E039 Part 1 of 2

Code E39:

VCC Brake Switch Circuit:

DESCRIPTION:

This diagnostic test monitors VCC engagement for a problem by comparing the engine speed to a speed which should not be possible to achieve unless the viscous clutch is slipping excessively. If a VCC failure has occurred, the failure is more likely to be observed under high road load (high MAP) conditions.

TEST CONDITIONS:

1. Codes E26, E27, E31, E32, and E34 not set.
2. Trans in fourth gear.
3. Closed loop.
4. Brake off.
5. Engine rpm 3100 or less.
6. MAP between 29 kPa and 80 kPa.
7. VCC commanded ON.
8. VCC mod solenoid at 100% duty cycle.

FAILURE CONDITIONS:

The code sets when the engine rpm is greater than engine speed.

ACTION TAKEN:

1. PCM turns on the "SERVICE ENGINE SOON" telltale.
2. VCC is disabled for the entire ignition cycle.

NOTES ON FAULT TREE:

1. The next chart will test the resistance of the VCC solenoids and wiring inside the transmission. The road test checks for proper transmission operation.

NOTE ON INTERMITTENTS:

Intermittent operation may be caused by a connector terminal that has not been properly crimped or seated in its connector body. Use PCM output cycling E.0.2 to activate the circuits. Manipulate the wiring and connectors, and observe the transmission test box indicators for a malfunction in a circuit. If electrical fault cannot be duplicated, road test vehicle using J38791 trans test box (or equivalent). The PCM and wiring can be bypassed by using the rotary switch to manually select gears and VCC to test the transmission for intermittent operation.