chdonley

'02 2500hd 6.0l. 125k mi. Got SES light w/knock sensor code. Replaced both sensors and harness, reset code but SES came back on after 10 miles. Replaced both sensors again, figuring I must have overtightened first time.
Carefully installing second pair and resetting code but same result. SES after a few miles. Knock sensor codes again. I searched threads and see that this is a common problem w/these vehicles but I haven't seen the solution. I checked sensor output volts and resistance, continuity to PCM pins, all good. How/what have you guys done to clear this problem? Thanks, Chuck Donley

in2pro

Welcome to the forum...
Can you post all the codes you are getting...
sometimes the codes only indicate what the computer thinks the problems based on input.... but it can be something unrelated like a bad catalytic converter or bad fuel or an incorrect alcohol reading for the fuel....

UWAdventurer

I had a knock sensor problem years ago on a Chevrolet and it turned out it was the brand of oil I was using. I wouldn't have believed it except when I spoke to my mechanic he guessed the brand of oil I was using before I told him. I went immediately, purchased a different brand, changed the oil myself as I always did, went back to my mechanic he checked the engine again, no knock sensor problem. I never had the problem again using the second brand of oil.

chdonley

Son in-law subaru tech. took code reader to racing this weekend. will read and post all codes tomorrow, 5/17/13 thanks, chuck donley

chdonley

Throwing codes 327, 332. the kid suspects bad wiring harness (intermittent open or ground) or worst case, bad computer. bybassing stock wiring today, reset codes tonignt for another run at it.
chuck donley

MDTAHOE

You need to run down the trouble trees associated with the codes. Below I will post the them best I can if you can not read them the you need to get a service manual.


CIRCUIT DESCRIPTION
The knock sensors (KS) produce an AC signal under all engine operating conditions. The powertrain control module (PCM) calculates the average voltage range of each KS signal. If the KS system is operating normally, the PCM should monitor the KS voltage varying above and below calculated average voltage. If the PCM detects a KS 1 signal or a KS 2 signal voltage within the calculated average range, a DTC will be set. DTC P0327 refers to the front KS. DTC P0332 refers to the rear KS.

CONDITIONS FOR RUNNING THE DTC
DTCs P0117, P0118, P0121, P0122, P0123, P0125, P1114, P1115, P1121, P1122, or P1258, are not set.
The minimum noise level must be learned. The minimum noise level is learned when the following conditions are met:
The engine coolant temperature (ECT) must be greater than 60°C (140°F) .
The engine RPM is between 475-975 for 10 seconds .
The engine speed is between 1,500-3,000 RPM .
The manifold absolute pressure (Map) is less than 49 kPa .
The engine coolant temperature (ECT) is more than 60°C (140°F) .
The throttle angle is more than 0 percent .
The engine run time is more than 10 seconds .
The ignition voltage is more than 10 volts .
CONDITIONS FOR SETTING THE DTC
The PCM determines that this signal is less than the expected amount for more than 9 seconds .

ACTION TAKEN WHEN THE DTC SETS
The control module illuminates the malfunction indicator lamp (MIL) on the second consecutive ignition cycle that the diagnostic runs and fails.
The control module records the operating conditions at the time the diagnostic fails. The first time the diagnostic fails, the control module stores this information in the Failure Records. If the diagnostic reports a failure on the second consecutive ignition cycle, the control module records the operating conditions at the time of the failure. The control module writes the operating conditions to the Freeze Frame and updates the Failure Records.
CONDITIONS FOR CLEARING THE MIL/DTC
The control module turns OFF the malfunction indicator lamp (MIL) after 3 consecutive ignition cycles that the diagnostic runs and does not fail.
A current DTC, Last Test Failed, clears when the diagnostic runs and passes.
A history DTC clears after 40 consecutive warm-up cycles, if no failures are reported by this or any other emission related diagnostic.
Clear the MIL and the DTC with a scan tool.
DIAGNOSTIC AIDS

IMPORTANT: If the KS is dropped, the sensor must be replaced.

Inspect the KS for proper installation. A knock sensor that is loose or over torqued may cause the DTC to set.
If DTCs P0327 and P0332 are set at the same time, inspect for poor connections at the KS harness jumper, located at the left rear side of the intake manifold.
For an intermittent, refer to Intermittent Conditions. See: Powertrain Management\Computers and Control Systems\Testing and Inspection\Initial Inspection and Diagnostic Overview\Diagnostic Strategies\Intermittent Conditions
TEST DESCRIPTION


DTC P0327 Or P0332 - Steps 1-7

MDTAHOE

The numbers below refer to the step numbers on the diagnostic table.
2. This verifies the malfunction is present.
3. This test will isolate the KS from the rest of the circuit.
4. Tapping on the engine block will simulate an engine knock.

chdonley

Thanks for the info. that ought to keep the kid busy for a while. will post when a fix is achieved.

chdonley

After all the time(and money) spent chasing possible fixes the answer was as simple as replacing the cheap ebay sensors w/ OEM AC/Delco sensors. Problem solved, codes cleared, truck running normal. Thanks everyone for the help. chuck donley