Dodge Ram Truck 1500-2500-3500. Manual — part 2023
MODE 2 OVERCURRENT (SINGLE-ZONE) (CONTINUED)
4.
CHECK THE (C801) MODE DOOR 1 DRIVER CIRCUIT FOR A SHORT TO THE (C29) MODE DOOR 2
DRIVER CIRCUIT
Measure the resistance between the (C801) Mode Door 1 Driver cir-
cuit and the (C29) Mode Door 2 Driver circuit in the A/C Heater Con-
trol C1 harness connector.
Is the resistance below 10k ohms?
Yes
>> Repair the (C29) Mode Door 2 Driver circuit for a short to
the (C801) Mode Door 1 Driver circuit.
Perform BODY VERIFICATION TEST - VER 1. (Refer to 8
-
ELECTRICAL/ELECTRONIC
CONTROL
MODULES/
FRONT CONTROL MODULE - DIAGNOSIS AND TEST-
ING).
No
>> Go To 5
5.
CHECK THE (C34) COMMON DOOR DRIVER CIRCUIT FOR A SHORT TO THE (C32) RECIRCULATION
DOOR DRIVER CIRCUIT, THE (C61) BLEND DOOR DRIVER CIRCUIT, THE (C801) MODE DOOR 1 DRIVER
CIRCUIT, & THE (C29) MODE DOOR 2 DRIVER CIRCUIT
Measure the resistance between the (C34) Common Door Driver Cir-
cuit and the (C32) Recirculation Door Driver circuit, the (C61) Blend
Door Driver circuit, the (C801) Mode Door 1 Driver circuit, and the
(C29) Mode Door 2 Driver circuit in the A/C Heater Control C1 harness
connector.
Is the resistance below 30.0 ohms on any of the circuits?
Yes
>> Go To 6
No
>> Go To 7
24 - 92
HVAC - ELECTRICAL DIAGNOSTICS
DR/DH
MODE 2 OVERCURRENT (SINGLE-ZONE) (CONTINUED)
6.
CHECK THE DOOR DRIVER CIRCUITS WHOSE RESISTANCE WAS BELOW 30.0 OHMS IN THE
PREVIOUS STEP FOR A SHORT TO THE (C34) COMMON DOOR DRIVER CIRCUIT
Disconnect all door actuator harness connectors whose circuit resis-
tance was below 30.0 ohms.
Measure the resistance between the (C34) Common Door Driver cir-
cuit and each applicable door driver circuit in the A/C Heater Control
C1 harness connector.
Is the resistance below 10k ohms on any of the circuits?
Yes
>> Repair the door driver circuits with a resistance below 10k
ohms for a short to the (C34) Common Door Driver circuit.
Perform BODY VERIFICATION TEST - VER 1. (Refer to 8
-
ELECTRICAL/ELECTRONIC
CONTROL
MODULES/
FRONT CONTROL MODULE - DIAGNOSIS AND TEST-
ING).
No
>> Replace all door actuators with a resistance below 30.0
ohms in accordance with the Service Information.
Perform BODY VERIFICATION TEST - VER 1. (Refer to 8
-
ELECTRICAL/ELECTRONIC
CONTROL
MODULES/
FRONT
CONTROL
MODULE
-
DIAGNOSIS
AND
TESTING).
7.
RUN THE ACTUATOR CIRCUIT TEST
Reconnect the A/C Heater Control C1 harness connector.
Turn the ignition on.
With the DRBIII
T
in HVAC, select System Tests and then select Actuator Circuit Test. Allow the test to run to com-
pletion before proceeding.
Does the DRBIII
T
display any Actuator Circuit Test fault messages?
Yes
>> Diagnose and repair the fault(s). Refer to *ACTUATOR CIRCUIT TEST DIAGNOSTICS (SINGLE-ZONE)
in this section.
No
>> Replace the A/C Heater Control in accordance with the Service Information.
Perform BODY VERIFICATION TEST - VER 1. (Refer to 8 - ELECTRICAL/ELECTRONIC CONTROL
MODULES/FRONT CONTROL MODULE - DIAGNOSIS AND TESTING).
DR/DH
HVAC - ELECTRICAL DIAGNOSTICS
24 - 93
PCM COMMUNICATION FAILURE
For a complete wiring diagram Refer to Section 8W.
•
When Monitored:
With the ignition on.
•
Set Condition:
The Powertrain Control Module (PCM) (for gasoline engines) or Engine Control Module (ECM) (for diesel
engines) broadcasts a message on the PCI Bus that provides engine RPM and vehicle speed. This DTC will
set if the A/C Heater Control does not receive this message for more than 5 seconds.
Possible Causes
FAULTS PRESENT IN THE POWERTRAIN SYSTEM
PCM NOT BROADCASTING MESSAGE
ECM NOT BROADCASTING MESSAGE
A/C HEATER CONTROL NOT RECEIVING MESSAGE
Diagnostic Test
1.
VERIFY THAT THE PCM COMMUNICATION FAILURE DTC IS ACTIVE
Turn the ignition on.
With the DRBIII
T
, erase HVAC DTCs.
Cycle the ignition switch and wait approximately 30 seconds.
With the DRBIII
T
, read active HVAC DTCs.
Does the DRBIII
T
display: PCM Communication Failure?
Yes
>> Go To 2
No
>> A technician may not have erased this DTC following a module or PCI Bus repair. If possible, verify if
the vehicle was recently in for this type of service. Otherwise, visually inspect the related wiring harness
for chafed, pierced, pinched, and partially broken wires and the wiring harness connectors for broken,
bent, pushed out, and corroded terminals. Repair as necessary.
Perform BODY VERIFICATION TEST - VER 1. (Refer to 8 - ELECTRICAL/ELECTRONIC CONTROL
MODULES/FRONT CONTROL MODULE - DIAGNOSIS AND TESTING).
2.
CHECK FOR DTCS IN THE PCM OR ECM
With the DRBIII
T
, read PCM or ECM DTCs.
Does the DRBIII
T
display any DTCs?
Yes (Gasoline Engines)
Diagnose and repair the DTC(s). (Refer to 9 - ENGINE ELECTRICAL DIAGNOSTICS).
Perform BODY VERIFICATION TEST - VER 1. (Refer to 8 - ELECTRICAL/ELECTRONIC CONTROL
MODULES/FRONT CONTROL MODULE - DIAGNOSIS AND TESTING).
Yes (Diesel Engines)
Diagnose and repair the DTC(s). (Refer to 9 - ENGINE ELECTRICAL DIAGNOSTICS).
Perform BODY VERIFICATION TEST - VER 1. (Refer to 8 - ELECTRICAL/ELECTRONIC CONTROL
MODULES/FRONT CONTROL MODULE - DIAGNOSIS AND TESTING).
No
>> Go To 3
24 - 94
HVAC - ELECTRICAL DIAGNOSTICS
DR/DH
PCM COMMUNICATION FAILURE (CONTINUED)
3.
VERIFY THAT THE PCM OR ECM IS BROADCASTING THE MESSAGE ON THE PCI BUS
With the DRBIII
T
in HVAC, select Monitor Display and then select PCI Bus Messages.
From the list, select the following:
•
Engine RPM
•
Vehicle Speed
Does the DRBIII
T
display NO RESPONSE after either of these messages?
Yes (Gasoline Engines)
Perform the *No Response From PCM (PCI Bus) diagnostic procedure. (Refer to 8 - ELECTRICAL/
ELECTRONIC CONTROL MODULES - DIAGNOSIS AND TESTING).
Perform BODY VERIFICATION TEST - VER 1. (Refer to 8 - ELECTRICAL/ELECTRONIC CONTROL
MODULES/FRONT CONTROL MODULE - DIAGNOSIS AND TESTING).
Yes (Diesel Engines)
Perform the *No Response From ECM (PCI Bus) diagnostic procedure. (Refer to 8 - ELECTRICAL/
ELECTRONIC CONTROL MODULES - DIAGNOSIS AND TESTING).
Perform BODY VERIFICATION TEST - VER 1. (Refer to 8 - ELECTRICAL/ELECTRONIC CONTROL
MODULES/FRONT CONTROL MODULE - DIAGNOSIS AND TESTING).
No
>> Replace the A/C Heater Control in accordance with the Service Information.
Perform BODY VERIFICATION TEST - VER 1. (Refer to 8 - ELECTRICAL/ELECTRONIC CONTROL
MODULES/FRONT CONTROL MODULE - DIAGNOSIS AND TESTING).
DR/DH
HVAC - ELECTRICAL DIAGNOSTICS
24 - 95
Нет комментариевНе стесняйтесь поделиться с нами вашим ценным мнением.
Текст