DTC P1263 Without RPO CTF
Circuit Description
A hydraulic piston and two-way valve (TWV) or solenoid valve have been added to the conventional nozzle. Receiving signals from the engine control module (ECM), the TWV opens and closes to change the pressure in the pressure adjustment chamber on top of the hydraulic piston so that the hydraulic piston operates, thereby ejecting the fuel from the nozzle. If the ECM detects a low voltage condition on the TWV voltage supply circuit of cylinder 1, 2 or 3, DTC P1263 will set. If the ECM detects a high voltage condition on the TWV voltage supply circuit of cylinder 1, 2 or 3, DTC P1264 will set.
Conditions for Running the DTC
| • | Battery voltage is more than 10 volts. |
| • | There is no engine overspeed condition. |
Conditions for Setting the DTC
The TWV voltage supply circuit is shorted to ground.
Action Taken When the DTC Sets
| • | The control module illuminates the malfunction indicator lamp (MIL) when the diagnostic runs and fails. |
| • | The ECM limits fuel delivery on cylinders 4, 5, and 6. The ECM stop fuel injection on cylinders 1, 2, and 3. |
Conditions for Clearing the MIL/DTC
| • | The control module turns OFF the malfunction indicator lamp (MIL) after 3 consecutive ignition cycles that the diagnostic runs and does not fail. |
| • | A current DTC, Last Test Failed, clears when the diagnostic runs and passes. |
| • | Clear the MIL and the DTC with a scan tool. |
Diagnostic Aids
Inspect for the following conditions:
| • | Poor connection at the ECM |
| Inspect the harness connectors for backed-out terminals, improper mating, broken locks, improperly formed or damaged terminals, and poor terminal-to-wire connection. |
| • | Erratic RPM |
| • | Lack of engine power |
Step | Action | Value | Yes | No | ||||||
|---|---|---|---|---|---|---|---|---|---|---|
Schematic Reference: Engine Controls Schematics | ||||||||||
1 | Does the scan tool display the DTC while the ignition is ON or the engine is running? | -- | Go to Step 2 | Go to Intermittent Conditions | ||||||
2 |
Does each resistance measure more than the specified value? | 10 M ohms | Go to Step 3 | Go to Step 4 | ||||||
3 | Measure resistance following points at the ECM connector on the TWV harness:
Does the resistance measure more than the specified value? | 10 M ohms | Go to Step 5 | Go to Step 4 | ||||||
4 | Repair/replace the TWV harness. Did you complete the action? | -- | Go to Step 5 | -- | ||||||
5 |
Does the DTC reset? | -- | Go to Step 6 | Go to Step 8 | ||||||
6 | Replace the ECM. Did you complete the replacement? | -- | Go to Step 7 | -- | ||||||
7 |
Does the DTC reset? | -- | Go to Step 2 | Go to Step 8 | ||||||
8 | Did any other DTCs set? | -- | System OK | |||||||
