Diagnostic Aids
Intermittent faults must be continuously present for at least 20 seconds to cause Code 26 to set. QDM controlled circuits should be inspected for poor terminal contact or damaged harness. The TCC circuit should be checked with the transaxle at operating temperature if Code 26 sets intermittently and no other cause is found, as a defective TCC solenoid resistance can drop too low (below 20 ohms) at high temperature. QDM faults can be detected as noted on CODE 26 chart (Page 1 of 3) and when outputs are on or off as follows:
- Open circuit or control circuit short to ground-output commanded off.
- Shorted device or control circuit short to voltage-output commanded on.
NOTE:
QDM B fault line on an automatic transaxle vehicle will normally be "high" when the vehicle is stopped. The ECM ignores the QDM B fault line except under conditions noted above.