Diagnostic Test

WARNING: This page is about a different car, the 2017 RAM 2500 HD. However, it is still accessible from the selected car via links, so may be relevant.

Other DTCS
1. Turn The Ignition On.
2. With The Scan Tool, Read DTCS.
  Are Other DTCS Present?
  
  Yes
  - Repair Other DTCS First.
  - Perform The POWERTRAIN VERIFICATION TEST. Refer To POWERTRAIN VERIFICATION TEST .
  No
  - Go To 2
Check The 5-Volt Supply Circuit
1. Turn The Ignition Off.
2. Disconnect The A/C Pressure Sensor Harness Connector.
  NOTE:
  Check Connectors - Clean/Repair As Necessary.
3. Turn The Ignition On.
4. Measure The Voltage Between The (F856) 5-Volt Supply Circuit And (K400) Sensor Return Circuit Of The A/C Pressure Sensor Harness Connector.
  Is The Voltage Between 4.5 And 5.5 Volts?
  
  Yes
  - Go To 4
  No
  - Go To 3
Check The (F856) 5-Volt Supply Circuit For A Short To Voltage
1. Turn The Ignition Off.
2. Disconnect The PCM C2 Harness Connector.
  NOTE:
  Check Connectors - Clean/Repair As Necessary.
3. Turn The Ignition On.
4. Measure The Voltage Between The (F856) 5-Volt Supply Circuit At The Harness Connector And Ground.
  Is The Voltage Below 1.0 Volt?
  
  Yes
  - Go To 4
  No
  - Repair The (F856) 5-Volt Supply Circuit For A Short To Voltage.
  - Perform The POWERTRAIN VERIFICATION TEST. Refer To POWERTRAIN VERIFICATION TEST .
Check The (K400) Sensor Return Circuit For An Open/High Resistance
1. Turn The Ignition Off.
2. Measure The Resistance Of The (K400) Sensor Return Circuit Between The A/C Pressure Sensor Harness Connector And The PCM C2 Harness Connector.
  Is The Resistance Below 5.0 Ohms?
  
  Yes
  - Go To 5
  No
  - Repair The (K400) Sensor Return Circuit For An Open Or High Resistance.
  - Perform The POWERTRAIN VERIFICATION TEST. Refer To POWERTRAIN VERIFICATION TEST .
Check The (C18) Signal Circuit For A Short To Voltage
1. Turn The Ignition On.
2. Measure The Voltage Between The (C18) A/C Pressure Sensor Signal Circuit At The Harness Connector And Ground.
  Is The Voltage Below 1.0 Volt?
  
  Yes
  - Go To 6
  No
  - Repair The (C18) A/C Pressure Sensor Signal Circuit For A Short To Voltage.
  - Perform The POWERTRAIN VERIFICATION TEST. Refer To POWERTRAIN VERIFICATION TEST .
A/C Pressure Sensor
1. Reconnect The PCM C2 Harness Connector.
2. Turn The Ignition On.
3. With The Scan Tool, Record All Freeze Frame Data.
4. With The Scan Tool, Erase DTCS.
5. Turn The Ignition Off For 75 Seconds.
6. Turn The Ignition On.
7. While Monitoring Scan Tool, Use A Jumper Wire To Connect The (K400) Sensor Return Circuit To The (C18) A/C Pressure Sensor Signal Circuit At The A/C Pressure Sensor Harness Connector.
  Did P0532 Set?
  
  Yes
  - Replace The A/C Pressure Sensor.
  - Perform The POWERTRAIN VERIFICATION TEST. Refer To POWERTRAIN VERIFICATION TEST .
  No
  - Replace The Powertrain Control Module In Accordance With The Service Information.
  - Perform The POWERTRAIN VERIFICATION TEST. Refer To POWERTRAIN VERIFICATION TEST .