2003 buick rendezvous wont crank. error on prnd123 display
The proper thing to do would be to hook up a factory or professional type scanner an check input data to the PCM from the Transmission internal mode switch . Error means the instrument cluster is loosing data from the PCM - engine computer .
The lever assembly-manual shaft detent with internal mode switch (IMS) is a sliding contact electrical switch assembly that corresponds to the PRNDL position selected. Each of the PRNDL positions has a unique ground pattern on four wires from the PCM.
The assembly consists of two major components:
• The internal mode switch that consists of:
- The housing (1), which makes up the stationary contacts.
- The insulator (2), which makes up the moving contacts and is secured on the detent lever (4).
• The lever assembly which consists of:
- The manual shaft (3)
- The detent lever (4)
The range detection is accomplished by securing the moving contacts to the detent lever. When the driver selects a PRNDL position, the detent lever inside the transmission rotates. This rotates the insulator which in turn grounds the four wires in a unique pattern for each gear selection, corresponding to the PRNDL position selected. The IMS is electrically connected by five wires (four of which the PCM supplies voltage to and one wire that is a common ground) to the transmission pass through connector.
Range Selector Displays Incorrect Range
The transmission internal mode switch (IMS) is a sliding contact switch attached to the selector detent inside the transmission side cover. The four inputs to the PCM indicate the position of the transmission range selector. The input voltage level at the PCM is high, B+, when the IMS is open and low when the switch is closed to ground. The four input parameters represented are Signals A, B, C and P, Parity. Refer to Transmission Internal Mode Switch Logic .
Install a scan tool.
Turn ON the ignition, with the engine OFF.
Select IMS on the scan tool.
Place the range selector in each transmission range: P, R, N, D4, D3, D2 and D1.
Does each range selected match the scan tool IMS display?
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Go to Intermittent Conditions in Engine Controls - 3.4L
Go to Step 2
2
Select IMS A/B/C/P on the scan tool.
Place the range selector in each transmission range: P, R, N, D4, D3, D2 and D1.
Does the IMS A/B/C/P display the specified values for each range?
Your best bet , take your vehicle to a qualified repair shop.