LEMON Manuals: Even more car manuals for everyone
Home >> GMC >> 2003 >> Safari Van Cargo, AWD >> Repair and Diagnosis >> External Pages >> Different car >> Section 87 (Automatic Transmission Diagnosis - ALLISON) >> Diagnostic Tests >> DTC P0706: Transmission Range Sensor Circuit Performance (2001) >> Diagnostic Procedure

Diagnostic Procedure

WARNING: This page is about a different car, the 2002 GMC Sierra, 2002 GMC Cab & Chassis Sierra, 2002 Chevrolet Silverado, and 2002 Chevrolet Cab & Chassis Silverado. However, it is still accessible from the selected car via links, so may be relevant.
  1. Did you perform the diagnostic system check? If so, go to next step. If not, see DIAGNOSTIC SYSTEM CHECK  under SELF-DIAGNOSTIC SYSTEM.
  2. Is the PNP switch and shift linkage properly adjusted? See PARK/NEUTRAL POSITION SWITCH under ADJUSTMENTS in appropriate AUTOMATIC article in TRANSMISSION SERVICING. If so, go to next step. If not, adjust as necessary and retest.
  3. Install the scan tool. Turn ignition on, engine off. Record the DTC failure records. Using the scan tool, monitor PRNDL "A", "B", "C", "P" status while moving the gearshift lever through each position. Does each switch toggle on and off in the correct sequence and does the gear range displayed on the scan tool match the actual gear range for the gearshift lever position chosen? See Figure. If so, see DIAGNOSTIC AIDS . If not, go to next step.
  4. Turn ignition off. Disconnect the TCM C2 connector. Install Breakout Box (J-39700) and Breakout Box Adapter (J-43799). Turn ignition on. In sequence, connect TCM connector C2 terminal No. 20 to terminals No. 5, 6, 7, and 8. Using the scan tool, monitor PRNDL "A", "B", "C", "P" status. Does each switch toggle on and off in the correct sequence as each terminal is grounded? If so, go to next step. If not, go to step  8.
  5. Turn ignition off. Reconnect the C2 connector to the TCM. Disconnect the connectors at the PNP switch. Turn ignition on. In sequence, connect 4-way PNP connector terminals 4A, 4B, 4C, and 4D to 7-way PNP connector terminal 7D. Using the scan tool, monitor PRNDL "A", "B", "C", "P" status. Does the scan tool indicate the status as ON? If so, go to next step. If not, go to step  7.
  6. Replace the PNP switch. See PARK/NEUTRAL POSITION SWITCH  under REMOVAL & INSTALLATION. Is the replacement complete? If so, go to step  9.
  7. Inspect and repair the transmission wiring harness assembly. Replace the wiring harness if necessary. Is the repair complete? If so, go to step  9.
    8. CAUTION: In most cases, the TCM is not at fault. Investigate thoroughly before replacing the TCM.
  8. Replace the TCM. See TRANSMISSION CONTROL MODULE  under REMOVAL & INSTALLATION. Is the replacement complete? If so, go to next step.
  9. Perform the following procedure to verify the repair:
    • Clear the DTC.
    • Using the scan tool, monitor PRNDL "A", "B", "C", "P" status while moving the gearshift lever through each position.

    Does each switch toggle on and off in the correct sequence as the gearshift lever is moved? See Figure. If so, system is okay. If not, go to step  1.

scientia non olet · About LEMON Manuals