DTC Troubleshooting: P16F4
DTC P16F4: Starter Cut Relay 2 Control Circuit Low Voltage
NOTE: Before you troubleshoot, review the general troubleshooting information.

DTC Description
Confirmed DTC
Pending DTC
P16F4 Starter Cut Relay 2 Control Circuit Low Voltage
   

1.
Engine starting check:

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

Does the engine start?

     
YES
     
     
     
Go to step 2.
     
NO
     
     
     
Go to step 4.
2.
Problem verification:

Problem verification
?1.
Turn the vehicle to the OFF (LOCK) mode.

?2.
Turn the vehicle to the ON mode.

?3.
Clear the DTC with the HDS.


?4.
Check for Pending or Confirmed DTCs with the HDS.
DTC Description
Confirmed DTC
Pending DTC
P16F4 Starter Cut Relay 2 Control Circuit Low Voltage
   

Is DTC P16F4 indicated?

     
YES
     
     
     
The failure is duplicated. Go to step 3.
     
NO
     
     
     
Intermittent failure, the system is OK at this time. Check for poor connections or loose terminals at the relay circuit board (starter cut relay 2 circuit) and the PCM. If the on-board snapshot of this DTC is recorded, try to reproduce the failure under the same conditions with the on-board snapshot.?
3.
Shorted wire check (ST CUT RLY2 CL- line):

Shorted wire check (ST CUT RLY2 CL- line)
?1.
Turn the vehicle to the OFF (LOCK) mode.

?2.
Jump the SCS line with the HDS, and wait more than 1 minute.


?3.
Disconnect the following connectors.
PCM connector A (50P)
Relay circuit board connector A (8P)

?4.
Check for continuity between test points 1 and 2.
Test condition
Vehicle OFF (LOCK) mode
 
PCM connector A (50P): disconnected
 
Relay circuit board connector A (8P): disconnected
Test point 1
PCM connector A (50P) No. 23
Test point 2
Body ground

Is there continuity?

     
YES
     
     
     
Repair a short in the ST CUT RLY2 CL- wire between the PCM (A23) and the relay circuit board.?
     
NO
     
     
     
The ST CUT RLY2 CL- wire is OK. Check for any authorized service information related to the DTCs or symptoms you are troubleshooting, or substitute a known-good PCM, then recheck. If DTC P16F4 goes away and the PCM was substituted, replace the original PCM.?
4.
Determine possible failure area (PCM, others):

Determine possible failure area (PCM, others)
?1.
Turn the vehicle to the OFF (LOCK) mode.

?2.
Jump the SCS line with the HDS, and wait more than 1 minute.


?3.
Disconnect the following connector.
PCM connector A (50P)

?4.
Turn the vehicle to the ON mode.

?5.
Measure the voltage between test points 1 and 2.
Test condition
Vehicle ON mode
 
PCM connector A (50P): disconnected
Test point 1
PCM connector A (50P) No. 23
Test point 2
Body ground

Is there battery voltage?

     
YES
     
     
     
Check for any authorized service information related to the DTCs or symptoms you are troubleshooting, or substitute a known-good PCM, then recheck. If DTC P16F4 goes away and the PCM was substituted, replace the original PCM.?
     
NO
     
     
     
Go to step 5.
5.
Open wire check (ST CUT RLY2 CL- line):

Open wire check (ST CUT RLY2 CL- line)
?1.
Turn the vehicle to the OFF (LOCK) mode.

?2.
Disconnect the following connector.
Relay circuit board connector A (8P)

?3.
Check for continuity between test points 1 and 2.
Test condition
Vehicle OFF (LOCK) mode
PCM connector A (50P): disconnected
Relay circuit board connector A (8P): disconnected
Test point 1
Relay circuit board connector A (8P) No. 4
Test point 2
PCM connector A (50P) No. 23


Is there continuity?

     
YES
     
     
     
The ST CUT RLY2 CL- wire is OK. Go to step 6.
     
NO
     
     
     
Repair an open in the ST CUT RLY2 CL- wire between the PCM (A23) and the relay circuit board.?
6.
Fuse check:

Fuse check
?1.
Check the following fuse.
Fuse
No. B21 (10 A)
Location
Under-dash fuse/relay box

Is the fuse OK?

     
YES
     
     
     
Go to step 7.
     
NO
     
     
     
Check for a short in the IG1 ACG wire between the No. B21 (10 A) fuse and the relay circuit board, and repair it as needed. Also replace the No. B21 (10 A) fuse.?
7.
Open wire check (IG1 ACG line):

Open wire check (IG1 ACG line)
?1.
Disconnect the following connectors.
Relay circuit board connector B (6P)
Under-dash fuse/relay box connector C (27P)

?2.
Connect terminals A and B with a jumper wire.
Terminal A
Under-dash fuse/relay box connector C (27P) No. 6
Terminal B
Body ground


?3.
Check for continuity between test points 1 and 2.
Test condition
Vehicle OFF (LOCK) mode
 
PCM connector A (50P): disconnected
 
Relay circuit board connector A (8P): disconnected
 
Relay circuit board connector B (6P): disconnected
 
Under-dash fuse/relay box connector C (27P): disconnected
 
Under-dash fuse/relay box connector C (27P) No. 6: jumped to body ground
Test point 1
Relay circuit board connector B (6P) No. 4
Test point 2
Body ground


Is there continuity?

     
YES
     
     
     
The IG1 ACG wire is OK. Replace the under-dash fuse/relay box.?
     
NO
     
     
     
Repair an open in the IG1 ACG wire between the under-dash fuse/relay box and the relay circuit board.?