Pinpoint Test L: Incorrect Transmission Temperature Gauge Indication
Instrumentation, Message Center and Warning Chimes
Pinpoint Tests
Pinpoint Test L: 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 data from the PCM (4R70E/4R75E transmission) or the Transmission Control Module (TCM) (6R80 transmission) over the High Speed Controller Area Network (HS-CAN) communication bus. When the IC receives the transmission temperature data along with an engine rpm status over 500 rpm, the IC commands the transmission temperature gauge with a corresponding movement of the pointer.
If the transmission temperature data is missing or invalid for 5 seconds or less, or if the IC receives invalid transmission temperature data for 5 seconds or less, the IC defaults the transmission temperature gauge to the last setting, based upon the last known good transmission temperature message received.
NOTE: If DTC U0100 is set in the IC, other observable symptoms may be an inoperative speedometer, temperature gauge or tachometer.
If the IC does not receive the transmission temperature data message from the PCM (4R70E/4R75E transmission) or TCM (6R80 transmission) for more than 5 seconds, the IC sets DTC U0100 (PCM) or DTC U0101 (TCM) in continuous memory and defaults the transmission temperature to low (L).
If the transmission temperature data is deemed invalid by the IC for more than 5 seconds, the IC sets DTC U2023 and defaults the transmission temperature gauge to low (L).
This pinpoint test is intended to diagnose the following:
- Transmission Fluid Temperature (TFT) sensor (part of mechatronic assembly) (6R80 transmission)
- TFT sensor (part of the main control valve body) (4R70E/4R75E transmission)
- IC
PINPOINT TEST L: INCORRECT TRANSMISSION TEMPERATURE GAUGE INDICATION
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L1 RETRIEVE THE RECORDED DTCs FROM THE PCM AND TCM KOEO SELF-TEST
- Check the recorded PCM and TCM DTCs from the self-test.
- Are any DTCs recorded?
Yes
For PCM DTCs, REFER to Computers and Control Systems.
For TCM DTCs, REFER to Automatic Transmission/Transaxle &/or Transmission Control Systems.
No
GO to L2.
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L2 RETRIEVE THE RECORDED DTCs FROM THE IC SELF-TEST
- Check for recorded IC DTCs from the self-test.
- Are any DTCs recorded?
Yes
For DTC U0100, GO to Pinpoint Test AP. Pinpoint Tests AP: DTC U0100
For DTC U0101, GO to Pinpoint Test AQ. Pinpoint Tests AQ: DTC U0101
For all other DTCs, REFER to DTC Charts. Instrumentation, Message Center and Warning Chimes
No
GO to L3.
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L3 CHECK THE TCM TEMPERATURE PID
NOTE: This step may require the use of an assistant to monitor the transmission temperature PID and the transmission temperature gauge indication.
- Enter the following diagnostic mode on the scan tool: TCM DataLogger.
- Ignition ON.
- NOTE: The transmission temperature should range between -40 to 49°C (-40 to 120°F) with the gauge in the cold (C) range, between 10 to 120°C (120 to 248°F) with the gauge in the normal or mid-range and above 135 to 214°C (275 to 417°F) with the gauge in the hot (H) range.
- Select the TCM transmission temperature gauge PID (TFT).
- Beginning with a cold transmission, drive the vehicle while monitoring the TCM transmission temperature PID.
- Does the TCM PID agree with the position of the transmission temperature gauge indication at different temperature ranges?
Yes
GO to L4.
No
INSTALL a new IC. REFER to Instrument Cluster (IC) Instrument Cluster (IC). TEST the system for normal operation.
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L4 CHECK THE TRANSMISSION TEMPERATURE GAUGE USING THE IC DEALER TEST MODE
- Ignition ON.
- Enter the IC dealer test mode.
- Scroll through the displays to GAUGE TEST and monitor the transmission temperature gauge.
- Does the transmission temperature gauge sweep from the cold (C) stop to the hot (H) stop then return to cold (C)?
Yes
For 4R70E/4R75E transmissions, INSTALL a new main control valve body. REFER to Automatic Transmission/Transaxle &/or Transmission Control Systems. TEST the system for normal operation.
For 6R80 transmissions, INSTALL a new mechatronic assembly. REFER to Automatic Transmission/Transaxle &/or Transmission Control Systems. TEST the system for normal operation.
No
INSTALL a new IC. REFER to Instrument Cluster (IC) Instrument Cluster (IC). TEST the system for normal operation.
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