DTC P0201, P0202, P0203, P0204, P0205, or P0206. Isuzu Isuzu MD F-Series 2004

For 1990-2009 cars only

Makes 🢒 Isuzu 🢒 2004 🢒 Isuzu MD F-Series 🢒 Engine 🢒 Engine Controls - 7.8L 🢒 DTC P0201, P0202, P0203, P0204, P0205, or P0206

DTC P0201, P0202, P0203, P0204, P0205, or P0206 Without RPO CTF

Circuit Description

A hydraulic piston and a two-way valve (TWV) solenoid valve has been added to the conventional nozzle. When 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 in order for the hydraulic piston to inject the fuel from the nozzle. If the TWV coil circuit is open, DTC P0201-P0206 will set, depending on which cylinder has the fault.

Conditions for Running the DTC

•	Battery voltage is more than 10 volts.

•	The ignition is ON.

Conditions for Setting the DTC

The TWV coil circuit is open.

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.

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 connections 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 connections.

•	Erratic engine RPM

•	Lack of engine power

Step	Action	Values	Yes	No
Schematic Reference: Engine Controls Schematics
1	Is DTC P0201, P0202, P0203, P0204, P0205, or P0206 set with the ignition ON, or with the engine operating?	--	Go to Step 2	Go to Diagnostic Aids
2	Turn the ignition OFF. Disconnect the ECM connector containing the TWV harness connections. Measure the resistance between the TWV voltage supply circuit and the appropriate TWV control circuit at the ECM harness connector. Does the resistance measure within the specified range?	0.9-1.3 ohms	Go to Step 6	Go to Step 3
3	Disconnect the appropriate TWV harness connector from the TWV on the cylinder head. Measure the resistance of the appropriate TWV control circuit and TWV supply circuit between the TWV and the ECM. Does each resistance measure below the specified value?	0.1 ohms	Go to Step 4	Go to Step 7
4	Measure the resistance at the TWV connector between pin number 1, 2 and 3, 4 at connector 1 for TWV. Does the resistance measure within the specified range?	0.4-0.8 ohms	Go to Step 6	Go to Step 5
5	Remove the cylinder head cover. Inspect the upper portion of the cylinder head. Repair the condition as necessary. Refer to Cylinder Head Replacement in Engine Mechanical. Did you find and correct the condition?	--	Go to Step 6	Go to Step 8
6	Connect all connectors and terminals on the TWV harness. Install the cylinder head cover. Turn the ignition ON. Did the DTC set?	--	Go to Step 7	Go to Step 10
7	Repair the open TWV circuit. Did you complete the repair?	--	Go to Step 10	--
8	Replace the appropriate TWV. Did you complete the replacement?	--	Go to Step 10	--
9	Replace the ECM. Did you complete the replacement?	--	Go to Step 10	--
10	Clear the DTCs. Turn the ignition ON. Did the DTC set?	--	Go to Step 1	Go to Step 11
11	Operate the vehicle. Do any other DTCs set?	--	Go to Diagnostic Trouble Code (DTC) List	System OK

DTC P0201, P0202, P0203, P0204, P0205, or P0206 With RPO CTF

Circuit Description

The injector solenoid coil control circuit is a low voltage system and drives injectors. The engine control module (ECM) calculates the optimum fuel injection timing using the data sent from sensors, and energizes injector solenoid coils. The ECM also controls the fuel injection quantity based on the solenoid coil energize duration. If the injector solenoid coil circuit is open, this DTC will set, depending on which cylinder has the fault.

Conditions for Running the DTC

•	The battery voltage is between 10-16 volts.

•	The ignition switch is ON.

•	The engine is running.

•	The crankshaft position (CKP) sensor signal pulse is detected.

Conditions for Setting the DTC

The ECM detects that the injector coil control circuit is an open circuit.

Action Taken When the DTC Sets

•	The ECM illuminates the malfunction indicator lamp (MIL) when the diagnostic runs and fails.

•	The ECM records the operating conditions at the time the diagnostic fails. The ECM stores this information in the Failure Records.

•	The ECM closes the exhaust gas recirculation (EGR) valve and holds the EGR valve to a closed position.

Condition for Clearing the DTC

•	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

•	If an intermittent condition is suspected, the following may cause an intermittent:

-	Poor connections

-	A misrouted harness

-	Rubbed through wire insulation

-	Broken wire inside the insulation

•	Inspect for the following conditions:

-	Poor connection at ECM--Inspect the harness connectors for the following conditions:

•	Backed-out terminals

•	Improper mating

•	Broken locks

•	Improperly formed or damaged terminals

•	Poor terminal to wire connection

-	Damaged harness--Inspect the wiring harness for damage. If the harness appears to be OK, observe the Engine Coolant Temperature display on the scan tool while moving the connectors and the wiring harness related to the sensor. A change in the display will indicate the location of the fault.

Step

Action

Values

Yes

Schematic Reference: Engine Controls Schematics

Did you perform the Diagnostic System Check - Engine Controls?

Go to Step 2

Go to Diagnostic System Check - Engine Controls

Observe the failure Records for this DTC.
Turn OFF the ignition for 30 seconds.
Start the engine.
Operate the vehicle within the Conditions for Running the DTC. You may also operate the vehicle within the conditions that you observed from the Freeze Frame/Failure Records.

Did the DTC fail this ignition?

Go to Step 3

Go to Diagnostic Aids

Turn OFF the ignition.
Disconnect the appropriate injector harness in-line connector from the cylinder head cover case.
Measure the resistance through the intermediate connector between the injector power supply circuit and the appropriate injector control circuit.

Is the resistance less than the specified range?

2 ohms

Go to Step 5

Go to Step 4

Test the appropriate injector control circuits between the engine control module (ECM) and the in-line connector for the following conditions:

•	An open circuit

•	High resistance

Repair the circuits, as necessary.

Did you find and correct the condition?

Go to Step 12

Go to Step 10

Remove the cylinder head cover.
Inspect the upper portion of the appropriate injector and the injector harness.
Repair the condition, as necessary. Refer to Cylinder Head Replacement in Engine Mechanical.

Did you find and correct the condition?

Go to Step 12

Go to Step 6

Turn OFF the ignition.
Disconnect the appropriate injector terminal from the injector.
Measure the resistance of the injector solenoid coil.

Is the resistance less than the specified range?

2 ohms

Go to Step 7

Go to Step 8

Test the appropriate injector control circuits between the injector terminal and the intermediate connector for the following conditions:

•	An open circuit

•	High resistance

Repair the circuits, as necessary.

Did you find and correct the condition?

Go to Step 12

Go to Step 9

Turn OFF the ignition.
Inspect for poor connections at the intermediate connector.
Repair the connections, as necessary.

Did you find and correct the condition?

Go to Step 12

Go to Step 10

Turn OFF the ignition.
Disconnect the ECM.
Inspect for poor connections at the harness connector of the ECM.
Repair the connections, as necessary.

Did you find and correct the condition?

Go to Step 12

Go to Step 11

Replace the appropriate injector. Refer to Fuel Injector Replacement .

Did you complete the replacement?

Go to Step 12

Important: The new ECM must be programmed.

Replace the ECM. Refer to Engine Control Module Replacement/Restore Fuel Rate Data .

Did you complete the replacement?

Go to Step 12

Clear the DTCs with a scan tool.
Turn OFF the ignition for 30 seconds.
Start the engine.
Operate the vehicle within the Conditions for Running the DTC. You may also operate the vehicle within the conditions that you observed from the Freeze Frame/Failure Records.

Did the DTC fail this ignition?

Go to Step 2

Go to Step 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