Diagnose and fix remote start doesn’t work
GM has issued a service bulletin # PIT5308B to address remote start doesn’t work along with several other issues on the vehicles listed below. Those issues are:
Remove start doesn’t work
Power lift-gate doesn’t work with the ignition off. If the ignition is turned on, it will work correctly.
Vehicle starts and stalls
Cranks but won’t start
Blower motor stays on after shutting off vehicle (diesel engine). The blower motor may stay on after the engine is turned off, which may cause the battery to go dead.
Trouble codes P2537 P129D
Vehicles affected by service bulletin # PIT5308B
2015-2017 Cadillac Escalade
2014 Chevrolet Silverado 1500
2015-2017 Chevrolet Silverado
2015-2017 Chevrolet Suburban
2015-2017 Chevrolet Tahoe
2014 GMC Sierra 1500
2015-2017 GMC Sierra
2015-2017 GMC Yukon
GM service bulletin #PIT5308B
The #PIT5308B bulletin says that the above issues are caused because the ECM or the TCM are not receiving the 12 volt accessory wakeup signal from the BCM. To diagnose, use a voltmeter to check circuit 5985 at the ECM and TCM.
You should see approximately 12 volts with the BCM wake. Voltage may be present when you turn the key to off because the BCM may still be awake. This is normal. If you don’t see 12-volts, you’ll need a wiring diagram to test further. GM states that circuit 5985 is a low amperage signal circuit and it may not be able to power certain test lights or bulbs. The use of a voltmeter and small bulb, example 194 bulb, is required to test the circuit.
How to test the circuit
Connect a battery charger/maintainer and attach one side of a 194 bulb to circuit 5985 and the other side to a good ground (battery negative). Wake up the BCM (by turning the headlights on or turning the ignition on. The bulb should light. If the bulb does NOT light, you’ve got high resistance or an open in circuit 5985.
If the bulb lights, use a voltmeter and measure the voltage across the 194 bulb, to make sure there is at least 11 volts, if not inspect for high resistance/open in circuit 5985.
Most common failure is located under the driver’s side sill plate.Posted on by Rick Muscoplat