Circuit Description
A hydraulic piston and the 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 to inject the fuel from the nozzle.
Conditions for Setting the DTC
| • | Common 1 |
| • | TWV driving system B+ shorted |
| TWV harness B+ shorted and/or common harness B+ shorted and battery voltage is higher than 10 volts except when an overspeed condition occurs. |
| • | TWV driving system ground shorted |
| TWV harness ground shorted and/or common harness ground shorted and battery voltage is higher than 10 volts except when an overspeed condition occurs. |
Action Taken When the DTC Sets
| • | The ECM will illuminate the malfunction indicator lamp (MIL) the first time the fault is detected. |
| • | The ECM sets the current control constant for the normal fuel rail and shuts down the abnormal fuel rail. |
| • | Constant current control by common 1 or common 2 circuit, whichever is normal. The abnormal system is separated. |
| • | Fuel injection volume is limited to a maximum 80 mm³/seconds and the ECM shuts off boost. |
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. |
| • | A history DTC clears after 40 consecutive warm-up cycles, if no failures are reported by this or any other emission related diagnostic. |
| • | Clear the MIL and the DTC with a scan tool. |
DTC 0159 can be cleared by using the Clear Info on the scan tool or by using the Diag Clear Switch.
Diagnostic Aids
Inspect for the following conditions:
| • | Poor connection at the ECM |
| Inspect 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 DTC 0158 or DTC 0159 set while the ignition is ON or the engine is running? | -- | Go to Step 2 | Go to Diagnostic Aids | ||||||||||||
2 |
Does each voltage measure less than the specified value? | 1 V | Go to Step 3 | Go to Step 6 | ||||||||||||
3 | Measure voltage at the following points at the ECM connector on the TWV harness:
Does each voltage measure less than the specified value? | 1 V | Go to Step 4 | Go to Step 6 | ||||||||||||
4 |
Does each resistance measure more than the specified value? | 10 M ohms or more | Go to Step 5 | Go to Step 6 | ||||||||||||
5 | 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 7 | Go to Step 6 | ||||||||||||
6 | Repair/replace the TWV harness. Did you complete the action? | -- | Go to Step 7 | -- | ||||||||||||
7 |
Does DTC 0158 or DTC 0159 reset? | -- | Go to Step 8 | System OK | ||||||||||||
8 | Replace the ECM. Refer to Engine Control Module Replacement/Restore Fuel Rate Data . Did you complete the replacement? | -- | Go to Step 9 | -- | ||||||||||||
9 |
Does DTC 0158 or DTC 0159 reset? | -- | Go to Step 2 | System OK | ||||||||||||
