Diagnostic Test
- CHECK FOR AN ACTIVE DTC NOTE:
Make sure the A/C refrigerant System is properly charged in accordance with the Service Information. Refer to TECHNICAL SPECIFICATIONS .
- Start the engine and allow it to reach normal operating temperature.WARNING:
When the engine is operating, do not stand in direct line with the fan. Do not put your hands near the pulleys, belts, or fan. Do not wear loose clothing. Failure to follow these instructions can result in possible serious or fatal injury.
- With the scan tool, select View DTCs.
Is the DTC Active at this time?
Yes
- Go To 2
No
- Perform the INTERMITTENT CONDITION diagnostic procedure. Refer to INTERMITTENT CONDITION .
- Start the engine and allow it to reach normal operating temperature.
- CHECK FOR OTHER DTCS
- Refer to the recorded DTCs.
Are there any CAN bus, communication, implausible signal, system voltage or sensor reference voltage DTCs active or pending?
Yes
- Perform the applicable diagnostic procedure(s). Refer to DTC INDEX - 2500 HD .
No
- Go To 3
- Refer to the recorded DTCs.
- CHECKTHE (K855) 5 VOLT SUPPLY CIRCUIT FOR PROPER VOLTAGE
- CHECK THE (K855) 5-VOLT SUPPLY CIRCUIT FOR A SHORT TO GROUND
- Turn the ignition on.
- Disconnect the PCM C1 harness connector.
- Measure the resistance between ground and the (K855) 5-Volt Supply circuit in the A/C Pressure Transducer harness connector.
Is the resistance above 1000 Ohms?
Yes
- Go To 5
No
- Repair the (K855) 5-Volt Supply circuit for a short to ground.
- Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .
- CHECK THE (K855) 5-VOLT SUPPLY CIRCUIT FOR A SHORT TO THE (K914) SENSOR GROUND CIRCUIT
- Measure the resistance between the (K855) 5-Volt Supply circuit and the (K914) Sensor Ground circuit in the A/C Pressure Transducer harness connector.
Is the resistance above 100 Ohms?
Yes
- Go To 6
No
- Repair the short between the (K855) 5-Volt Supply circuit and the (K914) Sensor Ground circuit.
- Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .
- Measure the resistance between the (K855) 5-Volt Supply circuit and the (K914) Sensor Ground circuit in the A/C Pressure Transducer harness connector.
- CHECK THE (K855) 5-VOLT SUPPLY CIRCUIT FOR AN OPEN OR HIGH RESISTANCE
- Measure the resistance of the (K855) 5-Volt Supply circuit between the A/C Pressure Transducer harness connector and the PCM C1 harness connector.
Is the resistance below 5.0 Ohms?
Yes
- Go To 11
No
- Repair the (K855) 5-Volt Supply circuit for an open circuit or high resistance.
- Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .
- Measure the resistance of the (K855) 5-Volt Supply circuit between the A/C Pressure Transducer harness connector and the PCM C1 harness connector.
- CHECK THE (C18) A/C PRESSURE SENSOR SIGNAL CIRCUIT FOR A SHORT TO GROUND
- Turn the ignition off.
- Disconnect the PCM C1 harness connector.
- Measure the resistance between ground and the (C18) A/C Pressure Sensor Signal circuit in the A/C Pressure Transducer harness connector.
Is the resistance above 1000 Ohms?
Yes
- Go To 8
No
- Repair the (C18) A/C Pressure Sensor Signal circuit for a short to ground.
- Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .
- CHECK THE (C18) A/C PRESSURE SENSOR SIGNAL CIRCUIT FOR A SHORT TO THE (K914) SENSOR GROUND CIRCUIT
- Measure the resistance between the (C18) A/C Pressure Sensor Signal circuit and the (K914) Sensor Ground circuit in the A/C Pressure Transducer harness connector.
Is the resistance above 1000 Ohms?
Yes
- Go To 9
No
- Repair the (C18) A/C Pressure Sensor Signal circuit for a short to the (K914) Sensor Ground circuit.
- Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .
- Measure the resistance between the (C18) A/C Pressure Sensor Signal circuit and the (K914) Sensor Ground circuit in the A/C Pressure Transducer harness connector.
- CHECK THE (C18) A/C PRESSURE SENSOR SIGNAL CIRCUIT FOR AN OPEN OR HIGH RESISTANCE
- Measure the resistance of the (C18) A/C Pressure Sensor Signal circuit between the A/C Pressure Transducer harness connector and the PCM C1 harness connector.
Is the resistance below 5.0 Ohms?
Yes
- Go To 10
No
- Repair the (C18) A/C Pressure Sensor Signal circuit for an open circuit or high resistance.
- Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .
- Measure the resistance of the (C18) A/C Pressure Sensor Signal circuit between the A/C Pressure Transducer harness connector and the PCM C1 harness connector.
- CHECK THE AC PRESSURE TRANSDUCER FOR PROPER OPERATION
- Turn the ignition off.
- Connect the PCM C1 harness connector.
- Connect a jumper wire between the (K855) 5-Volt Supply circuit and the (C18) A/C Pressure Sensor Signal circuit in the A/C Pressure Transducer harness connector.
- Turn the ignition on.
- With the scan tool, read the AC Pressure Transducer signal voltage.
Is the voltage above 4.5 Volts with the jumper wire in place?
Yes
- Replace the A/C Pressure Transducer in accordance with the Service Information. Refer to TRANSDUCER, A/C PRESSURE, REMOVAL .
- Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .
No
- Go To 11
- CHECK RELATED HARNESS CONNECTIONS
- Disconnect all PCM harness connectors.
- Disconnect all related in-line harness connections (if equipped).
- Disconnect the related component harness connectors.
- Inspect harness connectors, component connectors, and all male and female terminals for the following conditions:
- Proper connector installation.
- Damaged connector locks.
- Corrosion.
- Other signs of water intrusion.
- Weather seal damage (if equipped).
- Bent terminals.
- Overheating due to a poor connection (terminal may be discolored due to excessive current draw).
- Terminals that have been pushed back into the connector cavity.
- Check for spread terminals and verify proper terminal tension.
Repair any conditions that are found.
- Connect all PCM harness connectors. Be certain that all harness connectors are fully seated and the connector locks are fully engaged.
- Connect all in-line harness connectors (if equipped). Be certain that all connectors are fully seated and the connector locks are fully engaged.
- Connect all related component harness connectors. Be certain that all connectors are fully seated and the connector locks are fully engaged.
- With the scan tool, erase DTCs.
- Test drive or operate the vehicle in accordance with the when monitored and set conditions.
- With the scan tool, read DTCs.
Did the DTC return?
Yes
- Replace and program the Powertrain Control Module (PCM) in accordance with the Service Information. Refer to MODULE, POWERTRAIN CONTROL (PCM), REMOVAL .
- Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .
No
- The wiring or poor connection problem has been repaired.
- Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .