11/10/23, 1:19 PM Powertrain Control Module (PCM) - EGR Cooler Bypass Status Line Circuit High (ALL Diagnostic
iagnostic Trouble Codes ( DTC )) - ALLDATA Repair
2012 Dodge or Ram Truck RAM 3500 Truck 4WD L6-6.7L DSL Turbo
Vehicle > ALL Diagnostic Trouble Codes ( DTC ) > Testing and Inspection > P Code Charts > P144F
POWERTRAIN CONTROL MODULE (PCM) - EGR COOLER BYPASS STATUS LINE
CIRCUIT HIGH
P144F-EGR COOLER BYPASS STATUS LINE CIRCUIT HIGH
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11/10/23, 1:19 PM Powertrain Control Module (PCM) - EGR Cooler Bypass Status Line Circuit High (ALL Diagnostic Trouble Codes ( DTC )) - ALLDATA Repair
S040
F344 F344 F344
18 18 18
BR/GY BR/GY BR/GY
10
C112
F344 F344
1 18 18
ACTUATOR- BR/GY BR/GY
SMART
ELECTRONIC
POWER
TURBO 2
RELAY
FEED ACTUATOR ACTUATOR SENSOR-
HIGH LOW MASS AIR
DATA DATA FLOW
GROUND LINK LINK
2 3 4 3 3 1
42
VALVE-EGR C130
SMART
COOLER
EGR POWER
BYPASS
RELAY
EGR VALVE (DH/D1) F344 K916
FEED
BYPASS BYPASS 18 18
STATUS SIGNAL GROUND
BR/GY BR/OR
1 2 4
S042
Z918 Z902
18 18
4
BK BK
RELAY-
SMART
SMART
POWER
D130 D131 K671 K670 POWER K916 K157
RELAY
18 18 18 18 FEED 18 18
BR/VT WT/LG BR/DB BR/LB G902 BR/OR BR/OR
34 C2 17 C2 73 C1 45 C1 53 C1 34 C1
MODULE-
ACTUATOR ACTUATOR EGR EGR SENSOR MASS AIR
POWERTRAIN
HIGH LOW BYPASS BYPASS GROUND FLOW
CONTROL
DATA DATA STATUS VALVE SENSOR
LINK LINK SIGNAL SIGNAL
G918
LT. GRAY
1 2 7 23
4
40
4 1
58
3
5 6 59 76
ACTUATOR-
2 5 ELECTRONIC
MODULE-
TURBO
POWERTRAIN
(6.7L)
1 CONTROL C1 LT. GRAY
(6.7L) 1 2 7 23
4 1
RELAY- 40
SMART
58
POWER VALVE-EGR
(6.7L DIESEL) 4 1 COOLER
BYPASS
5 6 59 76
MODULE- (6.7L)
SENSOR- POWERTRAIN
MASS AIR FLOW CONTROL C2
(6.7L) (6.7L)
02522868
For a complete wiring diagram, refer to the Wiring Information.
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11/10/23, 1:19 PM Powertrain Control Module (PCM) - EGR Cooler Bypass Status Line Circuit High (ALL Diagnostic Trouble Codes ( DTC )) - ALLDATA Repair
Theory of Operation
The Exhaust Gas Recirculation (EGR) Cooler Bypass Valve is used to redirect the EGR gases around the cooler when
the engine is under certain operating conditions. The EGR Cooler Bypass Valve is a smart device which
communicates it's status to the Powertrain Control Module (PCM). At key on the EGR Cooler Bypass Valve drives the
signal line low and then high and the PCM monitors for the correct status response from the EGR Cooler Bypass
Valve. Throughout engine operation the PCM sends commands via the signal circuit to the EGR Cooler Bypass Valve
and monitors the status line to confirm that the EGR Cooler Bypass Valve has reached the commanded position.
When a fault occurs, the EGR Cooler Bypass valve will send a signal of less than one Volt on the status line to the
PCM. This monitor is a one trip fault.
When Monitored:
With the ignition on.
Set Condition:
The PCM has detected battery voltage on the status line when no voltage should be present.
Possible Causes
(K671) EGR COOLER BYPASS VALVE STATUS LINE SHORTED TO BATTERY VOLTAGE
SMART POWER RELAY
EGR COOLER BYPASS VALVE
POWERTRAIN CONTROL MODULE (PCM)
Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding. (Refer to 28 - DTC-Based
Diagnostics/MODULE, Powertrain Control (PCM) - Standard Procedure).
1.DTC ACTIVE
1. Ignition on, engine not running.
2. With the scan tool, read DTCs.
Is DTC P144F active?
Yes
Go To 2
No
Perform the INTERMITTENT CONDITION - 6.7L diagnostic procedure. (Refer to 28 - DTC-Based
Diagnostics/MODULE, Powertrain Control (PCM) - Standard Procedure).
2.CHECK THE (K671) EGR COOLER BYPASS STATUS CIRCUIT FOR A SHORT TO BATTERY VOLTAGE
1. Turn the ignition off.
2. Disconnect the EGR Cooler Bypass valve harness connector.
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11/10/23, 1:19 PM Powertrain Control Module (PCM) - EGR Cooler Bypass Status Line Circuit High (ALL Diagnostic Trouble Codes ( DTC )) - ALLDATA Repair
NOTE: Check connectors - Clean/repair as necessary.
3. Turn the ignition on.
4. Measure the voltage at the (K671) EGR Cooler Bypass Valve Status Line circuit at the EGR Cooler Bypass
Valve harness connector.
Is the voltage equal to battery voltage?
Yes
Repair the (K671) EGR Cooler Bypass Valve Status Line circuit for a short to voltage.
Perform the POWERTRAIN VERIFICATION TEST - 6.7L. (Refer to 28 - DTC-Based Diagnostics/MODULE,
Powertrain Control (PCM) - Standard Procedure).
No
Go To 3
3.CHECK THE SMART POWER RELAY
1. Turn the ignition off.
2. Measure for voltage at the (F344) Smart Power Relay Coil circuit at the EGR Cooler Bypass Valve harness
connector.
Is there any voltage present?
Yes
The Smart Power Relay is stuck on. If there are any Smart Power Relay Control circuit DTCs present, diagnose
those before replacing the Smart Power Relay.
Perform the POWERTRAIN VERIFICATION TEST - 6.7L. (Refer to 28 - DTC-Based Diagnostics/MODULE,
Powertrain Control (PCM) - Standard Procedure).
No
Go To 4
4.CHECK THE EGR COOLER BYPASS VALVE
1. Turn the ignition to the off position for a minimum of 10 minutes to allow the PCM to completely power down.
2. Use a jumper wire to connect the (K671) EGR Cooler Bypass Status circuit to ground.
3. Turn the ignition on.
4. With the scan tool, read DTCs.
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11/10/23, 1:19 PM Powertrain Control Module (PCM) - EGR Cooler Bypass Status Line Circuit High (ALL Diagnostic Trouble Codes ( DTC )) - ALLDATA Repair
Did P144F go inactive? 3
2
1 1 2
Yes 0
Replace the EGR Cooler Bypass Valve in accordance with
the service information.
NOTE: After inducing the P144F fault, the PCM must be
powered down for 10 minutes in able to clear the DTC.
Perform the POWERTRAIN VERIFICATION TEST - 6.7L.
(Refer to 28 - DTC-Based Diagnostics/MODULE, 4 1
Powertrain Control (PCM) - Standard Procedure).
VALVE-EGR
No
COOLER
Replace and program the Powertrain Control Module in BYPASS
accordance with the service information. (Refer to 28 - (6.7L DH/D1)
DTC-Based Diagnostics/MODULE, Powertrain Control
(PCM) - Standard Procedure).
183388
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