Cadillac Cars & Trucks - Recent Questions, Troubleshooting & Support

Given the amount of electronics on your vehicle , control modules (computers ) serial data communication networks etc.... Me or anyone else on would only be guessing as to what the problem is . Starting with the basics to find a cause is always the best ! Checking for diagnostic trouble codes should always be the first step !
Reading how the systems work is always a good idea too . Especially for someone who has no idea how this vehicle works .

When you turn the key in the ignition low voltage inputs are sent to the module incharge the PMM - power mode master ! In you vehicles case it's the (DIM) dash integration module !
Table 1: 4-Wire Ignition Switch Table
Power to many of this vehicle's circuits are controlled by the module that is designated the Power Mode Master (PMM). This vehicle's PMM is the Dash Integration Module (DIM). The PMM controls which power mode (Run, Accessory, Crank, Retained Accessory Power, or Off) is active. In this vehicle the Rear Integration Module (RIM) assist the DIM in controlling the RAP power mode.

On vehicles that have several control modules connected by serial data circuits, one module is the power mode master (PMM). On this vehicle the PMM is the dash integration module (DIM). The PMM receives 4 signals from the ignition switch.
To determine the correct power mode the PMM uses the following circuits:
• Accessory voltage
• Ignition 1 voltage
• Ignition 3 voltage
• Off/Run/Crank voltage

Your best bet , take it to a qualified repair shop .

Cadillac DeVille... | Answered 3 hours ago

Ok first buy a Chiltions book for your car it will give you pictures and all the important info like what kind of transmission fluid you need, when to change your filters etc. NO your car should not be running wile changing the fluid! And don't get under it wile it's hot let is sit for an hour before you get under it and touch things if you aren't sure what you are touching there are parts that can burn you badly !! The star screws are called tork screws and take tork drivers to get them out. With a Chilitions and some prep work you can do it!

2006 Cadillac... | Answered 4 hours ago

a 6ya expert can help you resolve that issue over the phone in a minute or two.
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Cadillac Cars &... | Answered 9 hours ago

Bank 2 Sensor 1 is on the driver side - follow the right side of the engine down the headers which attaches to the catalytic converter. The o2 Sensor you're asking about (Bank 2 Sensor 1) is before the Catalytic. The o2 Sensor after the Catalytic is Bank 2 Sensor 2. Bank 1 Sensor 1 is on the passenger side as well as Bank 1 Sensor 2.

2003 Cadillac... | Answered 14 hours ago

On them older cars (and maybe still to some extent) they had a tiny voltage regulator on the instrument cluster board, just before the gas gauge and the temperature gauge. It cut the voltage going through those two gauges to about 5-7volts, before sending the signal out to the sending units.
For the in-tank sending unit, it had about 5 volts current running from the dash to the sending unit. The float on the sending unit attaches to a "variable resistor", and then goes to ground. What the dash gauge measures is the "resistance to ground", and is thus translated to the needle on the gauge showing anywhere from empty to full. Pretty neat, huh?
So if you are working on the gas gauge, you would check for that small voltage at the fuel tank electrical connector. Folks used to test whether the gauge or the sending unit was the problem by taking the wire at the tank and just temporarily grounding the wire to a ground, a clean metal piece of the frame down there. If it caused the needle to move AT ALL, then you would know that the problem is not the dash gauge, but the sending unit in the tank. Get a helper to watch the needle while you ground it. Careful not to let it ground too long-you can damage the gauge or voltage regulator. You just want to touch it to a clean piece of the frame while someone watches for needle movement-even just a little movement. Often this test would cause the needle to jump to full, or maybe just halfway, but any movement of the gauge needle means the gauge is okay. For this test, the ignition key must be on (not start, not engine running, just key in on).
The variable resistor on the sending unit is a little flimsy, and easily disrupted-that is why so many failed. A new one should not be very expensive-it is all one piece. You don't buy a separate resistor, you just buy the whole apparatus with the float and arm attached.
Probably 80-90% of the time, when the gas gauge stopped working, it was the sending unit, not the gauge itself.

Cadillac Cars &... | Answered 15 hours ago

Depends what sensors are on rear axle, suspension problem?

Cadillac Cars &... | Answered 24 hours ago

Did you clear the codes? Car may still be in limp mode...
Also the 303 is odd. Are the sparks good on #3? May have an issue with coil or ignition module.

Cadillac CTS... | Answered Yesterday

maybe low on coolant, check water to coolant ratio.

1988 Cadillac... | Answered Yesterday

SERVICE ENGINE SOON light has nothing to do with overheating or leaks ! OBD2 - emissions . DTC'S - diagnostic trouble codes stored in the PCM / ECM - engine computer . Probably a sensors or emission problem . Take an have it checked .

Cadillac... | Answered 2 days ago

BCM has nothing to do with this function , MMM - memory mirror module !
Memory Mirror System Operation
The MMM is capable of storing mirror position for 2 different drivers. Mirror position is determined by both horizontal and vertical position sensors in each of the power mirrors. The MMM supplies a reference voltage and a low reference to these sensors and determines mirror position through the horizontal and vertical position signal circuits.
The MMM receives power through the battery supply voltage circuit and the MIR/LOCK fuse and a constant ground source. Any time that battery voltage is disconnected and then connected from the MMM, the MMM will enter the mirror relearn mode. The mirror relearn mode can also be commanded using a scan tool. Refer to Memory Mirror Module Learn for further information.The memory switch receives power through the battery supply voltage circuit and the MIR/LOCK fuse. The MMM upon receipt of a memory switch signal input, a class 2 message from the SIC or a class 2 message from the PCM indicating that the transmission is in park, will then supply battery voltage and ground to the appropriate power mirror motors through the mirror motor control circuits to move the mirrors to the predetermined positions.

DTC B1586, B1596, B1616, or B1626
The mirror horizontal and vertical position sensors are potentiometers. The Memory Mirror Module (MMM) provides these sensors with a 5 volt reference circuit and a low reference circuit. The MMM monitors the horizontal and vertical position sensor signal circuits which change values based on mirror position. These voltage values are used to determine mirror position and can be set into memory. When the MMM receives a memory recall request, the MMM will control the power mirror to the memory position based on the horizontal and vertical position sensor signal values.

Install a scan tool.
Turn ON the ignition, with the engine OFF.
With the scan tool, observe the mirror horizontal and vertical position parameters in the Memory Mirror Module (MMM) data list.
Operate both the left and right mirrors through the full range of movements.
Does the scan tool indicate that the left and right mirror horizontal and vertical position parameters are within the specified range?

Memory Seat System Components
The memory seat system consists of the following components:
• Power seat switch assembly
• Memory recall switch assembly
• Horizontal adjuster motor
• Front vertical adjuster motor
• Rear vertical adjuster motor
• Recline adjuster motor
• Memory seat module
• Memory mirror module
• SEAT 25A circuit breaker
• MIR/LOCK 3A fuse

Your best bet , take it to a qualified repair shop !

2002 Cadillac... | Answered 2 days ago

After changing the thermostat you might have developed an air lock in the radiator. Does the radiator knock or push antifreeze out with the car running and the cap off. The water pump should also be checked and you can do that by looking in the radiator while running and with the cap off. You should see the fluid moving through the radiator if it is circulating Just be careful not to get burned if it pushes water out of the radiator.

Cadillac DeVille... | Answered 2 days ago

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