Can you explain why? There is no engine management light on, car drives fine.

 

(Need a mod to edit the thread title please)


P0884-POWER UP AT SPEED

For a complete wiring diagram Refer to the Wiring Information.

Theory of Operation


If a vehicle loses power to the PCM, the vehicle will go to the 2nd gear mode since there is no power available to control the transmission solenoids. However if power is restored, the PCM will power-up and normal operation will be restored. This DTC identifies that power to the PCM was restored when the gear selector was in a "Drive" position while the vehicle was moving at speeds above 32 Km/h (20 MPH). If a customer shifts to Neutral and cycles the ignition key and quickly shifts to "Drive" while moving before the PCM comes out of its START ROUTINE, the DTC can be set. Therefore it is critical that this DTC diagnosis repair procedure should only be used if the vehicle is experiencing intermittent 2nd gear operation and subsequently a return to normal operation during normal driving. The transmission will not be placed in Limp-in. This is an informational DTC to be used when attempting to diagnose an intermittent 2nd gear operation and subsequent return to normal transmission operation.

• When Monitored: One time after each controller reset. Note: the Transmission Control Module is integrated with Powertrain Control Module. The Transmission Control Module has separate powers and grounds specifically to its portion of the PCM.
• Set Condition: This DTC will set if the PCM powers up and senses the vehicle in a valid forward gear (no PRNDL DTCs) with an output speed above 800 rpm, approximately 32 Km/h or 20 mph.

Possible Causes

INTERMITTENT POWER AND GROUND CIRCUITS


CHECK THE POWER AND GROUND CIRCUITS


1. This DTC is set when the PCM is initialized while the vehicle is moving in a valid forward gear. This is usually caused by a momentary loss of power to the Transmission portion of the PCM.




NOTE: Due to the integration of the Powertrain and Transmission Control Modules, the transmission part of the PCM has its own specific power and ground circuits.



2. Check all of the Fused B(+), Fused Ignition Switch Output, and Ground circuits related to the PCM for an intermittent open or short to ground.

3. Perform a wiggle test on all wiring and connectors pertaining to the PCM while looking for shorted or open circuits.

4. With the scan tool, check the DTC EVENT DATA to help identify the conditions in which the DTC was set.
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If there is an available flash for your van, they will do it first then send you on your way before doing anything else. This CAN be caused by internal TCM/PCM.

 

Ok, thanks. I'll see what they say on Wednesday