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.
- CHECK FOR AN ACTIVE DTC
- Turn the ignition on.
- With the scan tool, read DTCs and record on the repair order.
Is the DTC active or pending?
Yes
- Go To 2
No
- Perform the INTERMITTENT CONDITION diagnostic procedure. Refer to INTERMITTENT CONDITION .
- CHECK FOR OTHER DTCS
- Refer to the recorded DTCs.
Are there any 5-Volt reference DTCs active or pending?
Yes
- Perform the applicable diagnostic procedure(s). Refer to DTC INDEX - 2500 HD & 3500 HD .
No
- Go To 3
- Refer to the recorded DTCs.
- CHECK THE (F856) 5-VOLT SUPPLY CIRCUIT VOLTAGE
- Turn the ignition off.
- Disconnect the MAP Sensor harness connector.
- Turn the ignition on.
- Measure the voltage on the (F856) 5-Volt Supply circuit in the MAP Sensor harness connector.
Is the voltage between 4.9 to 5.1 volts?
Yes
- Verify that there is good pin to terminal contact in the MAP Sensor and Powertrain Control Module connectors. If no problems are found, replace the MAP Sensor in accordance with the Service Information. Refer to SENSOR, MANIFOLD AIR PRESSURE (MAP), REMOVAL .
- Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .
No
- Repair the (F856) 5-Volt Supply circuit for an open or high resistance.
- Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .