DTC P0168 (LPL or LPV)
Diagnostic Instructions
DTC Descriptor
| DTC P0168 00: Engine Fuel Overtemperature |
Circuit/System Description
The engine control module (ECM) measure the fuel temperature.
The fuel temperature is used to calculate the fuel quantity or to
enable an engine protection mode.
Conditions for Running the DTC
| • |
The engine speed is greater
than 1 000 RPM. |
Conditions for Setting the DTC
The ECM detects the fuel temperature is higher than a
threshold.
Action Taken When the DTC Sets
DTC P0168 00 is a Type B DTC.
Conditions for Clearing the DTC
DTC P0168 00 is a Type B DTC.
Diagnostic Aids
| • |
Test the fuel temperature
sensor at various temperature levels in order to evaluate the
possibility of a skewed sensor. A skewed sensor can result in a DTC
or a driveability condition. Refer to
Temperature Versus Resistance . |
| • |
A resistance condition in the
fuel temperature sensor circuits may cause this DTC. This condition
results in a greater voltage on the fuel temperature sensor signal
circuit, which is interpreted by the ECM as a colder fuel
temperature. |
Reference Information
Schematic Reference
Engine Controls Schematics
Connector End View Reference
Component Connector End Views
Electrical Information Reference
Scan Tool Reference
Control Module References for scan tool information
Circuit/System Verification
| 1. |
Engine running for 60 s.
Observe the DTC information with a scan tool. DTC P0168 should not
set. |
| 2. |
Operate the vehicle within the
Conditions for Running the DTC to verify the DTC does not reset.
You may also operate the vehicle within the conditions that you
observed from the Freeze Frame/Failure Records data. |
Circuit/System Testing
| 1. |
Ignition OFF, disconnect the
harness connector at the B48 Fuel Temperature Sensor. |
| 2. |
Test for less than 5 Ω
between the low reference circuit terminal 3 and ground.
|
| ⇒ |
If greater than the specified range, test the low
reference circuit for an open/high resistance. If the circuit tests
normal, replace the K20 Engine Control Module. |
| 3. |
Ignition ON, verify the scan
tool Fuel Temperature Sensor 1 is at -30°C (-22°F).
|
| ⇒ |
If greater than the specified range, test the
signal circuit terminal 1 for a short to ground. If the circuit
tests normal, replace the K20 Engine Control Module. |
|
Note: If the fuse in
the jumper wire opens, the signal circuit is shorted to a voltage
and the sensor may be damaged.
|
| 4. |
Ignition ON, connect a 3 A
fused jumper wire between the signal circuit terminal 1 and ground.
Verify the scan tool Fuel Temperature Sensor 1 parameter is greater
than 110°C (230°F). |
| ⇒ |
If less than the specified range, test the signal
circuit for a short to voltage or an open/high resistance. If the
circuit tests normal, replace the K20 Engine Control Module. |
| 5. |
If all circuits test normal,
test or replace the B48 Fuel Temperature Sensor. |
Repair Instructions
Perform the
Diagnostic Repair Verification after completing the diagnostic
procedure.
|
