing for Intermittent Conditions and Poor Connections and to Connector Repairs in Wiring Systems.

•A high resistance in the signal circuit or the sensor ground circuit between the fuel level sensor and C405A/C405B
Refer to Circuit Testing and to Wiring Repairs in Wiring Systems.

•A misaligned fuel level sensor
•A deformed fuel tank
Did you find and correct the condition?
—
Go to Step 13
Go to Step 7

5
Test the signal circuit of the fuel level sensor for a high resistance. Refer to Circuit Testing and to Wiring Repairs in Wiring Systems.

Did you find and correct the condition?
—
Go to Step 13
Go to Step 6

6
Test the sensor ground circuit of the fuel level sensor for a high resistance. Refer to Circuit Testing and to Wiring Repairs in Wiring Systems.

Did you find and correct the condition?
—
Go to Step 13
Go to Step 9

7
 1. Remove the fuel level sensor.
 2. Inspect for the following items:
◦A stuck fuel level sensor, i.e. the fuel strainer interfering with the sensor float arm
◦Foreign material in the gas tank, i.e. ice
Did you find and correct the condition?
—
Go to Step 13
Go to Step 8

8
 1. With the J 39200 DMM, measure the resistance of the fuel level sensor while moving the float arm.
 2. Observe both the analog and digital displays on the DMM.
Does the resistance change smoothly across the specified range?
40–250 Ω
Go to Diagnostic Aids
Go to Step 10

9
Inspect for poor connections at the harness connector of the PCM. Refer to Testing for Intermittent Conditions and Poor Connections and to Connector Repairs in Wiring Systems.

Did you find and correct the condition?
—
Go to Step 13
Go to Step 12

10
Replace the fuel level sensor. Refer to Fuel Level Sensor Replacement in Engine Controls-3.8L or to Fuel Level Sensor Replacement in Engine Controls-5.7L.

Did you complete the replacement?
—
Go to Step 13
—

11
Important: Program the replacement IPC.

Replace the IPC. Refer to Instrument Cluster Replacement.

Did you complete the replacement?
—
Go to Step 13
—

12
Important: Program the replacement PCM.

Replace the PCM. Refer to Powertrain Control Module Replacement in Engine Controls-3.8L or to Powertrain Control Module Replacement in Engine Controls-5.7L.

Did you complete the replacement?
—
Go to Step 13
—

13
 1. Use a scan tool in order to clear the PCM DTCs.
 2. Operate the system in order to verify the repair.
Did you correct the condition?
—
System OK
Go to Step 2

62n62

iTrader: (17)

with tank unit unpluged are 2 and 3 grounded checking with a test light to 12 volts

operatorfailure

iTrader: (3)

With tank unplugged, yes, 2 and 3 are grounded. I don't have them ran to the pcm, just grounded to the frame.

62n62

iTrader: (17)

grounds and the 5 volts have to come from pcm/ecm

operatorfailure

iTrader: (3)

I had the 5v from the pcm, so I went out and wired up the grounds through the pcm. No change. I got out my cheap little analog multimeter (and I don't really know how to use it) and was seeing 40 ohms resistance with it on the highest setting, and from what I understand that is what it is supposed to show when empty, but my tank isn't empty. Possibly bad sending unit?

Ollie8974

The Fuel level system in the 68 C10 is incompatible with the Camaro fuel pump module. The 68 C10 system operates on 0 to 90 ohms. The 01 fuel level sender operates on 40 to 240 ohms.
GM PN 25319676 ACD#SK1083
is the fuel level sender part number for a 0 to 90 ohm fuel level sender for the 01 Camaro fuel pump module.

operatorfailure

iTrader: (3)

I am using the complete fuel pump/sender/bucket assembly out of the camaro.

operatorfailure

iTrader: (3)

Ended up getting it to work, 62n62 was right, the second time I ran the grounds from the pcm it worked. (I'm guessing I had something crossed the first time)

Thanks!

southerntidefan

Which pins did you go back to? I have same issue

southerntidefan

Do you have to wire in the pressure sensor or is it OK to just do the pump/sender. My pump works but sender won't read in torque.

operatorfailure

iTrader: (3)

I ended up wiring in the pressure sensor and it worked after that. I'm not sure if it was totally necessary but once it started working I didn't change anything.

operatorfailure

iTrader: (3)

I think it was pin 53 and 80 on the blue connector.