Upshift Lamp Circuit Fault

DTC P1650 And/Or O1651 - Upshift Lamp Circuit Fault:

Upshift Lamp Circuit Fault (Chart 3 Of 5):

A quad driver module is an electronic switch which completes a ground circuit when switched On. The QDM independently controls four separate outputs. A load is connected between battery voltage and the QDM allowing the driver to control the output. Each QDM has fault detection logic which compares driver input and Output voltages. The logic expects to measure less than 3.0 volts when the driver is On and greater than 7.0 volts when Off. Each QDM has only one fault line that will detect a fault on any of the four outputs. The Scan tool can also perform an automated test which will isolate the faulty output circuit.

DTC Parameters
DTC P1650 and/or P1651 will set if:
^ There is an open short to ground or short to voltage or the QDM output upshift lamp circuit.

IMPORTANT: The QDM circuit is continuously checked when the engine is running.

Diagnostic Aids
^ Right hand drive vehicles are not equipped with upshift lamp and circuit 456.
^ If one output is bad the PCM will shut down only that QDM Output and not the entire quad driver unless the quad driver reaches its thermal limit (short to voltage). At this time it will turn all four quad driver outputs Off When the quad driver cools down it will turn back On and this process will start over.
^ Check 10 amp IGN 1 fuse in the IPJB.
^ A shorted or Open, relay Of bulb can cause a DTC 1650/1651 to set.

Check the tightness of the female terminal grip with a spare male terminal.

Use the scan tool to diagnose the quad driver circuits and perform an off-board QDM test.

For example, if the MIL (SERVICE ENGINE SOON) lamp is Off, the PCM expects to see 12 volts on the circuit line. If the circuit is open, 0 volts will be seen and the fault will be displayed. However, if the lamp is turned On, the PCM expects to see 0 volts on the circuit, and will not detect a fault. This causes an intermittent problem because the lamp is not continuously On.