DL - Introduction

DL: Cylinder Head Temperature (CHT) Sensor
Introduction

DL: Pinpoint Tests DL - Test

WARNING: THIS VEHICLE IS EQUIPPED WITH HIGH VOLTAGE CABLES, COMPONENTS, AND WIRING. THE HIGH VOLTAGE WARNING LABELS CONTAINING THE HIGH VOLTAGE SYMBOL ARE LOCATED ON EACH HIGH VOLTAGE COMPONENT. HIGH VOLTAGE CABLES AND WIRING ARE ORANGE IN COLOR. CERTIFIED RUBBER INSULATING GLOVES AND A FACE SHIELD MUST BE WORN WHEN WORKING WITH THE HIGH VOLTAGE CABLES, COMPONENTS, OR WIRING. THE IGNITION KEY MUST BE CYCLED TO THE OFF POSITION FOR A MINIMUM OF 5 MINUTES, AND THE HIGH VOLTAGE TRACTION BATTERY SERVICE DISCONNECT PLUG PLACED IN THE SERVICING/SHIPPING POSITION BEFORE DISCONNECTING THE HIGH VOLTAGE CABLES. FAILURE TO FOLLOW THESE INSTRUCTIONS MAY RESULT IN PERSONAL INJURY OR DEATH.

DO NOT DISCONNECT, DISABLE, OR TOUCH THE HIGH VOLTAGE CABLES, COMPONENTS, OR WIRING DURING THE MODULE REPROGRAMMING PROCEDURE BECAUSE HIGH VOLTAGE IS PRESENT. THE HIGH VOLTAGE WARNING LABELS CONTAINING THE HIGH VOLTAGE SYMBOL ARE LOCATED ON EACH HIGH VOLTAGE COMPONENT. HIGH VOLTAGE CABLES AND WIRING ARE ORANGE IN COLOR. FAILURE TO FOLLOW THESE INSTRUCTIONS MAY RESULT IN PERSONAL INJURY OR DEATH.

This pinpoint test is intended to diagnose the following:

- CHT sensor (6G004)
- harness circuits: CHT, VREF, and SIGRTN
- powertrain control module (PCM) (12A650)
On applications that do not use an engine coolant temperature (ECT) sensor, the CHT sensor is used to determine the engine coolant temperature in place of the ECT sensor. To cover the entire temperature range of both the CHT and ECT sensors, the PCM has a dual switching resistor circuit on the CHT input. A graph showing the temperature switching from the COLD END line to the HOT END line, with increasing temperature and back with decreasing temperature is included. Note the temperature to voltage overlap zone. Within this zone it is possible to have either a COLD END or HOT END voltage at the same temperature. For example, at 90°C (194°F) the voltage could read either 0.60 volt or 3.71 volts. Refer to the table for the temperature to voltage expected values.





Voltage values calculated for VREF = 5 volts. These values can vary by 15% due to sensor and VREF variations.





Cylinder Head Temperature (CHT) Sensor Connector










Powertrain Control Module (PCM) Connector










DL: Pinpoint Tests DL - Test