- DS - RAM 5 PICKUP - 4.7L MAGNUM V - DTC-Based Diagnostics/MODULE, Powertrain Control (PCM), NGC/Diagnosis and Testing P- SENSOR CIRCUIT HIGH AAT SENSOR GROUND BUS (+) BUS (-) ELECTRONICS POWER 4 C4 5 C4 C C D65 D64 G VT/LG G VT/BR WT/LG WT/LB TWISTED P G VT/BR TWISTED P AAT SENSOR AMBIENT GROUND D65 WT/LG D64 WT/LB 4 C BUS (+) 5 C BUS (-) CONTROL SENSOR GROUND ECT IAT 7 C C C K K VT/OR K DB/LG ENGINE COOLANT K K / /ORANGE LT. GRAY DK. GRAY CONTROL C (GAS) CONTROL C (GAS) 46 5 POWER C 5 47 6 POWER C4 ENGINE COOLANT AMBIENT 447 For a complete wiring diagram, refer to the Wiring Information.
Theory of Operation The Intake Air Temperature (IAT) Sensor diagnostic, under cold start conditions, following a start to run delay time, compares the outputs of the ambient, engine coolant and intake air temperature sensors. If the Engine Coolant and Ambient Air Temperature Sensors agree and the Intake Air Temperature Sensor does not agree, the Intake Air Temperature Sensor is declared as irrational. If declared irrational a second comparison will be done after a short drive cycle. When Monitored: With the ignition on. Battery voltage greater than.4 Volts. Set Condition: The Powertrain Control Module (PCM) detects that the Intake Air Temperature Sensor input voltage is above the maximum acceptable value. Possible Causes (K) IAT CIRCUIT SHORTED TO VOLTAGE (K) IAT CIRCUIT OPEN (K) SENSOR GROUND CIRCUIT OPEN (IAT) SENSOR CONTROL MODULE (PCM) Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding. (Refer to - DTC-Based Diagnostics/. ACTIVE DTC. 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 may result in possible serious or fatal injury. Diagnose and repair any system voltage DTCs before continuing with this test.. With the scan tool, select View DTCs. Is the DTC Active at this time? Yes Go To No Perform the INTERMITTENT CONDITION diagnostic procedure. (Refer to - DTC-Based Diagnostics/
. IAT SENSOR. Turn the ignition off.. Disconnect the Intake Air Temperature Sensor harness connector.. Ignition on, engine not running. 4. With the scan tool, read the IAT Sensor voltage. 5. Connect a jumper wire between the (K) IAT Signal circuit and the (K) Sensor ground circuit in the IAT Sensor harness connector. The sensor voltage should be approximately. Volts (plus or minus. Volt) with the jumper wire in place. Does the scan tool display the voltage as described above? Yes Verify that there is good pin to terminal contact in the Sensor and Powertrain Control Module connectors. Replace the IAT Sensor if no issues were found with the connectors. (Refer to 4 - Fuel System/Fuel Injection/SENSOR, Air Temperature - Removal). TEST. (Refer to - DTC-Based Diagnostics/ No Go To 557 Remove the jumper wire before continuing.
. (K) IAT CIRCUIT SHORTED TO VOLTAGE. Turn the ignition off.. Disconnect the C PCM harness connector.. Ignition on, engine not running. V 4. Measure the voltage on the (K) IAT Signal circuit in the IAT Sensor harness connector. Is there any voltage present? Yes Repair the short to voltage in the (K) IAT Signal circuit. TEST. (Refer to - DTC-Based Diagnostics/ No Go To 4 55 4. (K) IAT CIRCUIT OPEN OR EXCESSIVE RESISTANCE. Turn the ignition off. CAUTION: Do not probe the PCM harness connectors. Probing the PCM harness connectors will damage the PCM terminals resulting in poor terminal to pin connection. Install the PCM Pinout Box to perform diagnosis.. Measure the resistance of the (K) IAT Signal circuit from the IAT Sensor harness connector to the appropriate terminal of PCM Pinout Box 5A. 6 4 5 Is the resistance below 5. Ohms? Yes Go To 5 PCM PINOUT BOX 5 No Repair the open or excessive resistance in the (K) IAT Signal circuit. TEST. (Refer to - DTC-Based Diagnostics/ 56 4
5. (K) SENSOR GROUND CIRCUIT OPEN OR EXCESSIVE RESISTANCE. Measure the resistance of the (K) Sensor ground circuit from the IAT Sensor harness connector to the appropriate terminal of PCM Pinout Box 5A. Is the resistance below 5. Ohms? 7 Yes Go To 6 No Repair the open or excessive resistance in the (K) Sensor ground circuit. 6 5 TEST. (Refer to - DTC-Based Diagnostics/ 4 PCM PINOUT BOX 5 57 6. CONTROL MODULE (PCM). Using the wiring diagram/schematic as a guide, inspect the wiring and connectors between the IAT Sensor and the Powertrain Control Module (PCM).. Look for any chafed, pierced, pinched or partially broken wires.. Look for broken, bent, pushed out or corroded terminals. Verify that there is good pin to terminal contact in the Sensor and Control Module connectors. 4. Perform any Technical Service Bulletins that may apply. Were there any problems found? Yes Repair as necessary. TEST. (Refer to - DTC-Based Diagnostics/MODULE, Powertrain Control (PCM) - No Replace and program the Powertrain Control Module in accordance with the Service Information. TEST. (Refer to - DTC-Based Diagnostics/MODULE, Powertrain Control (PCM) - 5