• | Verify 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 . |
• | Use the fuel sender resistance (0-90 ohms) to verify the fuel level sender operation. When the fuel tank is empty, the sender resistance is 0 ohms. When the fuel tank is full, the sender resistance is 90 ohms. |
The number below refers to the step number on the diagnostic table.
Step | Action | Value(s) | Yes | No | ||||||
---|---|---|---|---|---|---|---|---|---|---|
Schematic Reference: Instrument Cluster Schematics | ||||||||||
1 | Did you review the system operation and perform the necessary inspections? | -- | Go to Step 2 | |||||||
Important: Verify the J 33431-C resistance settings with a DMM. Does the fuel gage move from empty to full? | -- | Go to Step 3 | Go to Step 4 | |||||||
3 | Inspect for the following items:
Did you find and correct the condition? | -- | Go to Step 11 | Go to Step 6 | ||||||
4 | Test the signal circuit of the fuel level sender for an open, for a short to ground or for a high resistance between the fuel level sender and the IPC. Refer to Circuit Testing and to Wiring Repairs in Wiring Systems. Did you find and correct the condition? | -- | Go to Step 11 | Go to Step 5 | ||||||
5 | Test the fuel sender ground circuit for an open or 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 11 | Go to Step 8 | ||||||
6 |
Did you find and correct the condition? | Go to Step 11 | Go to Step 7 | |||||||
7 |
Does the resistance change smoothly across the specified range? | 0-90 ohms | Go to Diagnostic Aids | Go to Step 9 | ||||||
8 | Inspect for poor connections at the harness connector of the IPC. 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 11 | Go to Step 10 | ||||||
9 | Replace the fuel level sender. Refer to Duramax® Medium Duty Diesel Engine Manual. Did you complete the replacement? | -- | Go to Step 11 | -- | ||||||
10 | Replace the IPC. Refer to Instrument Cluster Replacement . Did you complete the replacement? | -- | Go to Step 11 | -- | ||||||
11 | Operate the system in order to verify the repair. Did you correct the condition? | -- | System OK | Go to Step 2 |
• | Verify 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 . |
• | Use the fuel level sender resistance (0-90 ohms) to verify the fuel level sender operation. When the fuel tank is empty, the fuel level sender resistance is 0 ohms. When the fuel tank is full, the fuel level sender resistance is 90 ohms. |
The numbers below refer to the step numbers on the diagnostic table.
This step tests for a malfunction in the fuel level sender.
This step tests for a malfunction in the fuel level sensor signal circuit or the IPC.
Step | Action | Value(s) | Yes | No | ||||||
---|---|---|---|---|---|---|---|---|---|---|
Schematic Reference: Instrument Cluster Schematics | ||||||||||
1 | Did you review the system operation and perform the necessary inspections? | -- | Go to Step 2 | |||||||
Important: Verify the J 33431-C resistance settings with a DMM. Does the fuel gage move from approximately empty to approximately full? | -- | Go to Step 4 | Go to Step 3 | |||||||
Important: Verify the J 33431-C resistance settings with a DMM. Does the fuel gage move from approximately empty to approximately full? | -- | Go to Step 6 | Go to Step 5 | |||||||
4 | Inspect for the following items:
Did you find and correct the condition? | -- | Go to Step 16 | Go to Step 9 | ||||||
5 | Test the fuel level sender signal circuit for an open, for a short to ground or for a high resistance between the IPC and the fuel sender and transfer pump control module. Refer to Circuit Testing and to Wiring Repairs in Wiring Systems. Did you find and correct the condition? | -- | Go to Step 16 | Go to Step 8 | ||||||
6 | Test the signal circuits of the primary and the secondary fuel level senders for an open, for a short to ground or for a high resistance between the fuel level senders and the fuel sender and transfer pump control module. Refer to Circuit Testing and to Wiring Repairs in Wiring Systems. Did you find and correct the condition? | -- | Go to Step 16 | Go to Step 7 | ||||||
7 | Test the ground circuit of the fuel level senders for an open or 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 16 | Go to Step 11 | ||||||
8 | Test the ground circuit of the fuel sender and transfer pump control module for an open or 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 16 | Go to Step 12 | ||||||
9 |
Did you find and correct the condition? | -- | Go to Step 16 | Go to Step 10 | ||||||
10 |
Does the resistance change smoothly across the specified range for both fuel level senders? | 0-90 ohms | Go to Diagnostic Aids | Go to Step 13 | ||||||
11 | Inspect for poor connections at the harness connector of the fuel sender and transfer pump control module. 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 16 | Go to Step 15 | ||||||
12 | Inspect for poor connections at the harness connector of the IPC. 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 16 | Go to Step 14 | ||||||
13 | Replace the primary or the secondary fuel level sender that did not have the correct resistance values. Refer to the Duramax® 7800 Medium Duty Diesel Engine Manual. Did you complete the replacement? | -- | Go to Step 16 | -- | ||||||
14 | Replace the IPC. Refer to Instrument Cluster Replacement . Did you complete the replacement? | -- | Go to Step 16 | -- | ||||||
15 | Replace the fuel sender and transfer pump control module. Refer to the Duramax® 7800 Medium Duty Diesel Engine Manual. Did you complete the replacement? | -- | Go to Step 16 | -- | ||||||
16 | Operate the system in order to verify the repair. Did you correct the condition? | -- | System OK | Go to Step 2 |