Fuel Gauge Appears Inaccurate or Inoperative for GMC Truck GMC P62 Commercial Chassis 1997
Fuel Gauge Appears Inaccurate or Inoperative P72
Step | Action | Value(s) | Yes | No |
|---|---|---|---|---|
1 | Does the fuel gauge read accurately? | -- | System OK | Go to Step 2 |
2 | Does the fuel gauge indicate empty when there is fuel in the tank? | -- | Go to Step 15 | Go to Step 3 |
3 | Does the fuel gauge indicate full (or beyond full) at all times? | -- | Go to Step 10 | Go to Step 4 |
4 |
Does the fuel gauge indicate empty and full? (Allow time for the gauge to reach full, due to the antislosh device.) | 0 ohms (empty) 900 ohms (full) | Go to Step 5 | Go to Step 7 |
5 | Check the BLK (150) wire for high resistance. Is the resistance at the specified value? | Greater than 90 ohms | Go to Step 6 | Go to Step 16 |
6 | Replace the fuel pump. Is the repair complete? | -- | Go to Step 1 | -- |
7 | Does the fuel gauge indicate empty? | -- | Go to Step 8 | Go to Step 3 |
8 | Check for high resistance in the PPL (30) wire. Is the resistance at the specified value? | Greater than 90 ohms | Go to Step 9 | Go to Step 16 |
9 | Replace the fuel gauge. Is the repair complete? | -- | Go to Step 1 | -- |
10 |
Does the fuel gauge indicate empty? | -- | Go to Step 11 | Go to Step 13 |
11 | Connect a fused jumper from the PPL (30) wire to the BLK (150) wire at the fuel pump and the sender connector. Does the fuel gauge indicate empty? | -- | Go to Step 12 | Go to Step 14 |
12 | Replace the fuel pump. Is the repair complete? | -- | Go to Step 1 | -- |
13 | Locate an open in the PPL (30) wire between the fuel pump, the sender connector and the fuel gauge. Is the PPL (30) wire open? | -- | Go to Step 16 | Go to Step 9 |
14 | Locate an open in the BLK (150) wire between the fuel pump, the sender connector and ground G400. Is the BLK (150) wire open? | -- | Go to Step 16 | -- |
15 |
Does the fuel gauge indicate full? | -- | Go to Step 6 | Go to Step 13 |
16 | Repair or replace the wire. Is the repair complete? | -- | Go to Step 1 | -- |
Fuel Gauge Appears Inaccurate or Inoperative P92
Step | Action | Value(s) | Yes | No |
|---|---|---|---|---|
1 | Does the fuel gauge read accurately? | -- | System OK | Go to Step 2 |
2 | Does the fuel gauge indicate empty when there is fuel in the tank? | -- | Go to Step 14 | Go to Step 3 |
3 | Does the fuel gauge indicate full (or beyond full) at all times? | -- | Go to Step 10 | Go to Step 4 |
4 |
Set the resistance dials. Does the fuel gauge indicate empty and full? (Allow time for gauge to reach full due to antislosh device.) | 0 ohms (empty) 90 ohms (full) | Go to Step 5 | Go to Step 7 |
5 | Check the WHT (14) wire for high resistance. Is the resistance at the specified value? | >90 ohms | Go to Step 6 | |
6 | Replace the fuel pump. Is the repair complete? | -- | Go to Step 11 | -- |
7 | Does the fuel gauge indicate empty? | -- | Go to Step 8 | Go to Step 3 |
8 | Check for high resistance in the WHR (16) wire. Is the resistance at the specified value? | >90 ohms | Go to Step 9 | Go to Step 15 |
9 | Replace the fuel gauge. Is the repair complete? | -- | Go to Step 1 | -- |
10 |
Does the fuel gauge indicate empty? | -- | Go to Step 11 | Go to Step 12 |
11 | Connect a fused jumper from the WHR (16) wire to the WHT (14) wire at the fuel pump and the sender connector. Does the fuel gauge indicate empty? | -- | Go to Step 6 | Go to Step 13 |
12 | Locate an open in the WHR (16) wire between the fuel pump, the sender connector, and the fuel gauge. Is the WHR (16) wire open? | -- | Go to Step 15 | Go to Step 9 |
13 | Locate the open in the WHT (14) wire between the fuel pump, the sender connector, and ground G400. Is the WHT (14) wire open? | -- | Go to Step 15 | -- |
14 |
Does the fuel gauge indicate full? | -- | Go to Step 6 | Go to Step 12 |
15 | Repair or replace the wire. Is the repair complete? | -- | Go to Step 1 | -- |
