Circuit Description
A microprocessor in the instrument cluster sends voltage to the fuel tank sensor contained inside the fuel tank. A float arm attached to the sensor changes position with the fuel level in the tank. The fuel sensor is a variable resistor, as the fuel level changes the resistance of the fuel sensor changes. The instrument cluster monitors changes in the voltage caused by the changes in the resistance of the sensor to determine fuel level.
Conditions for Setting the DTC
The fuel gauge circuit is tested every 100 ms. DTC 167 will set in the following ways:
| • | When the circuit is shorted to ground. |
| • | The resistance of the fuel sensor is out of range (less than 30 ohms) for more than 8 seconds. |
Action Taken When the DTC Sets
| • | Stores a DTC 167 in memory. |
| • | The fuel gauge pointer will return to the zero position. |
Conditions for Clearing the MIL/DTC
| • | The resistance must be greater than 30 ohms for 4 seconds to clear the fault in the next monitoring cycle. |
| • | Conditions for the fault are no longer present. |
| • | Using a scan tool. |
Diagnostic Aids
| • | If the DTC is a history or intermittent DTC try performing the tests shown while WIGGLING wiring and connectors. This can often cause the malfunction to appear. |
| • | Visually inspect the harness and the harness connectors for the following conditions: |
| • | Damage |
| • | Corrosion |
| • | Water intrusion |
| • | Adequate terminal tension |
| • | Mis-routed harness |
| • | Rubbed through wire insulation |
| • | Broken wire inside the insulation |
| • | Before replacing the instrument cluster check all power and ground circuits to the cluster. |
Test Description
The number(s) below refer to the step number(s) on the diagnostic table.
-
This test determines if the fuel tank sensor is shorted.
-
This test determines if system voltage is present. No voltage may indicate that a short to ground exists in the circuit.
-
All the components need to be removed from the circuit to obtain an accurate reading.
-
After a circuit repair is made. The instrument cluster is checked again to see if the DTC resets indicating an internal failure.
Step | Action | Value(s) | Yes | No |
|---|---|---|---|---|
1 | Was the Instrument Cluster System Check performed? | -- | Go to Instrument Cluster System Check | |
2 |
Is the resistance reading 30 ohms or less? | -- | ||
3 | Replace the fuel tank sensor. Refer to Fuel Controls. Is the replacement complete? | -- | -- | |
4 |
Is the voltage within the specified range? | B+ | ||
5 | Move related harnesses and harness connectors while monitoring the DMM. Was a circuit problem found and repaired? | -- | Go to Instrument Cluster System Check | |
6 |
Is the voltage reading within the specified range? | B+ | ||
7 |
Is a current DTC 167 set? | -- | Go to Instrument Cluster System Check | |
8 | Repair the short to ground between C200A terminal 2 and C400 terminal C (CKT PF12). Is the repair complete? | -- | -- | |
9 |
Is the resistance within the specified range? | OL | ||
10 | Replace and program the instrument cluster. Is the replacement complete? | -- | Go to Instrument Cluster System Check | -- |
11 | Locate and repair the short to ground in CKT PF1 or the circuit that leads to terminal 73 of the ECM. Refer to Engine Controls in Cell 20 for further details on the ECM circuit. Is the repair complete? | -- | -- |
