97 superduty, recently installed motor. Have a dead miss. Put it on a NGS tester today, ran the injector test and this is what it is telling me. I also have codes p1271 - 1278 and 1293. What does this mean and what do I do next. Any help appreciated. Also why the "a" on cyl 1a?
Thanks!
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NA11 DIAGNOSTIC TROUBLE CODES (DTCs) P1271-P1278
DTCs P1271-P1278 indicate a low side-to-high side open in the circuit between the IDM and the injector. The following table lists the circuits to inspect while performing these pinpoint tests, based on the DTC retrieved during the KOEO On-Demand or Injector Electrical Self Tests.
Note: If all of the DTCs associated with an entire bank are retrieved, the high side circuit is most likely open.



Cyl. DTC Low Side High Side Bank
1 P1271 555 (T) 1087 (O) Right
2 P1272 556 (W) 878 (PK/Y) Left
3 P1273 557 (BR/Y) 1087 (O) Right
4 P1274 558 (BR/LB) 878 (PK/Y) Left
5 P1275 559 (T/BK) 1087 (O) Right
6 P1276 560 (LG/O) 878 (PK/Y) Left
7 P1277 561 (T/R) 1087 (O) Right
8 P1278 562 (LB) 878 (PK/Y) Left


Disconnect injector valve cover connector.
Install Glow Plug Injector Adapter 014-00935 or equivalent to valve cover gasket.
Measure resistance between the high side and low side on the injector. Refer to injector illustration at beginning of this pinpoint test for proper pin location.
Is the resistance less than 5 ohms?
Yes No
GO to NA13 . GO to NA12 .

NA12 CHECK INJECTOR FOR OPEN CIRCUIT
Remove valve cover.
Disconnect injector connector.
Measure resistance between high side circuit from adapter tool and injector connector.
Measure resistance between low side circuit from adapter tool and injector connector.
Is each resistance less than 5 ohms?
Yes No
REPLACE injector. RESTORE vehicle. CLEAR DTCs and RETEST. GO to NA23 .

NA13 CHECK FOR OPEN IN LOW SIDE CIRCUIT
Disconnect IDM harness connector.
Measure resistance on injector low side circuit between valve cover connector and IDM.
Is resistance less than 5 ohms?
Yes No
GO to NA14 . REPAIR open in low side circuit. RESTORE vehicle. CLEAR DTCs and RETEST.

NA14 CHECK FOR OPEN IN HIGH SIDE CIRCUIT
Measure resistance between suspect injector high side circuit on injector harness connector and IDM connector.
Is resistance less than 5 ohms?
Yes No
Fault may be intermittent. GO to NA15 . REPAIR open in high side circuit. RESTORE vehicle. CLEAR DTCs and RETEST.

NA15 CHECK FOR OPEN INJECTOR CIRCUIT
Measure resistance between suspect low side and high side circuit at the IDM connector. Refer to injector illustration at beginning of this pinpoint test for pin location.
Grasp the harness close to the suspect injector harness connector. Wiggle and shake harness while working your way back to the IDM.
Do resistance readings ever go above 5 ohms?
Yes No
ISOLATE open in circuit and REPAIR. RESTORE vehicle. CLEAR DTCs and RETEST. REPLACE IDM. RESTORE vehicle. CLEAR DTCs and RETEST.

NA16 DIAGNOSTIC TROUBLE CODES (DTCs) P1291 AND P1292
DTCs P1291 and P1292 indicate a ground short or short to battery positive exists on the high side circuit between the IDM and the injectors. The following table list the circuits to inspect while performing these pinpoint tests, based on the DTC retrieved during the KOEO test.

DTC High Side Bank
P1291 1087 (O) Right
P1292 878 (PK/Y) Left


Disconnect IDM harness connector.
Measure resistance between the suspect high side circuit at the IDM harness connector and battery negative post. Refer to injector illustration at beginning of this pinpoint test for proper pin location.
Is resistance greater than 10,000 ohms?
Yes No
GO to NA18 . GO to NA17 .

NA17 CHECK SHORT TO GROUND IN HIGH SIDE CIRCUIT
Disconnect both valve cover connectors on the bank with the code.
Measure resistance between suspect high side circuit at IDM connector and battery negative post.
Is resistance greater than 10,000 ohms?
Yes No
GO to NA2 . REPAIR short to ground between IDM and injector valve cover connector. RESTORE vehicle. CLEAR DTCs and RETEST.

NA18 CHECK SHORT TO POWER IN HIGH SIDE CIRCUIT
Key on, engine off.
Measure resistance between the suspect high side circuit at IDM connector and battery positive post, then to other high side circuit.
Are both resistance readings greater than 10,000 ohms?
Yes No
Fault may be intermittent. GO to NA19 . REPAIR short to power on high side circuit. RESTORE vehicle. CLEAR DTCs and RETEST.

NA19 CHECK FOR INTERMITTENT SHORT TO POWER IN HIGH SIDE CIRCUIT
Measure resistance between suspect high side circuit on the IDM connector and battery positive post, then to other high side circuit.
Grasp the harness close to the suspect injector harness connector. Wiggle, shake harness while working towards the IDM.
Do both resistance readings ever drop below 10,000 ohms?
Yes No
ISOLATE short circuit and REPAIR. RESTORE vehicle. CLEAR DTCs and RETEST. REPLACE IDM. RESTORE vehicle. CLEAR DTCs and RETEST.

NA20 DIAGNOSTIC TROUBLE CODES (DTCs) P1294 AND P1293: CHECK FOR VOLTAGE ON HIGH SIDE CIRCUIT
DTCs P1294 and P1293 indicate an open circuit exists on the high side circuit between the IDM and the injectors. The following table lists the circuits to inspect while performing these pinpoint tests, based on the DTC retrieved during the KOEO On-Demand and Injector Electrical Self Tests.

DTC High Side Injector Bank
P1294 878 (PK/YE) Left
P1293 1087 (OG) Right


Key off.
Disconnect connector on the bank with the code.
Key on, engine off.
Measure voltage on the suspect high side circuit Pin E on the injector vehicle harness connectors and battery ground.
Is voltage greater than one volt?
Yes No
GO to NA21 . GO to NA24 .

NA21 CHECK INJECTOR RESISTANCE
Key off.
Suspect injector valve cover connectors disconnected.
Install Glow Plug Injector Adapter 014-00935 or equivalent.
Measure resistance between high side and low side injector terminals on the adapter tool.
Is resistance less than 5 ohms?
Yes No
Fault may be intermittent. GO to NA15 . GO to NA22 .

NA22 CHECK HARNESS FOR OPEN
Remove valve cover.
Disconnect injector harness connector.
Measure resistance between injector connector and exterior gasket connector.
Is resistance less than 5 ohms?
Yes No
REPLACE injector. RESTORE system. CLEAR DTCs and RETEST. GO to NA23 .

NA23 DETERMINE WHETHER GASKET OR UVC HARNESS HAS FAILED
Disconnect UVC harness from gasket.
Measure resistance across each contact in the gasket.
Is each resistance reading less than 5 ohms?
Yes No
REPLACE UVC harness. RESTORE system. CLEAR DTCs and RETEST. REPLACE valve cover gasket. RESTORE system. CLEAR DTCs and RETEST.

NA24 CHECK FOR OPEN IN HIGH SIDE CIRCUIT
Key off.
Disconnect IDM harness connector.
Both connectors on the bank with the code disconnected.
Measure resistance between suspect high side circuit at the IDM connector and Pin C and both suspect injector connectors.
Are both resistance readings less than 5 ohms?
Yes No
Fault may be intermittent. GO to NA15 . REPAIR open in high side circuit. RESTORE system. CLEAR DTCs and RETEST.

 

Thanks, I'll start working through the test.
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May be a break (short)in the wiring that crosses over the left head . Look there first ..