DTC Troubleshooting: P0201, P0204
DTC P0201: No. 1 Cylinder Injector Circuit Malfunction
DTC P0204: No. 4 Cylinder Injector Circuit Malfunction
NOTE: Before you troubleshoot, review the general troubleshooting information.

DTC Description
Confirmed DTC
Pending DTC
Freeze Frame
P0201 No. 1 Cylinder Injector Circuit Malfunction
     
P0204 No. 4 Cylinder Injector Circuit Malfunction
     

1.
Problem verification:

Problem verification
?1.
Turn the vehicle to the ON mode.

?2.


?3.
Start the engine. (If the engine does not start, crank the engine for 20 seconds).

?4.
Check for Pending or Confirmed DTCs with the HDS.
DTC Description
Confirmed DTC
Pending DTC
Freeze Frame
P0201 No. 1 Cylinder Injector Circuit Malfunction
     
P0204 No. 4 Cylinder Injector Circuit Malfunction
     

Is DTC P0201 or P0204 indicated?

     
YES
     
     
     
The failure is duplicated. Go to step 2.
     
NO
     
     
     
Intermittent failure, the system is OK at this time. Check for poor connections or loose terminals at the injector and the PCM. If the freeze data/on-board snapshot of this DTC is recorded, try to reproduce the failure under the same conditions with the freeze data/on-board snapshot.?
2.
Engine starting check:

Engine starting check
?1.
Try to start the engine.

Does the engine start?

     
YES
     
     
     
Go to step 10.
     
NO
     
     
     
Go to step 3.
3.
Relay check:

Relay check
?1.
Turn the vehicle to the OFF (LOCK) mode.

?2.
Remove the injector relay (A) from the under-hood fuse/relay box.


?3.

Is the relay OK?

     
YES
     
     
     
The injector relay is OK. Go to step 4.
     
NO
     
     
     
Replace the injector relay.?
4.
Open wire check (FI MAIN RLY OUT line):

Open wire check (FI MAIN RLY OUT line)
?1.
Turn the vehicle to the ON mode.

?2.
Measure the voltage between test points 1 and 2.
Test condition
Vehicle ON mode
Injector relay: disconnected
Test point 1
Injector relay 4P socket No. 3
Test point 2
Body ground


Is there battery voltage?

     
YES
     
     
     
The FI MAIN RLY OUT wire is OK. Go to step 5.
     
NO
     
     
     
Repair an open in the FI MAIN RLY OUT wire between PGM-FI main relay 1 and the injector relay. If needed, replace the under-hood fuse/relay box.?
5.
Open wire check (+B INJ line):

Open wire check (+B INJ line)
?1.
Turn the vehicle to the ON mode.

?2.
Measure the voltage between test points 1 and 2.
Test condition
Vehicle ON mode
Injector relay: disconnected
Test point 1
Injector relay 4P socket No. 1
Test point 2
Body ground


Is there battery voltage?

     
YES
     
     
     
The +B INJ wire is OK. Go to step 7.
     
NO
     
     
     
Go to step 6.
6.
Fuse check:

Fuse check
?1.
Check the following fuse.
Fuse
No. B10 (20 A)
Location
Under-hood fuse/relay box

Is the fuse OK?

     
YES
     
     
     
Repair an open in the +B INJ wire between the No. B10 (20 A) fuse and the injector relay. If needed, replace the under-hood fuse/relay box.?
     
NO
     
     
     
Repair a short in the +B INJ wire between the No. B10 (20 A) fuse and the injector relay. If needed, replace the under-hood fuse/relay box. Also replace the No. B10 (20 A) fuse.?
7.
Determine possible failure area (INJ RLY CL- line, others):

Determine possible failure area (INJ RLY CL- line, others)
?1.
Turn the vehicle to ON mode, and measure the voltage between test points 1 and 2 momentarily.
Test condition
Momentarily after ON mode
Injector relay: disconnected
Test point 1
Injector relay 4P socket No. 3
Test point 2
Injector relay 4P socket No. 4


Is there battery voltage momentarily?

     
YES
     
     
     
Go to step 9.
     
NO
     
     
     
Go to step 8.
8.
Open wire check (INJ RLY CL- line):

Open wire check (INJ RLY CL- line)
?1.
Turn the vehicle to the OFF (LOCK) mode.

?2.
Jump the SCS line with the HDS.


?3.
Disconnect the following connector.
PCM connector A (51P)

?4.
Check for continuity between test points 1 and 2.
Test condition
Vehicle OFF (LOCK) mode
Injector relay: disconnected
PCM connector A (51P): disconnected
Test point 1
Injector relay 4P socket No. 4
Test point 2


Is there continuity?

     
YES
     
     
     
The INJ RLY CL- wire is OK. Update the PCM if it does not have the latest software, or substitute a known-good PCM, then recheck. If DTC P0201 and/or P0204 goes away and the PCM was updated, troubleshooting is complete. If DTC P0201 and/or P0204 goes away and the PCM was substituted, replace the original PCM.?
     
NO
     
     
     
Repair an open in the INJ RLY CL- wire between the injector relay and the PCM (A15).?
9.
Open wire check (INJ RLY OUT line):

Open wire check (INJ RLY OUT line)
?1.
Turn the vehicle to the OFF (LOCK) mode.

?2.
Connect terminals A and B with a jumper wire.
Terminal A
Injector relay 4P socket No. 1
Terminal B
Injector relay 4P socket No. 2


?3.
Jump the SCS line with the HDS.


?4.
Disconnect the following connector.
PCM connector A (51P)

?5.
Measure the voltage between test points 1 and 2.
Test condition
Vehicle OFF (LOCK) mode
Injector relay: disconnected
Injector relay 4P socket terminal No. 1 and No. 2: jumped
PCM connector A (51P): disconnected
Test point 1
Test point 2
Body ground

Are there battery voltage?

     
YES
     
     
     
The INJ RLY OUT wire is OK. Go to step 10.
     
NO
     
     
     
Repair an open in the INJ RLY OUT wire between the injector relay and the PCM (A6, A7).?
10.
DTC check:

DTC check
?1.
Check the indicated DTC in step 1.

Is DTC P0201 indicated?

     
YES
     
     
     
Go to step 11.
     
NO
     
     
     
Go to step 19.
11.
Open wire check (INJH1, INJL1 line):

Open wire check (INJH1, INJL1 line)
?1.
Turn the vehicle to the OFF (LOCK) mode.

?2.
Install the injector relay.

?3.
Jump the SCS line with the HDS.


?4.
Disconnect the following connector.
PCM connector B (51P)

?5.
Check for continuity between test points 1 and 2.
Test condition
Vehicle OFF (LOCK) mode
PCM connector A (51P): disconnected
PCM connector B (51P): disconnected
Test point 1
Test point 2

Is there continuity?

     
YES
     
     
     
The INJH1 and INJL1 wires are not open. Go to step 14.
     
NO
     
     
     
Go to step 12.
12.
Open wire check (INJH1 line):

Open wire check (INJH1 line)
?1.
Disconnect the following connector.
No. 1 injector 2P connector

?2.
Check for continuity between test points 1 and 2.
Test condition
Vehicle OFF (LOCK) mode
PCM connector A (51P): disconnected
PCM connector B (51P): disconnected
No. 1 injector 2P connector: disconnected
Test point 1
Test point 2
No. 1 injector 2P connector No. 1


Is there continuity?

     
YES
     
     
     
The INJH1 wire is OK. Go to step 13.
     
NO
     
     
     
Repair an open in the INJH1 wire between the No. 1 injector and the PCM (B1).?
13.
Open wire check (INJL1 line):

Open wire check (INJL1 line)
?1.
Check for continuity between test points 1 and 2.
Test condition
Vehicle OFF (LOCK) mode
PCM connector A (51P): disconnected
PCM connector B (51P): disconnected
No. 1 injector 2P connector: disconnected
Test point 1
Test point 2
No. 1 injector 2P connector No. 2


Is there continuity?

     
YES
     
     
     
The INJL1 wire is OK. Failure in No. 1 injector. Replace all injectors as a set.?
     
NO
     
     
     
Repair an open in the INJL1 wire between the No. 1 injector and the PCM (B2).?
14.
Shorted wire check (INJH1 line to power):

Shorted wire check (INJH1 line to power)
?1.
Disconnect the following connector.
No. 1 injector 2P connector

?2.
Turn the vehicle to the ON mode.

?3.
Measure the voltage between test points 1 and 2.
Test condition
Vehicle ON mode
PCM connector A (51P): disconnected
PCM connector B (51P): disconnected
No. 1 injector 2P connector: disconnected
Test point 1
Test point 2
Body ground

Is there any voltage?

     
YES
     
     
     
Repair a short to power in the INJH1 wire between the No. 1 injector and the PCM (B1).?
     
NO
     
     
     
Go to step 15
15.
Shorted wire check (INJL1 line to power):

Shorted wire check (INJL1 line to power)
?1.
Measure the voltage between test points 1 and 2.
Test condition
Vehicle ON mode
PCM connector A (51P): disconnected
PCM connector B (51P): disconnected
No. 1 injector 2P connector: disconnected
Test point 1
Test point 2
Body ground

Is there any voltage?

     
YES
     
     
     
Repair a short to power in the INJL1 wire between the No. 1 injector and the PCM (B2).?
     
NO
     
     
     
Go to step 16.
16.
Shorted wire check (INJH1 line):

Shorted wire check (INJH1 line)
?1.
Turn the vehicle to the OFF (LOCK) mode.

?2.
Check for continuity between test points 1 and 2.
Test condition
Vehicle OFF (LOCK) mode
PCM connector A (51P): disconnected
PCM connector B (51P): disconnected
No. 1 injector 2P connector: disconnected
Test point 1
Test point 2
Body ground

Is there continuity?

     
YES
     
     
     
Repair a short in the INJH1 wire between the No. 1 injector and the PCM (B1).?
     
NO
     
     
     
The INJH1 wire is OK. Go to step 17.
17.
Shorted wire check (INJL1):

Shorted wire check (INJL1)
?1.
Check for continuity between test points 1 and 2.
Test condition
Vehicle OFF (LOCK) mode
PCM connector A (51P): disconnected
PCM connector B (51P): disconnected
No. 1 injector 2P connector: disconnected
Test point 1
Test point 2
Body ground

Is there continuity?

     
YES
     
     
     
Repair a short in the INJL1 wire between the No. 1 injector and the PCM (B2).?
     
NO
     
     
     
The INJL1 wire is OK. Go to step 18.
18.
Shorted wire check (INJH4 line):

Shorted wire check (INJH4 line)
?1.
Disconnect the following connector.
No. 4 injector 2P connector

?2.
Check for continuity between test points 1 and 2.
Test condition
Vehicle OFF (LOCK) mode
PCM connector A (51P): disconnected
PCM connector B (51P): disconnected
No. 1 injector 2P connector: disconnected
No. 4 injector 2P connector: disconnected
Test point 1
Test point 2
Body ground

Is there continuity?

     
YES
     
     
     
Repair a short in the INJH4 wire between the No. 4 injector and the PCM (B3).?
     
NO
     
     
     
The INJH4 wire is OK. Update the PCM if it does not have the latest software, or substitute a known-good PCM, then recheck. If DTC P0201 and/or P0204 goes away and the PCM was updated, troubleshooting is complete. If DTC P0201 and/or P0204 goes away and the PCM was substituted, replace the original PCM.?
19.
Open wire check (INJH4, INJL4 line):

Open wire check (INJH4, INJL4 line)
?1.
Turn the vehicle to the OFF (LOCK) mode.

?2.
Install the injector relay.

?3.
Jump the SCS line with the HDS.


?4.
Disconnect the following connector.
PCM connector B (51P)

?5.
Check for continuity between test points 1 and 2.
Test condition
Vehicle OFF (LOCK) mode
PCM connector A (51P): disconnected
PCM connector B (51P): disconnected
Test point 1
Test point 2

Is there continuity?

     
YES
     
     
     
The INJH4 and INJL4 wires are not open. Go to step 22.
     
NO
     
     
     
Go to step 20.
20.
Open wire check (INJH4 line):

Open wire check (INJH4 line)
?1.
Disconnect the following connector.
No. 4 injector 2P connector

?2.
Check for continuity between test points 1 and 2.
Test condition
PCM connector A (51P): disconnected
PCM connector B (51P): disconnected
No. 4 injector 2P connector: disconnected
Test circuit
INJH4
Test point 1
Test point 2
No. 4 injector 2P connector No. 1


Is there continuity?

     
YES
     
     
     
The INJH4 wire is OK. Go to step 21.
     
NO
     
     
     
Repair an open in the INJH4 wire between the No. 4 injector and the PCM (B3).?
21.
Open wire check (INJL4 line):

Open wire check (INJL4 line)
?1.
Check for continuity between test points 1 and 2.
Test condition
Vehicle OFF (LOCK) mode
PCM connector A (51P): disconnected
PCM connector B (51P): disconnected
No. 4 injector 2P connector: disconnected
Test point 1
Test point 2
No. 4 injector 2P connector No. 2


Is there continuity?

     
YES
     
     
     
The INJL4 wire is OK. Failure in No. 4 injector. Replace all injectors as a set.?
     
NO
     
     
     
Repair an open in the INJL4 wire between the No. 4 injector and the PCM (B4).?
22.
Shorted wire check (INJH4 line to power):

Shorted wire check (INJH4 line to power)
?1.
Disconnect the following connector.
No. 4 injector 2P connector

?2.
Turn the vehicle to the ON mode.

?3.
Measure the voltage between test points 1 and 2.
Test condition
Vehicle ON mode
PCM connector A (51P): disconnected
PCM connector B (51P): disconnected
No. 4 injector 2P connector: disconnected
Test point 1
Test point 2
Body ground

Is there voltage?

     
YES
     
     
     
Repair a short to power in the INJH4 wire between the No. 4 injector and the PCM (B3).?
     
NO
     
     
     
Go to step 23.
23.
Shorted wire check (INJL4 line to power):

Shorted wire check (INJL4 line to power)
?1.
Measure the voltage between test points 1 and 2.
Test condition
Vehicle ON mode
PCM connector A (51P): disconnected
PCM connector B (51P): disconnected
No. 4 injector 2P connector: disconnected
Test point 1
Test point 2
Body ground

Is there voltage?

     
YES
     
     
     
Repair a short to power in the INJL4 wire between the No. 4 injector and the PCM (B4).?
     
NO
     
     
     
Go to step 24.
24.
Shorted wire check (INJH4 line):

Shorted wire check (INJH4 line)
?1.
Turn the vehicle to the OFF (LOCK) mode.

?2.
Check for continuity between test points 1 and 2.
Test condition
Vehicle OFF (LOCK) mode
PCM connector A (51P): disconnected
PCM connector B (51P): disconnected
No. 4 injector 2P connector: disconnected
Test point 1
Test point 2
Body ground

Is there continuity?

     
YES
     
     
     
Repair a short in the INJH4 wire between the No. 4 injector and the PCM (B3).?
     
NO
     
     
     
The INJH4 wire is OK. Go to step 25.
25.
Shorted wire check (INJL4):

Shorted wire check (INJL4)
?1.
Check for continuity between test points 1 and 2.
Test condition
PCM connector A (51P): disconnected
PCM connector B (51P): disconnected
No. 4 injector 2P connector: disconnected
Test circuit
INJL4
Test point 1
Test point 2
Body ground

Is there continuity?

     
YES
     
     
     
Repair a short in the INJL4 wire between the No. 4 injector and the PCM (B4).?
     
NO
     
     
     
The INJL4 wire is OK. Go to step 26.
26.
Shorted wire check (INJH1 line):

Shorted wire check (INJH1 line)
?1.
Disconnect the following connector.
No. 1 injector 2P connector

?2.
Check for continuity between test points 1 and 2.
Test condition
Vehicle OFF (LOCK) mode
PCM connector A (51P): disconnected
PCM connector B (51P): disconnected
No. 1 injector 2P connector: disconnected
No. 4 injector 2P connector: disconnected
Test point 1
Test point 2
Body ground

Is there continuity?

     
YES
     
     
     
Repair a short in the INJH1 wire between the No. 1 injector and the PCM (B1).?
     
NO
     
     
     
The INJH1 wire is OK. Update the PCM if it does not have the latest software, or substitute a known-good PCM, then recheck. If DTC P0201 and/or P0204 goes away and the PCM was updated, troubleshooting is complete. If DTC P0201 and/or P0204 goes away and the PCM was substituted, replace the original PCM.?