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Home >> GMC >> 1991 >> Forward Control 6.2 J, Automatic >> Repair and Diagnosis >> External Pages >> Different car >> Section 82 (Engine Controls - Tests W/Codes - Body Control Computer) >> Self-Diagnostic Tests >> Test 17A - Testing CMTC Mileage & Economy Functions
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Test 17A - Testing CMTC Mileage & Economy Functions

WARNING: This page is about a different car, the 1995 Plymouth Voyager, 1995 Plymouth Grand Voyager, 1995 Dodge Grand Caravan, 1995 Dodge Caravan, and 1995 Chrysler Town & Country. However, it is still accessible from the selected car via links, so may be relevant.
NOTE: Perform TEST VER-1B after each repair.
  1. Using scan tool, read Powertrain Control Module (PCM) monitor. If scan tool does not display ACTIVE ON THE BUS, go to TEST 107A. If scan tool displays ACTIVE ON THE BUS, go to next step.
  2. Turn ignition on, engine off. Using scan tool, read ENGINE INFO. Observe Throttle Position (TP) sensor percent while moving throttle. If TP sensor percent does not increase as throttle is opened, see appropriate TESTS W/CODES article in ENGINE PERFORMANCE section below. If TP sensor percent increases as throttle is opened, go to next step.
  3. Raise and support vehicle to allow all wheels to spin freely. Start engine and place transmission in Drive. Using scan tool, read Vehicle Speed Signal (VSS) while raising vehicle speed. If MPH increases as throttle is opened, replace body control module. If MPH does not increase as throttle is opened, VSS circuit is inoperative. See appropriate TESTS W/CODES article in ENGINE PERFORMANCE section below.
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