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Don't Let The Click fool You
Posted to Technical Tips Forum on 3/22/2017 14 Replies

Today, a 2017 Malibu was towed in with a no crank failure. The customer told us that his mechanic said that the starter had failed as a click can be heard from the starter when the start button is pressed but the starter does not activate. It was towed to the dealer as it is still under warranty.

There were no codes set in any module. Looking at ECM data with key on engine off, i saw this...

[2017 Chevrolet Malibu LT, ECM/Inputs/Outputs Scan Data]

Looks normal. Now, how about when the starter button is pressed?

[2017 Chevrolet Malibu LT, ECM/Inputs/Outputs Scan Data]

OK,The ECM is receiving a start request and is activating the crank relay. I heard a click coming from the starter area. This is a stop/start vehicle and, as such, it uses two starter relays. One relay is used to engage the starter drive into the flywheel and the other is used to actually crank the starter. The starter solenoid has two control wires leading to it, one from each relay.

Why two relays? With the stop/start system, when the vehicle autostops, the pinion relay is activated, engaging the drive into the flywheel with the engine off. On the autostart, the other relay is activated, causing the starter to crank the vehicle. Why? because is shortens the crank time, making the autostart less noticeable. During a push button start, both relays are activated sequentially as a normal starter.

I pulled both relays and checked power inputs - OK. I jumped both relay connections and one caused the drive to extend and contract and made the click noise heard. Jumping the other relay connection caused the starter to free spin. This is normal operation. I hooked a test lamp to battery positive and probed the ground side of the starter relay and it illuminated with the start button pressed, showing that the ECM was activating the relay, but the relay was not functioning. A new relay solved the problem. No starter needed.

James from Florida

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car Vehicle Data

2017 Chevrolet Malibu LT 1.5L

Engine1.5 L