Pinpoint Test E: Incorrect Temperature Gauge Indication

Instrumentation, Message Center and Warning Chimes

Pinpoint Test E: Incorrect Temperature Gauge Indication

Normal Operation

The PCM receives the engine coolant temperature status through hardwired circuitry to the Cylinder Head Temperature (CHT) sensor. The PCM sends the engine coolant temperature data to the Instrument Cluster (IC) over the High Speed Controller Area Network (HS-CAN) communication bus. The engine temperature data received from the PCM is filtered by the cluster to reduce gauge fluctuations. There are two separate strategies that the PCM and IC (Instrument Cluster) use to control the temperature gauge. The first strategy is basic engine temperature, which provides gradual changes in the temperature gauge based upon changing engine temperature. The second strategy is the fail-safe cooling mode, which commands the gauge to the hot (H) stop position. If the IC (Instrument Cluster) does not receive the engine temperature status or if the temperature data is deemed invalid by the IC (Instrument Cluster) for more than 5 seconds, the message is considered missing and the IC (Instrument Cluster) sets DTC U0100 and defaults the temperature gauge to the cold (C) stop.

- DTC U2199 (Invalid Engine Coolant Temperature Data)- a continuous DTC that sets if the IC (Instrument Cluster) receives invalid engine temperature data from the PCM. The IC (Instrument Cluster) defaults the temperature gauge to the cold (C) stop.

This pinpoint test is intended to diagnose the following:

- PCM concern

- IC (Instrument Cluster)

PINPOINT TEST E : INCORRECT TEMPERATURE GAUGE INDICATION

E1 RETRIEVE THE RECORDED DTCs FROM THE IC (Instrument Cluster) SELF-TEST

- Check for recorded IC (Instrument Cluster) DTCs from the self-test.

Is DTC U0100 recorded?

Yes
GO to Pinpoint Test AT. Pinpoint Test AT: DTC U0100

For DTC U2199, RETRIEVE and REPAIR all non-network DTCs in the PCM and other modules on the network.

For all other DTCs, REFER to DTC Charts. Instrumentation, Message Center and Warning Chimes

No
GO to E2.

E2 RETRIEVE THE RECORDED DTCs FROM THE PCM KOEO (Key ON Engine OFF) SELF-TEST

- Check for recorded PCM DTCs from the Key ON Engine OFF (KOEO) self-test.

Are any DTCs recorded?

Yes
REFER to Computers and Control Systems Information.

No
GO to E3.

E3 CARRY OUT THE IC (Instrument Cluster) TEMPERATURE GAUGE ACTIVE COMMAND USING THE SCAN TOOL

- Ignition ON.

- Enter the following diagnostic mode on the scan tool: IC (Instrument Cluster) DataLogger.

- Select the IC (Instrument Cluster) temperature gauge (ENGCOOLNT) active command and scroll in 3 increments 0°C (0°F), 105°C (221°F), and 134°C (273°F).

Does the temperature gauge start at cold (C) when at 0°C (0°F), move to approximately half at 105°C (221°F), and full hot (H) at 134°C (273°F)?

Yes
GO to E4.

No
INSTALL a new IC (Instrument Cluster). REFER to Instrument Cluster (IC) . TEST the system for normal operation.

E4 CARRY OUT THE IC (Instrument Cluster) DEALER TEST MODE

- Start the engine.

- Enter the IC (Instrument Cluster) dealer test mode with the Key ON Engine Running (KOER) by pressing and holding the odometer/trip odometer reset button (base cluster) or the message center switch RESET button (message center cluster) while starting the engine. Scroll through the displays until COOLANT TEMP is displayed and record the temperature value at different engine temperatures.

Do the self-test temperature input values match the temperature gauge indication?

Yes
The temperature gauge is operating correctly at this time.

No
INSTALL a new IC (Instrument Cluster). REFER to Instrument Cluster (IC) . TEST the system for normal operation.