Test N: Incorrect Transmission Temperature Gauge Indication

PINPOINT TEST N: INCORRECT TRANSMISSION TEMPERATURE GAUGE INDICATION

Normal Operation
The transmission temperature gauge requires both transmission temperature and engine rpm data to operate the transmission temperature gauge. The instrument cluster (IC) receives the transmission temperature and the engine rpm data from the PCM over the high speed controller area network (HS-CAN) communication bus. When the instrument cluster (IC) receives the transmission temperature data along with an engine rpm status over 500 rpm, the instrument cluster (IC) commands the transmission temperature gauge with a corresponding movement of the pointer.

If the instrument cluster (IC) does not receive the transmission temperature or engine rpm data from the PCM for 5 seconds or less, the instrument cluster (IC) defaults the transmission temperature gauge to the last setting, based upon the last known good rpm message. If the instrument cluster (IC) does not receive the transmission temperature or engine rpm data from the PCM for more than 5 seconds, the instrument cluster (IC) sets DTC U0100 in continuous memory and defaults the transmission temperature gauge to the cold (C) stop position. If the transmission temperature or engine rpm data is deemed invalid by the instrument cluster (IC), the instrument cluster (IC) sets DTC U2023 and defaults the tachometer to the cold (C) stop position.

NOTE: If DTC U0100 is set in the instrument cluster (IC), other observable symptoms may be an inoperative speedometer, temperature gauge or tachometer.

This pinpoint test is intended to diagnose the following:
- PCM concern
- Instrument cluster (IC)

N1-N5: