Code p1316 please help
#1
#2
Possible causes:
a. Injector(s) or circuit(s)
b. Open or shorted IDM enable circuit
c. Open/short in EF circuit
d. Open/short in FDCS circuit
e. IDM relay
f. IDM powering circuits
g. IDM
h. PCM
Check for other codes.
Key on, engine off. (KOEO)
Perform KOEO On-Demand Self-Test.
P1316 OR P1670, CHECK FOR AN INTERMITTENT OPEN CIRCUIT
KEY OFF.
Install breakout box, leave PCM disconnected.
Disconnect IDM.
Check for intermittent open in the following circuits:
Measure resistance on (FDCS) Circuit 821 (BR/O) between IDM connector Pin 17 and PCM Test Pin 95.
Measure resistance on (EF) Circuit 818 (GY/W) between IDM connector Pin 4 and PCM Test Pin 48.
Grasp the harness close to the IDM connector. Wiggle, shake the harness while working your way back to the PCM, while looking for a spike on the DVOM.
Description The IDM provides the EF output signal to the PCM to confirm that proper timing/duration of fuel delivery command signal (FDCS) was received. Additionally, the EF signal is used to send diagnostics of the IDM and injectors (electrical) to the PCM.
DTC Description
P1668 = PCM-IDM diagnostic communication error
P1670 = Electronic feedback signal not detected
P1316 = Indicates that IDM DTCs are stored within the IDM
DTC P1668 and P1670 indicates that a communication error has occurred between the PCM and the IDM.
Possible causes:
a. Open fuse
b. IDM relay
c. Open or shorted IDM enable circuit
d. Open/short in EF circuit
e. Open/short in FDCS circuit
f. IDM powering circuits
g. PCM
h. Check for other codes.
KOEO:
Perform KOEO On-Demand Self-Test and retrieve Continuous DTCs.
CHECK CIRCUIT 818 (GY/W) FOR OPEN
Install breakout box; leave PCM disconnected.
Disconnect the IDM harness connector.
Measure resistance on Circuit 818 (GY/W) between PCM Test Pin 48 and IDM harness connector Pin 4.
Key on, engine off. Measure for voltage on Circuit 818 (GY/W) between PCM Test Pin 48 and battery ground.
Turn ignition switch to OFF. Measure resistance on Circuit 359 (GY/R) between PCM Test Pin 91 and IDM connector Pin 2.
CHECK IDM POWER
PCM connected, IDM disconnected.
KOEO. Measure voltage between IDM connector Pin 14 and battery ground.
CHECK IDM GROUND
KEY OFF. Measure resistance between IDM connector Pin 26 and battery ground.
#3
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#9
To the OP, now comes the fun part. Figuring out which valve cover you need to remove to plug this thing back in. Since you don't have a good scanner that can run things like a buzz test, the next best option is to grab a multi-meter and set it to read ohms. Located on the inboard side of each valve cover you will see some wires leading to a plug connector. This is a flat 9 pin connector that you will need to unplug to expose the pins inside.
The 9-pin plug is wired as follows:
G G I I C I I G G
G=Glow Plug +
I = Injector +
C= Injector Common -
The injectors fire with a 115VDC signal from the IDM. Do Not pierce the wires to test.
Test between "I" and "C" to test the injectors, should be less than 5.0 Ohms.
To check glow plugs Test between "G" and battery ground. Should be between 0.6 and 2.0 Ohms
If you find readings outside these numbers, pull that valve cover and check for the loose connector.
The 9-pin plug is wired as follows:
G G I I C I I G G
G=Glow Plug +
I = Injector +
C= Injector Common -
The injectors fire with a 115VDC signal from the IDM. Do Not pierce the wires to test.
Test between "I" and "C" to test the injectors, should be less than 5.0 Ohms.
To check glow plugs Test between "G" and battery ground. Should be between 0.6 and 2.0 Ohms
If you find readings outside these numbers, pull that valve cover and check for the loose connector.
#10
OP, have you run an injector buzz test yet? That might point you in the right direction. The P1316 code just means there are IDM codes present. To find those codes, you will want to run the injector buzz test.
#12
Is your truck chipped?
the P0603 code is normal for a chipped truck and can be ignored.
The 1316 code is most often associated with UVCH (Under Valve Cover Harness). You can check them with an ohm meter. There is a 9 pin connector on the inboard side of each valve cover. Disconnect and check the pins on the valve cover side. The two pins on each end to ground should be 0.8-2 ohms. The next two the the center pin should be <5.0 ohms. If you find some outside those numbers you need to remove that valve cover and check all the connections underneath. Do a search on the 50 cent mod.
Sorry. My phone is being stupid. I see this has been covered.
the P0603 code is normal for a chipped truck and can be ignored.
The 1316 code is most often associated with UVCH (Under Valve Cover Harness). You can check them with an ohm meter. There is a 9 pin connector on the inboard side of each valve cover. Disconnect and check the pins on the valve cover side. The two pins on each end to ground should be 0.8-2 ohms. The next two the the center pin should be <5.0 ohms. If you find some outside those numbers you need to remove that valve cover and check all the connections underneath. Do a search on the 50 cent mod.
Sorry. My phone is being stupid. I see this has been covered.
Last edited by HD Rider; 10-10-2017 at 10:42 PM. Reason: Already covered
#14
#15
There's a chance of that. You can still use a quarter in the updated cover, but you have to basically cut it into a little triangle to fit between the updated tabs.
That or you're not sliding it in there right. Pull the plug and look inside where the quarter or shim would go and see what the obstruction is. If you see two little plastic tabs sticking down to block the quarter, then it's the updated harness.
That or you're not sliding it in there right. Pull the plug and look inside where the quarter or shim would go and see what the obstruction is. If you see two little plastic tabs sticking down to block the quarter, then it's the updated harness.