Diagnostic Aids
WARNING: This page is about a different car, the 2004 GMC Sierra and 2004 Chevrolet Silverado. However, it is still accessible from the selected car via links, so may be relevant.
- Use the Temperature vs Resistance table in order to test the FRT sensor at various temperature levels in order to evaluate the possibility of a skewed sensor. A skewed sensor could result in a driveability condition. If the engine has sat overnight, the FRT sensor and the IAT values should display within a few degrees.
- For an intermittent condition, refer to Intermittent Conditions .
DTC P0186
| Step | Action | Values | Yes | No |
|---|---|---|---|---|
| Schematic Reference: Engine Controls Schematics Connector End View Reference: Engine Controls Connector End Views |
||||
| 1 | Did you perform the Diagnostic System Check Alternative Fuels - Engine Controls? | - | Go to Step 2 | Go to Diagnostic System Check - Alternative Fuels (Engine Controls) |
| 2 |
IMPORTANT:
Other DTCs may set.
|
4.95 V | Go to Step 3 | Go to Step 7 |
| 3 |
|
0.02 V | Go to Step 8 | Go to Step 4 |
| 4 |
|
0.02 V | Go to Step 6 | Go to Step 5 |
| 5 | Test the signal circuit of the fuel tank temperature (FTT) sensor for an open circuit or for high resistance. Refer to
Circuit Testing
and
Wiring Repairs
in Wiring Systems in the C/K Pickup Service Manual. Did you find and correct the condition? |
- | Go to Step 12 | Go to Step 9 |
| 6 | Test the low reference circuit of the FTT sensor for an open circuit or for high resistance. Refer to
Circuit Testing
and
Wiring Repairs
in Wiring Systems in the C/K Pickup Service Manual. Did you find and correct the condition? |
- | Go to Step 12 | Go to Step 9 |
| 7 | Test the signal circuit of the FTT sensor for a shorted to ground condition. Refer to
Circuit Testing
and
Wiring Repairs
in Wiring Systems in the C/K Pickup Service Manual. Did you find and correct the condition? |
- | Go to Step 12 | Go to Step 9 |
| 8 | Test for an intermittent and for a poor connection at the FTT sensor. Refer to
Circuit Testing
and
Wiring Repairs
in Wiring Systems in the C/K Pickup Service Manual. Did you find and correct the condition? |
- | Go to Step 12 | Go to Step 10 |
| 9 | Test for an intermittent and for a poor connection at the fuel injector control module (FICM). Refer to
Testing for Intermittent Conditions and Poor Connections
and
Connector Repairs
in Wiring Systems in the C/K Pickup Service Manual. Did you find and correct the condition? |
- | Go to Step 12 | Go to Step 11 |
| 10 | Replace the FRT sensor. Refer to Fuel Rail Temperature (FRT) Sensor Replacement
. Did you complete the replacement? |
- | Go to Step 12 | - |
| 11 | Replace the FICM. Refer to Fuel Injection Control Module Replacement
. Did you complete the replacement? |
- | Go to Step 12 | - |
| 12 |
|
- | Go to Step 2 | Go to Step 13 |
| 13 | Observe the Capture Info with a scan tool. Are there any DTCs that have not been diagnosed? |
- | Go to Diagnostic Trouble Code (DTC) List | System OK |