Yukon Denali AWD V8-6.2L (2007)
following:
Important
Typical Freeze Frame operating conditions: ISS >500 RPM, OSS =0 RPM, Vehicle Speed >0 MPH
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Replace the Internal Mode Switch (IMS) if the Vehicle Build Date is prior to March 31, 2007. If not, continue with this bulletin.
Important
There is no calibration update for vehicles equipped with a 6L90 RPO MYD transmission or 2008 model year vehicles. These
calibrations were updated before production began.
-
Update the TCM calibration file to the latest released on TIS2WEB.
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After completing the above steps, test drive the vehicle, moving the shifter through all detent positions. If no issues are found, ensure all DTC
codes are cleared from history and return the vehicle to the customer.
4. If the DTC does not reset and original freeze frame data reports an IMS A/B/C/P code of LLLH, LLHL, LHLL or PNP Switch is P/N in all gears,
failure is a short to ground condition and is most likely in the Control Solenoid (with body and TCM) Valve Assembly (TEHCM), complete the
following:
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Obtain the following data and contact the PQC as the Control Solenoid (with body and TCM) Valve Assembly (TEHCM) is currently on
restriction. The PQC will engage engineering for additional diagnostic support.
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Capture or record freeze frame or fail records if a DTC is set.
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Document the diagnostics completed leading to the decision to replace the control solenoid valve and transmission control module.
Important
There is no calibration update for vehicles equipped with a 6L90 RPO MYD transmission or 2008 model year vehicles. These
calibrations were updated before production began.
-
Update the TCM calibration file to the latest released on TIS2WEB.
-
After completing the above steps, test drive the vehicle, moving the shifter through all detent positions. If no issues are found, ensure all DTC
codes are cleared from history and return the vehicle to the customer.
5. If the DTC does not reset and the original freeze frame data reports an IMS A/B/C/P code of LLLH and the vehicle is a 2009 CTS, STS or SRX,
the condition is most likely caused by an incorrectly adjusted shift linkage.
Important
Typical Freeze Frame operating conditions: ISS and OSS both =0 RPM or ISS and OSS both >0 RPM and/or vehicle is in some drive
gear (transmission gear ratio matches one of the forward gear ratios).
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Using a Tech 2(R), pull backward firmly/hard on the shifter to verify that the IMS A/B/C/P code remains at the correct HLLH reading. If it
toggles to LLLH or LLLL, the linkage is not adjusted properly.
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Perform the Shift Control Linkage Adjustment as detailed in SI.
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After adjustment, using a Tech 2(R), pull backward firmly/hard on the shifter to verify that the IMS A/B/C/P code remains at the correct
HLLH reading. If it toggles to LLLH or LLLL, the linkage is not adjusted properly. Repeat the adjustment.
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If no shifter adjustment issues are found, return to Step 4.
ACTIVE DTC/FAULT ACTIVE
If the fault is still active per Step 2 above, or after a test drive, continue with component tests defined below:
1. Ensure proper system performance:
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Inspect the shift cable for incorrect routing, kinks, severe bends and/or a damaged or twisted rubber boot at the transmission end of the cable.
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Check and ensure proper cable adjustment.
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Remove the transmission oil pan and repeat the shift lever movement, ensuring that the detent spring roller moves to the bottom of the valley
on the detent plate for each shift lever position. Inspect the detent spring roller and ensure it is centered on the detent plate. The spring arms
should not be rubbing on either the IMS arm or detent plate.
2. Disconnect the IMS connector at the Control Solenoid (w/body and TCM) Valve Assembly (TEHCM). With the Tech 2(R) connected and the
ignition ON and engine OFF, the Tech 2(R) should report all IMS states A/B/C/P as high (H) and the PNP Switch should display "In Gear".
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If any of the A/B/C/P circuits displays low (L), the TEHCM is faulty and should be replaced. If the Vehicle Build Date is prior to March 31,
2007, also replace the IMS.
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If the PNP Switch Circuit (Tech 2(R) Engine data) displays "Park/Neutral", a short exists in the TEHCM or the wiring connecting it to the
ECM. Disconnect the transmission pass-through connector. Check for continuity between the pass-through P/N Signal pin 3 (refer to
